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BallinWithNash
11-17-2009, 09:45 PM
Hey, guys what takes more power to reproduce .... a high note or a low note?
So in other words the lower the note the more power or the higher the note the more power?

dakatabg
11-17-2009, 09:50 PM
I don't know exactly what you mean? Are you talking about the piano or saxophone notes or what?

BallinWithNash
11-17-2009, 09:53 PM
i mean in general for an amplifier does it take more power as in watts to produce a high note or a low note

dakatabg
11-17-2009, 09:57 PM
It takes more to reproduce low

BallinWithNash
11-17-2009, 10:05 PM
Now guys can you please help me out haha
http://www.youtube.com/comment_servlet?all_comments&v=Ly3VRsPCKiU&fromurl=/watch%3Fv%3DLy3VRsPCKiU%26feature%3Demail

Just cntrl F and type in BallinWithNash and read the short conversation
Thank you in advance!

harley .guy07
11-18-2009, 02:14 AM
Well in general it takes more power to reproduce lower notes since the signal wave is slower and the speaker motor structure and driver is larger in lower frequency producing units and it takes more power to move bigger drivers at slower speeds. Its pretty simple logic really. It takes a bigger more powerful motor to make a bigger car run faster or the same speed as a smaller car with a smaller motor. That is why powered subwoofers have anywhere from a couple hundred watts to over 1000 and most home audio 2 channel amps do not go much over 350 per channel and thats a big amp, generally 100 to 150 is generally where most people have their systems and thats usually all thats needed unless you are running some really big power pig speakers or play your music very loud.

E-Stat
11-18-2009, 05:58 AM
Now guys can you please help me out haha
You are correct, but understand that the uh, *program material* played on car stereos rarely contains first octave bass at the same level as the mid bass. So, for an average recording, the mid bass might require more excursion overall than a more demanding, but lower level signal.

I was amused by the guy's "woofer moves faster at higher frequencies" explanation. :)

rw

Ajani
11-18-2009, 07:19 AM
I was amused by the guy's "woofer moves faster at higher frequencies" explanation. :)

Are we sure BallinWithNash isn't arguing with Pixelthis on that site? That woofer moves faster explanation sounds very similar to an argument Pix had about why tweeters need more power than woofers....

I think the reason people come to the conclusion Pix and the guy on youtube do, is because they confuse Continuous Power with Peak Power... Tweeters and Mid Range Drivers will tend to require low but continuous power as they are constantly moving. Bass Drivers will be moving less frequently but require large bursts of power when they do move. So at the end of a 5 minute song, the TOTAL power used by the Tweeters/Mid might have exceeded the Bass driver.

GMichael
11-18-2009, 07:56 AM
Are we sure BallinWithNash isn't arguing with Pixelthis on that site? That woofer moves faster explanation sounds very similar to an argument Pix had about why tweeters need more power than woofers....

I think the reason people come to the conclusion Pix and the guy on youtube do, is because they confuse Continuous Power with Peak Power... Tweeters and Mid Range Drivers will tend to require low but continuous power as they are constantly moving. Bass Drivers will be moving less frequently but require large bursts of power when they do move. So at the end of a 5 minute song, the TOTAL power used by the Tweeters/Mid might have exceeded the Bass driver.

That's what I was thinking too. Tweeters don't demand a sudden burst of power to drive a 12 inch speaker and shake the house. This demand is why people who want to play deep bass loudly need big amps.

harley .guy07
11-18-2009, 10:46 AM
that was pretty much the point I was trying to make but e-stat,Ajani,Gmichael just had a better way of explaining it. Mid and Tweets are like driving 60 miles an hour down a 50 miles highway and need clean constant power to do so. While a 12" woofer only needs short burts of power like a car does at the dragstrip. Over the long haul the program material will tell which uses more power in the long run but I will say that bass is what eats up dynamic headroom on amps most of the time.

BallinWithNash
11-18-2009, 03:29 PM
Tweeters and Mid Range Drivers will tend to require low but continuous power as they are constantly moving. Bass Drivers will be moving less frequently but require large bursts of power when they do move. So at the end of a 5 minute song, the TOTAL power used by the Tweeters/Mid might have exceeded the Bass driver.

But in most songs there is always bass being played kick drum, bass guitar so wouldn't the bass driver still need continuous power?

BallinWithNash
11-18-2009, 03:30 PM
and thanks guys for the support ... this guy just doesn't seem to get it though haha

harley .guy07
11-18-2009, 03:36 PM
But in most songs there is always bass being played kick drum, bass guitar so wouldn't the bass driver still need continuous power?

I think that what they are trying to say is that midrange and lower treble frequencies are where most of your music is and so clean power is a very important part of producing these frequencies accurately and while there is information in the bass area it does not match the amount of overall music information in the midrange and lower treble frequencies which is arguably the most important area of concern in reproducing music accurately.

BallinWithNash
11-18-2009, 03:40 PM
Thanks, that makes sense now haha i really didn't get it before

harley .guy07
11-18-2009, 03:46 PM
another thing to think about is the people you are refering to. They are car audio people that are probably more concerned about wining a spl contest than overall sound quality of their systems and I have seen a lot of this in my are. They have 4000 watts running 6 subs and have 200 watts running half ass descent mids and highs in their cars and the musical quality of their systems sucks and the only thing they are worried about is trying to be louder than the next guy and E-Stat is right by saying that most of these systems are way heavy on the mid bass for spl reasons and are way overdone and boomy sounding. In fact they even have cds out that take advantage of this boomy midbass to gain higher spl in sound off contests. if you would put a real bands music in there systems they would probably sound like total ass

BallinWithNash
11-18-2009, 03:51 PM
yea i agree completely with that but it doesn't change the fact that it takes more power to produce a lower frequency right? or does it I mean you can EQ the boomy part way up so I guess in that scenario it would be drawing more power then the lower frequencies but if you dont EQ it shouldn't the low frequency require more power?

Mr Peabody
11-18-2009, 05:08 PM
I will have to do some research but I'm thinking the woofer would take more power long term even though the tweeter does move faster. In putting together car and sound reinforcement we've always used larger amps on the bottom end over mids/highs. It definitely takes more power to recreate a bass note.

I'd say 99% of those using big auto audio systems have no idea what good bass response should or does sound like. They are so over driven a bass line or single note is non-existent. It's not the size of the amp but abuse of the gain control. Distortion off the chart.

hermanv
11-18-2009, 05:27 PM
The woofer cone is much smaller than the wavelength being produced (100 Hz is 11 feet ) so the coupling efficiency to the air is very poor. Bass drivers overcome this problem by having larger excursions. You can't see a tweeter move (max excursion of 1mm or 2mm) but a woofer can easily be seen to move for loud low frequency notes (max excursion of 10mm or 20mm typical). So the woofer moves a larger cross section a greater distance or simply put, a lot more air, this takes more power.

RoyY51
11-18-2009, 05:47 PM
When Pix was insisting that it took more power to drive a tweeter than a woofer, I listed several models of powered speakers along with their specs, Without exception, every speaker featured a higher-wattage amp for the woofer and a lower-wattage one for the tweeter. Since Pix never responded, I'm assuming that he came to the conclusion that he (just possibly) might be incorrect.

If you google "bi-amped powered speakers" you'll see what I mean.

BallinWithNash
11-21-2009, 02:20 AM
ok guys how do I prove this ... like legitimately prove this .. is there some math formula's I can use or what?

Geoffcin
11-21-2009, 05:45 AM
If you have a theoretical "perfect" speaker that has a FLAT response from 20hz-20khz. and it's sensitivity (efficiency) is 90dB @ 1 watt. (2.83v) then a 1 watt input of a sine wave at 20hz would make a 90dB sound, and a 1 watt input at 20khz would ALSO make a 90 dB sound.

E-Stat
11-21-2009, 06:25 AM
If you have a theoretical "perfect" speaker that has a FLAT response from 20hz-20khz. and it's sensitivity (efficiency) is 90dB @ 1 watt. (2.83v) then a 1 watt input of a sine wave at 20hz would make a 90dB sound, and a 1 watt input at 20khz would ALSO make a 90 dB sound.
Yet, in the real world such is never the case. Has anyone ever seen a multi-way active speaker where the power of the individual amps increased from low to high?

ATC Monitor (http://www.traveltraxaudio.com/atc/speakers/loudspeakers/professional-monitors/scm200asl-pro.htm)

rw

audio amateur
11-21-2009, 06:55 AM
Yet, in the real world such is never the case. Has anyone ever seen a multi-way active speaker where the power of the individual amps increased from low to high?

ATC Monitor (http://www.traveltraxaudio.com/atc/speakers/loudspeakers/professional-monitors/scm200asl-pro.htm)

rw
Yup, many actively bi/tri/quad amped speakers use more power as you go from the tweet to the bass driver. Cabasse's 'La Sphere' is an example of this.

Mr Peabody
11-21-2009, 06:58 AM
Here's a reference to home subs and the article states your point: http://hometheater.about.com/cs/loudspeakers/a/aasubwoofera.htm

This is about reproducing bass from an instrument and states your point: http://en.wikipedia.org/wiki/Bass_instrument_amplification

Also if anyone heard a lead guitar through 10 watts vs. a bass at 50 watts would not have a problem believing.

This guy seems to have it right: http://everything2.com/title/Subwoofer

States your point, eventually: http://jazztimes.com/articles/21033-power-to-the-people

This gets to the point and is related to car audio: http://hubpages.com/hub/car-speakers

I didn't find a physics lesson but if they can't accept this simple concept I doubt if the physics behind it would do anything. How some one can be into car audio and not understand such a basic principle is beyond me. Do they run 500 watts to the mid/high and 100 to the woofer? They are either yanking your chain or dumber than rocks.

Mr Peabody
11-21-2009, 07:02 AM
You know, maybe you are going about this the wrong way. Present your info and then ask them to find something to prove highs require more power than bass. Once they find that task futile, perhaps they might be convinced.

E-Stat
11-21-2009, 07:08 AM
Yup, many actively bi/tri/quad amped speakers use more power as you go from the tweet to the bass driver. Cabasse's 'La Sphere' is an example of this.
My wording was a bit awkward. What I meant was that as one moves from low to high, have you seen the power output also rise?

The ATC speaker I cited as an example uses five times as much power at the bottom than the top. I have never, for example, seen a speaker using 100 watts on the bottom and five hundred at the top!

rw

audio amateur
11-21-2009, 07:17 AM
My wording was a bit awkward. What I meant was that as one moves from low to high, have you seen the power output also rise?

The ATC speaker I cited as an example uses five times as much power at the bottom than the top. I have never, for example, seen a speaker using 100 watts on the bottom and five hundred at the top!

rw
I'm not sure why you say your wording as awkward, because as far as I am concerned we are both agreeing on the same thing.

E-Stat
11-21-2009, 07:19 AM
I'm not sure why you say your wording as awkward, because as far as I am concerned we are both agreeing on the same thing.
You're right - at first I thought you didn't get my point.

rw

Mr Peabody
11-21-2009, 07:53 AM
AA, are you saying it takes more power for tweeters? If you have some example of that, it's definitely an abnormality because it sure isn't the norm.

BallinWithNash
11-21-2009, 04:40 PM
Haha, thanks Peabody and everyone else for the help. It is much appreciated. And your idea of getting him to find evidence that highs require more power is a good idea .. ill try it.

audio amateur
11-21-2009, 06:16 PM
AA, are you saying it takes more power for tweeters? If you have some example of that, it's definitely an abnormality because it sure isn't the norm.
No no, all the opposite. What exactly, from what I said, makes you two think that? I thought I made myself clear the first time...

Mr Peabody
11-21-2009, 06:56 PM
I misunderstood this statement. But we're all on the same page now, that's what counts :)


Yup, many actively bi/tri/quad amped speakers { use more power as you go from the tweet to the bass driver} . Cabasse's 'La Sphere' is an example of this.

"

audio amateur
11-22-2009, 04:59 AM
Ok cool. Didn't mean to sound offensive but I thought it was quite clear then Estat said that and then you so...
Talking of which if a speaker has a supposedly very flat frequency response (is capable of the lowest octaves, top of the line Dynaudio for example) then how come IT doesn't need more power on the bottom end? (Geoff pointed this out already). Anyone?

E-Stat
11-22-2009, 06:56 AM
Ok cool. Didn't mean to sound offensive but I thought it was quite clear then Estat said that and then you so...
It was all my fault. :)


...then how come IT doesn't need more power on the bottom end? (Geoff pointed this out already). Anyone?
Perhaps you've asked the wrong question. The active monitors I found use lightweight class D amps so perhaps they chose to use one design for both. Unless they are horribly inefficient, one does not usually need 200 watts to drive a tweeter! I found another model (M3) that is a three way using one amp for the woofer and the other for the midrange/tweeter.

rw

Mr Peabody
11-22-2009, 07:29 AM
Dynaudio or any speaker will apply the majority of it's received input power toward the woofers.

Geoffcin
11-22-2009, 12:36 PM
Dynaudio or any speaker will apply the majority of it's received input power toward the woofers.

It does absolutely nothing of the kind.

If you input a watt of power, (say a sine wave) into a Dynaudio, or JMLabs, or Magnepan, the speaker it directs that energy to the driver it is intended for.

Simplified, a low frequency tone it is directed toward the woofer, and the tweeter is blocked from the signal. If it's a high frequency tone, it is directed to the tweeter, and the signal is blocked from the woofer. Obviously there are a myriad of permutations that are possible in a crossover,(slopes/order/phase/ect.) but as I've described it that is the essence of the passive crossover system that is used in the majority of consumer speakers.

I'm surprised Kexodusc hasn't chimed in on this, as crossover theory is something any good DIY guy knows by heart.

While it might SEEM that a woofer is less efficient than a tweeter this is not always the case. Some woofers are very efficient and some tweeters are not. Some designs lend themselves to high efficiency bass response (think horns) some not. A good speaker designer balances the drivers to create a speaker with a flat response that covers the maximum range.

Mr Peabody
11-22-2009, 01:32 PM
Geoffcin it sounds like you are mixing the frequency up with the power. Of course, the crossover seperates the low from high frequencies at the designated points but the woofer will require more power to do it's job than the tweeter.

hermanv
11-22-2009, 02:37 PM
On average tweeters require less power for a given SPL. Crossovers often have resistor attenuators in the tweeter circuit.

It's also important to recognize the difference between perceived level and actual level. White noise (same level at all frequencies) will typically sound bright. Pink noise (decreasing energy vs frequency) will usually sound more like a flat spectrum.

On bi or tri amped systems the woofer driver nearly always get the more powerful amplifier with 10 to 1 not being unusual.

Mr Peabody
11-22-2009, 03:04 PM
Notice in this article where it says the crossover divides the input signal into the frequency range for each driver AND each driver only receives the POWER required for that frequency range. Which means a woofer may require 30 watts of a signal to reproduce a low frequency where the tweeter only needds 1 or less. http://en.wikipedia.org/wiki/Loudspeaker#Loudspeaker_system_design

When we built cabinets using Electro-Voice drivers they had a horn whose power handling was only 5 watts. The overall power handling of the cabinet was massive however. The horn was sold with it's specific module to ensure no more than 5 watts was ever seen by the horn.

Here's a good article in plain language that explains how the crossover is used to limit power as the frequency goes higher. Hence, if a box speaker such as Dynaudio receiver an input signal the woofer WILL receiver the MAJORITY of power. http://www.the12volt.com/caraudio/cross.asp

Additional proof with nice graphs: http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/clipping/page4.html

Geoffcin
11-22-2009, 04:04 PM
Geoffcin it sounds like you are mixing the frequency up with the power. Of course, the crossover seperates the low from high frequencies at the designated points but the woofer will require more power to do it's job than the tweeter.

Rather than argue the point, as it seems to be hard to "prove" any point here, I point you to what any speaker builder would use before choosing a driver, the spec sheet. Take a look at this one;

http://www.madisound.com/catalog/PDF/eton/12-680.pdf

This is a very good woofer, and is flat from 2000Hz all the way down to 100Hz where your engineering skill as a speaker designer would take over with the cabinet design for bass reinforcement.

Matched with a tweeter with a similar sensitivity the final design, say this one;

http://www.madisound.com/catalog/PDF/ST1108.pdf

a 1 watt input at 100Hz in this speaker would produce a SPL of the SAME volume as a 10kHz input signal, there is NO need for more power to the woofer!

According to your theory, this speaker (or all!) would need Eq to be flat, which simply is NOT the case. A speaker that is nominally flat will produce an SPL of the same volume regardless of the signal Hz whether the woofer is producing the tone or the tweeter.

audio amateur
11-22-2009, 04:07 PM
So, according to what you're saying Peabody, crossovers not only filter the frequencies for the specific driver but also the power?? I'm confused...

audio amateur
11-22-2009, 04:09 PM
Perhaps you've asked the wrong question. The active monitors I found use lightweight class D amps so perhaps they chose to use one design for both. Unless they are horribly inefficient, one does not usually need 200 watts to drive a tweeter! I found another model (M3) that is a three way using one amp for the woofer and the other for the midrange/tweeter.

rw
I'm not talking about active speakers now but normal passive speakers.

Geoffcin
11-22-2009, 04:26 PM
On average tweeters require less power for a given SPL. Crossovers often have resistor attenuators in the tweeter circuit.

It's also important to recognize the difference between perceived level and actual level. White noise (same level at all frequencies) will typically sound bright. Pink noise (decreasing energy vs frequency) will usually sound more like a flat spectrum.

On bi or tri amped systems the woofer driver nearly always get the more powerful amplifier with 10 to 1 not being unusual.

Most crossovers are designed with inductors and capacitors. A crossover is a FILTER system, not an eq system. Resistors are only used with non-matching components, and they do NOT eq. the speaker other than to match components overall output.

Woofers are by nature able to handle more power by virtue of being larger and able to dissipate more heat. Also, even though you can put a 10X more powerful amp on a woofer, that does NOT mean that the woofer would actually NEED 10x more power to create the same SPL.

Mr Peabody
11-22-2009, 04:30 PM
Geoffcin, I refer you to the links I posted. The original point of the thread was whether it takes more power to reproduce lower frequencies and in fact it does. The crossover not only directs the various frequencies to the drivers but it also disperses the needed power. The higher the frequency the less power needed, the less power directed that way.

If you mic the speaker's output from the front you may see what you are talking about a quasi flat response but internally that woofer will use way more of the input POWER than the tweeter.

Mr Peabody
11-22-2009, 04:45 PM
AA, please read the links I posted in earlier post, it will explain better than I can. The crossover does not "filter" power. By the size of the coils and caps as it relates to frequency directs the power, the power reduces as the frequency goes higher.

G, not sure really what tangent you are off on, no one said anything about a speaker EQ'ing. You have a set input power to a speaker, via what I stated to AA the majority of that said power will go to the woofer. Reason being the woofer requires way more power to reproduce low frequencies than a tweeter does to reproduce highs. Perhaps it will make more sense if you read from the links I posted.

Geoffcin
11-22-2009, 04:52 PM
I don't claim to be an expert on the subject, but I can tell you that a woofer that produces a 90dB SPL from 1 watt at 100Hz uses the same energy as a tweeter that produces that same SPL from 1 watt at 10kHz. The woofer doesn't NEED more power, nor does a crossover somehow redirects power to it other than filter out the frequencies that were not intended for it.

audio amateur
11-22-2009, 05:03 PM
P, I've had a look at the links and from what I've read it just talks about filters and filtering frequencies to the different drivers.

I've always thought like Geoff but I'm having doubts now. Why do active speakers use more power on the bass if there is no need for it? Unless the woofers they use are less efficient than their tweeters and thus require more gain (power) on the woofs.

Geoffcin
11-22-2009, 05:14 PM
P, I've had a look at the links and from what I've read it just talks about filters and filtering frequencies to the different drivers.

I've always thought like Geoff but I'm having doubts now. Why do active speakers use more power on the bass if there is no need for it? Unless the woofers they use are less efficient than their tweeters and thus require more gain (power) on the woofs.

The main reason for active speakers using more power on the woofers is that they can. By actively eq'ing the woofer and applying more power, you can use a smaller woofer and a smaller enclosure to produce the same bass. You can also eq for a flatter response. This is exactly what Axiom does with their subs, and from the one I reviewed this technology works superbly.

harley .guy07
11-22-2009, 05:44 PM
the only thing that I will add is the simple structures of speaker drivers. In what I have seen and worked with a woofer with a 3 inch woice coil driving an 8 inch cone from a magnet that has a 150 ounce stucture(this is all for example reasons) will take more electromagnetic force than a 1 inch soft dome tweeter with a 1 inch coice coil and neo magnet. The reason why some of your smaller subwoofers use higher power amps is because of the stiffer cone material, longer xmax(throw), and higher power handling motor structure of the woofer. this is to try to maximize what a woofer of that size would normally do. And for the most part it works with the exception of overall spl output at the lowest of frequencies.

But my main thing is to concider the motor structure of a woofer driving a cone that is that big in diameter and tell me that this will not take more power than a tweeter with a motor structure that is under half the size of the woofer besides the fact that it is driving a dome or cone that is 1/8 to 1/12 the woofers size. I am just thinking about the electromagnetic force needed to move examples of each of these drivers and thinking there is no way the tweeter would need as much electromagnetic force to move it as the woofer. Thats what i have always believed and it makes sense. look at most peoples systems. 500 to 1000 watt amps driving powered subs of 12 to 15 inches in diameter with 2 1/2 to 4 inch voice coils and huge magnet structures. And in that same system they have 150 to 200 watts per channel running tower speakers with midwoofers and tweeters. not to say there are not exceptions but it will be hard for me to believe that the points I have made don't make sense.

Mr Peabody
11-22-2009, 05:46 PM
AA, did you see this link from my earlier post? I don't know how much more simpler it could be: http://www.the12volt.com/caraudio/cross.asp

G, if a bass note requires equal power as a high note show me some proof as you are defying physics.

harley .guy07
11-22-2009, 06:07 PM
Mr. Peabody I did read this and that was a more technical way of saying what I just posted. the though of a tweeters dome and motor structure in comparison to a woofers cone and motor structure plus the other elements it would be crazy to think that it takes as much power to run a tweeter than a woofer. Put a chevy small block with 325 horse power in a nova and it will be pretty quick do to the fact of the power to weight ratio. Put that same motor in a big cady and it will not perform the same, more power will be needed. Woofers are bigger structures and even though woofers get shorter bursts of power from kick drums and bass guitar and tweeters get more constant music energy it would be crazy to think that tweeters would take the same amount of power to run as bigger woofers.

Mr Peabody
11-22-2009, 06:27 PM
Mr. Peabody I did read this and that was a more technical way of saying what I just posted. the though of a tweeters dome and motor structure in comparison to a woofers cone and motor structure plus the other elements it would be crazy to think that it takes as much power to run a tweeter than a woofer. Put a chevy small block with 325 horse power in a nova and it will be pretty quick do to the fact of the power to weight ratio. Put that same motor in a big cady and it will not perform the same, more power will be needed. Woofers are bigger structures and even though woofers get shorter bursts of power from kick drums and bass guitar and tweeters get more constant music energy it would be crazy to think that tweeters would take the same amount of power to run as bigger woofers.

Yeah, but since I pulled it from an earlier post I said it first, so there. :) Just messing with you.

Aside from the woofer needing more power the post also shows how the crossover distributes the power based on frequency. In addition, to not believing woofers require more power, Geoffcin believes the woofers and tweeters receive the same amount of power from a speaker input signal.

Geoffcin
11-22-2009, 06:42 PM
Yeah, but since I pulled it from an earlier post I said it first, so there. :) Just messing with you.

Aside from the woofer needing more power the post also shows how the crossover distributes the power based on frequency. In addition, to not believing woofers require more power, Geoffcin believes the woofers and tweeters receive the same amount of power from a speaker input signal.

Please do not misquote me, as that's not what I've said.

harley .guy07
11-22-2009, 06:46 PM
He seems to not realize the effects that impedance plays on power output. Or in lamens terms RESISTANCE. that is that main factor that determines how much power any given driver gets and the impedance is different at any given frequency and bass is usually were the lower impedance's are so thats where alot of the power goes which is a good thing since some of todays woofers and subwoofers have very stiff cone structures for rigity,huge magnets and voice coils in excess of 5 inch's in some cases. The motor structure and cone stiffness and xmax(throw) are all indicators of how much power they can handle and how sensitive a woofer will be. I think You and me Mr. peabody have made are argument strong and with proven backup literature. I think the judges hammer just hit the damn table on this one

Mr Peabody
11-22-2009, 07:16 PM
Here's one other article I ran across, see where they begin to talk about "Power Usage" http://www.colomar.com/Shavano/general_sound_info.html

audio amateur
11-23-2009, 04:19 AM
Mr P., in that article, all they are saying is explaining how a filter works, how a 12dB octave filter for example will bring down the dB or power by 12 dB every octave. This is NOT saying anything about one driver or the other generally using more power. They both could be using the same amount of power for all we know, according to the link you've posted.
If you're not agreeing here, then you should perhaps copy & paste the relevant literature as I cannot seem to find it.

Where is EStat?!

poppachubby
11-23-2009, 04:30 AM
I have had some speaker work done lately. Because of this I have been hanging around a speaker tech. Just yesterday, he was explaining this to me.

I have no "proof" but I would say this guy is qualified to make a call. I also had no idea what this thread was about until reading it just now.

We were discussing speakers and the power required to drive them. He said the bigger the speaker/magnet, the easier they are to drive or push sound through. Tweeters would require more power. I forget his exact explanation but it had to do with the process between the coil and the magnet.

I'll ask him again today and type what he says onto this thread.

We were talking details based on the fact that I want super efficient speakers for my tube amp. He basically told me something with a large 10 or 12 will generally be more efficient than something with a couple of smaller 6.5's or 8's.

I think that horns also play into this theory. Have you ever seen a horn on a big woofer? The horn is there to help convey the sound and help with the efficiency of the tweeters power issue.

Anyhow, I'm no expert and I may have a couple of details wrong but the overall point has been made correctly. I'm afraid that Geoffcin seems to be most correct about this matter. I haven't looked at any reference material posted to the thread. I'm pretty confident I don't need to. This tech I speak of has been at it for years and I fully trust what he has to say.

poppachubby
11-23-2009, 04:35 AM
Oh and to the OP, I think the point of "more power to a lower or higher note" is moot. It doesn't have to do with notes or frequencies. It has to do with physical structures of the speakers and their relative conductivity based on the magnets they use. Sound reproduction is an electrical process, it doesn't care about low or high.

This is my assumption based on what I've been told. Someone show me otherwise.

audio amateur
11-23-2009, 04:37 AM
Interesting.
Chubbs, I'm online

poppachubby
11-23-2009, 04:48 AM
AA, been having issue with Messenger. One sec I am going to try and upgrade my version

Geoffcin
11-23-2009, 05:00 AM
Oh and to the OP, I think the point of "more power to a lower or higher note" is moot. It doesn't have to do with notes or frequencies. It has to do with physical structures of the speakers and their relative conductivity based on the magnets they use. Sound reproduction is an electrical process, it doesn't care about low or high.

This is my assumption based on what I've been told. Someone show me otherwise.
Hi Poppa,

Very perceptive! Sound reproduction is a electro-mechanical process and as such follows strict conservation of energy rules. Basically with modern loudspeakers an electrical signal is sent to a driver which moves a diaphragm of some type to move air. Driver sensitivity is based on many factors, and it's quite true that as the frequency gets lower you need a larger and larger structure to move air efficiantly, however you don't need more power to produce the same SPL with drivers of the same efficiency.

Mr Peabody
11-23-2009, 03:01 PM
You all are so wrong. Geoffcin you are mixing up your concepts. So what if the tweeter and woofer are the same sensitivity, it will still take the woofer more power to reproduce the 90 dB than a tweeter.

AA, you said it yourself, the power REDUCES as the frequency goes up, hello....., that's what we are talking about. If the power reduces as you approach 20 kHz, then it takes less power at higher frequencies.

G, you state what you think but have yet to show anything in writing. How can an engineer not understand simple mass?

Poppa, you are just confusing things more. When have you ever seen more, or even, the same power go to a tweeter? Not in car audio, not in pro audio and not in a box speaker.

Geoffcin
11-23-2009, 03:18 PM
OY?! 1 watt is one watt! If a speaker produces a 50Hz tone at 90dB with ONE WATT using the woofer, and a 10kHz tone of 90dB using ONE WATT with it's tweeter, then it's using the SAME amount of energy to produce either tone.

Futhermore, the flatter the responce of a speaker, the more equal the power requirement to produce sound across a wider range of the spectrum. The theoretical "perfect speaker" would produce a tone of equal SPL across the entire range of human hearing using the SAME amount of energy no matter what the frequency.

audio amateur
11-23-2009, 03:52 PM
AA, you said it yourself, the power REDUCES as the frequency goes up, hello....., that's what we are talking about. If the power reduces as you approach 20 kHz, then it takes less power at higher frequencies.

.
Okay, but again you are simply pointing out the obvious job of a filter. As you say, the power reduces as the frequency goes up (low pass filter). BUT, it also reduces as the frequency goes down (high pass filter).
We still haven't achieved anything here :mad2:

poppachubby
11-23-2009, 04:10 PM
Poppa, you are just confusing things more.

No, not really. I think it was pretty confused before my comments.

Mr Peabody
11-23-2009, 05:40 PM
AA, you need to read the articles posted more thoroughly. It took me time to find them and I don't have time to spoon feed any one.

Please notice, EVERYONE, in this next article where the writer states FOR EVERY OCTAVE LOWER YOU GO IT TAKES 4 TIMES THE EXCURSION AND 16 TIMES THE POWER.

http://sound.westhost.com/linkwitz-transform.htm

OY, I'd say.

BallinWithNash
11-23-2009, 05:58 PM
Ok I'm going to be on Peabody's side for this one,
"Bass notes move a lot more air than treble notes. They are more of an engineering challenge to recreate. There is an inverse cube law in effect - a 30Hz note at 100dB represents 8 times as much acoustical energy as a 60Hz note at 100dB. There is also the issue that most systems use two normal speakers for stereo, but only one sub. Therefore, to go an octave lower than your main speakers, the subwoofer will ideally be 16 times larger than the main speakers. The more extension a sub attempts, the larger this number will get.

In the real world, very few people are willing to live with such an enormous speaker. Subs are scaled down, and are therefore a lot less efficient than the main speakers. Thus, the average sub needs to burn a lot more power than a normal speaker. The smaller the sub is, the higher the required power.

Since the surface area of the driver is unlikely to be 16 times the surface area of the main woofers, the sub's cone will also be required to move a lot further to generate equivalent SPL. Again, the smaller the driver is, the greater the excursion requiremed to match the main speakers.

The outcome of all this compromise is that the sub works a lot harder than the main speakers. They work differently, and they *sound* different. This is more or less noticable depending on how much the design is compromised, how it is implemented, and how much money is thrown at the problem." Courtesy of some guy way smarter then me in this article that Peabody posted earlier http://everything2.com/title/Subwoofer .... this guy seems to be correct to me.

Geoffcin
11-23-2009, 05:59 PM
AA, you need to read the articles posted more thoroughly. It took me time to find them and I don't have time to spoon feed any one.

Please notice, EVERYONE, in this next article where the writer states FOR EVERY OCTAVE LOWER YOU GO IT TAKES 4 TIMES THE EXCURSION AND 16 TIMES THE POWER.

http://sound.westhost.com/linkwitz-transform.htm

OY, I'd say.

Time to give it up Peabo. If you actually READ the article you would see that the author is describing what the Linkwitz transform circuit would require to eq the speaker so it can perform past it's nominal rating. ANY speaker driver eq'ed to produce 3dB more than it is nominally rated for will require DOUBLE the power to perform the task. This goes for woofers AND tweeters. You can perform the same type of eq going HIGHER in frequency and you would require the same amount of extra energy to perform it.

Geoffcin
11-23-2009, 06:07 PM
Ok I'm going to be on Peabody's side for this one,
"Bass notes move a lot more air than treble notes. They are more of an engineering challenge to recreate. There is an inverse cube law in effect - a 30Hz note at 100dB represents 8 times as much acoustical energy as a 60Hz note at 100dB.


You may be with him, but you would be wrong. The measure Decibel, or dB is a measure of sound pressure energy. (in this example) A 100dB sound has the same energy whether it's a 20Hz note or an inaudible ultra-high frequency 100Khz note.

Y

BallinWithNash
11-23-2009, 06:14 PM
You may be with him, but you would be wrong. The measure Decibel, or dB is a measure of sound pressure energy. A 100dB sound has the same energy whether it's a 20Hz note or an inaudible ultra-high frequency 100Khz note.

Y

Prove it ... every one I know has a bigger amp for there sub if it is not needed why spend the extra money? You yourself have subs being powered by a 250 watt amp and your PS Audio HCA-2 amp only puts out 150 I want you to take the HCA and hook it up to your subs and then take a 250 watt amp and hook it up to your midrange/tweeters and turn it up ... the bigger amp will have no problem powering the mid/highs but that small amp will start clipping faster then the 250 watt amp especially if it is power the subs ... now if you switch them back around everything will work fine and nothing should clip till the volume level gets way up there.

Geoffcin
11-23-2009, 06:29 PM
Prove it ... .

Sorry, but I am getting a bit tired trying to teach basic engineering principles to people who don't want to believe it. A dB is something that every engineering freshman gets beaten into his head, and it's something that you should have tried to understand before posting your last post.

BallinWithNash
11-23-2009, 06:40 PM
bud if it is a the same SPL it will take more power to produce a lower frequency versus a high frequency I love people who call bull **** and dont back it up ... every active speaker has a bigger amp for the woofer everyone I have met even you have a bigger amp for your subs ... explain to me why if it is not needed? again you just keep saying we are wrong with no facts

Mr Peabody
11-23-2009, 06:41 PM
Why, should be something you answer Geoff. You've given us nothing but talk with no proof. Maybe you should go back and read the original post, I've supplied ample information to show my point, I'm waiting on yours. I don't think that's too much to ask since you are trying to go against the majority of the audio world.

Geoffcin
11-23-2009, 07:02 PM
bud if it is a the same SPL it will take more power to produce a lower frequency versus a high frequency I love people who call bull **** and dont back it up ... every active speaker has a bigger amp for the woofer everyone I have met even you have a bigger amp for your subs ... explain to me why if it is not needed? again you just keep saying we are wrong with no facts

If your sub has a a rating of 90dB per watt at 32Hz then 1 watt will produce what you would THINK is a super-powerful 90dB 32Hz shaking, but it's really no louder (powerful) than a 90dB 1kHz tone that your main speaker produces. The reason you THINK it's more powerful is that a 32Hz wave couples to your body rather well and you will FEEL it, as opposed to the 1kHz sound which you will only hear. The operative thing here is that you THINK it's more powerful. That's not science, it's guessing via intuition.

Most subs are NOT that efficient (although my 15" Velodynes are) with some of the smaller ones having terrible ratings which require them to have massive amps to produce the same SPL as larger more efficient subs. Velodyne makes an 8" sub with a 1000 watt amp so it can produce higher SPL levels. Remember, for every 3dB increase it requires TWICE the power, so if the sub starts out with an efficiency of 78dB per watt at 32Hz it will need LOTS of power to produce a 90dB SPL.

BallinWithNash
11-23-2009, 07:03 PM
Time to give it up Peabo. If you actually READ the article you would see that the author is describing what the Linkwitz transform circuit would require to eq the speaker so it can perform past it's nominal rating. ANY speaker driver eq'ed to produce 3dB more than it is nominally rated for will require DOUBLE the power to perform the task. This goes for woofers AND tweeters. You can perform the same type of eq going HIGHER in frequency and you would require the same amount of extra energy to perform it.

Well yes, but that is a sub woofer playing a 90HZ note has a wave length of 3.3310e+6 meters versus a tweeter playing a 100000Hz note has a wave length of 2.9979e+3 ... those two wave lengths are different so wouldn't it take more power to reproduce the longer wave length?

And on the other note why do we have subs, tweeters, and midrange speakers if each speaker can handle everything? there would be no point to buy a larger amp for a sub?

Geoffcin
11-23-2009, 07:16 PM
Why, should be something you answer Geoff. You've given us nothing but talk with no proof. Maybe you should go back and read the original post, I've supplied ample information to show my point, I'm waiting on yours. I don't think that's too much to ask since you are trying to go against the majority of the audio world.

No, you've posted a lot of stuff that you don't understand, or have totally misinterpreted. I'm not going to go out and search the web to dig up things to impress you. Why, so you can then tell me that you have a different view of what a decibel really is? Like that's something that is debatable?!

The sad facts are that a lot of what I've read in this post amount to audio superstition. Besides a degree in engineering, I have a minor in anthropology, and I can tell you that superstition is something that is about as hard to get through as reinforced concrete. I'm not going to bother trying anymore. What I've written so far will have to suffice. You can believe it or not. It is your choice.

BallinWithNash
11-23-2009, 07:23 PM
And again no one has explained why you buy a more powerful amp for you sub?????:confused5::mad2: :frown2: :nono: :dita: :prrr: :sleep:

BallinWithNash
11-23-2009, 07:25 PM
No, you've posted a lot of stuff that you don't understand, or have totally misinterpreted. I'm not going to go out and search the web to dig up things to impress you. Why, so you can then tell me that you have a different view of what a decibel really is? Like that's something that is debatable?!

The sad facts are that a lot of what I've read in this post amount to audio superstition. Besides a degree in engineering, I have a minor in anthropology, and I can tell you that superstition is something that is about as hard to get through as reinforced concrete. I'm not going to bother trying anymore. What I've written so far will have to suffice. You can believe it or not. It is your choice.

That sounds like the words of a loser.

BallinWithNash
11-23-2009, 07:27 PM
http://www.youtube.com/watch?v=_QyYaPWasos ... hehe:2: :18: :7: :0:

harley .guy07
11-23-2009, 07:31 PM
Mr. Peabody I would love to help you continue to back your point but it is getting to the point of a pissing match and I know that the bigger the motor structure and driver the more power needed to drive it to it limits and that is what it is. Its electromagnetic reality. I'm done

Geoffcin
11-23-2009, 07:35 PM
Well yes, but that is a sub woofer playing a 90HZ note has a wave length of 3.3310e+6 meters versus a tweeter playing a 100000Hz note has a wave length of 2.9979e+3 ... those two wave lengths are different so wouldn't it take more power to reproduce the longer wave length?

And on the other note why do we have subs, tweeters, and midrange speakers if each speaker can handle everything? there would be no point to buy a larger amp for a sub?

No it would not. Longer waves do not mean more power.

All drivers have good and bad attributes. You choose a driver based on what job (frequency) you want to to do, and how well it will work in your design. Midrange speakers are often very efficient into the treble, but they beam when the wave goes below their diameter. They also breakup when the frequency goes past what they were designed for. Woofers have the same type of problem into the midrange. Tweeters are very inefficient into the bass, so it pays to design your speaker with multiple drivers to take advantage of the good attributes of them, and to minimize the bad ones.

BallinWithNash
11-23-2009, 07:39 PM
How do longer waves not mean more power if you had a 30 sec sine wav and a 10 sec sine wav which would take more power to produce? ... well the 30 sec one would because its longer the amp's would be playing music longer.

Geoffcin
11-23-2009, 07:42 PM
Mr. Peabody I would love to help you continue to back your point but it is getting to the point of a pissing match and I know that the bigger the motor structure and driver the more power needed to drive it to it limits and that is what it is. Its electromagnetic reality. I'm done

Actually the larger and more powerful the magnet structure of the driver the MORE efficient it is. This is another case of "audio superstition" based on what you think it SHOULD be by comparing audio drivers to chevy small blocks.

Geoffcin
11-23-2009, 07:50 PM
How do longer waves not mean more power if you had a 30 sec sine wav and a 10 sec sine wav which would take more power to produce? ... well the 30 sec one would because its longer the amp's would be playing music longer.

Are you for real?

Do you really not know the difference between measuring the length of a wave in meters or in seconds?

BallinWithNash
11-23-2009, 07:52 PM
haha i know i was just seeing you would catch it hehe and i thought the bigger it is the more resistance it has ... i dont know on this one that's just what i though so correct me on this one, please and again why DO WE BUY BIGGER AMPLIFIERS FOR SUBS???

poppachubby
11-23-2009, 07:53 PM
How do longer waves not mean more power if you had a 30 sec sine wav and a 10 sec sine wav which would take more power to produce? ... well the 30 sec one would because its longer the amp's would be playing music longer.


Hahahahha, you were doin pretty good until this nugget!! That's gold...

Mr Peabody
11-23-2009, 07:54 PM
Geoff, I really didn't think you would as you've brought up several irrelevant topics to the original question posed. The articles I posted for the most part covered a lot of ground, i was willing to post them but not willing to cherry pick the relevant points out. Each one had specific information to show it takes more power to reproduce bass than higher frequencies. If you aren't willing to show otherwise then so be it. If what you were saying is true then it would have showed up in my searches.

I can understand your frustration but, superstition? Please

BallinWithNash
11-23-2009, 07:58 PM
Hahahahha, you were doin pretty good until this nugget!! That's gold...



yea i thought so too ... my mind is at other places right now im trying to figure out how to get a new circuit board in my xbox ... with out voiding the warranty ... off topic any how yea my bad haha

Geoffcin
11-23-2009, 08:00 PM
haha i know i was just seeing you would catch it hehe and i thought the bigger it is the more resistance it has ... i dont know on this one that's just what i though so correct me on this one, please and again why DO WE BUY BIGGER AMPLIFIERS FOR SUBS???

OK, the reason we buy larger amps for subs is because for the most part subs are much more INEFFICIENT than loudspeakers over the frequency range that they cover. So, if your sub has a 80dB efficiency over it's range, say 30Hz-100Hz, and your main speaker is 89dB over it's range, to match the main speaker correctly you would need SIX times the power.

HOWEVER, if you had a sub that DID have the same efficiency as your main speaker, then 1 watt of input energy would make the same SPL as the main even though the frequency was lower.

Anyway, that's it for me tonight. Hope everyone had fun!

BallinWithNash
11-23-2009, 08:03 PM
OK, the reason we buy larger amps for subs is because for the most part subs are much more INEFFICIENT than loudspeakers over the frequency range that they cover. So, if your sub has a 80dB efficiency over it's range, say 30Hz-100Hz, and your main speaker is 89dB over it's range, to match the main speaker correctly you would need SIX times the power.

HOWEVER, if you had a sub that DID have the same efficiency as your main speaker, then 1 watt of input energy would make the same SPL as the main even though the frequency was lower.

Anyway, that's it for me tonight. Hope everyone had fun!

So your saying if someone made the "perfect" speaker it would be the same but since know one has done that yet ....... me and pea are right?

Geoffcin
11-23-2009, 08:08 PM
So your saying if someone made the "perfect" speaker it would be the same but since know one has done that yet ....... me and pea are right?

Actually I have made the perfect speaker, but because you and pea busted my stones you aren't invited over to hear it! :hand:

BallinWithNash
11-23-2009, 08:10 PM
Actually I have made the perfect speaker, but because you and pea busted my stones you aren't invited over to hear it! :hand:
Luckily I can back trace your IP address hahaha ... way to much work though I am happy with what I got .... and so basically when it comes down to it we are both right it just depends on the setting?

Geoffcin
11-23-2009, 08:16 PM
Luckily I can back trace your IP address hahaha ... way to much work though I am happy with what I got .... and so basically when it comes down to it we are both right it just depends on the setting?
No actually I am always right, unless of course your talking about when hell freezes over and then you would be too. :devil:

BallinWithNash
11-23-2009, 08:18 PM
I'm not going to lie so confused right now, I have no clue what just happened haha and i could very easily back trace your ip to your zip code

BallinWithNash
11-23-2009, 08:22 PM
and im pretty sure you didnt make the perfect speaker or you would be filthy rich and not talking to me and arguing about it haha

harley .guy07
11-23-2009, 08:35 PM
the next time you are at a live music venue ask the sound guy what he is powering his mid and high stage speakers and his woofer cabinets with and see which one it using a higher power amp. The sensetivity of given driver is what one watt will produce with this driver but try to tell me a run of the mill 10 inch woofer with a xmax of around 5mm with a sensetivity of 90 db with a 60 ounce magnet, 2 inch voice coil and mildly rigid paper cone and a 10 inch woofer with an xmax of around 12.5mm and a motor structure with a 4 inch voice coil and a 190 ounce magnet with a much stiffer cone structure with also 90 db efficiency will put out the same amount of sound at 1 watt but it will certainly take more power to take the longer excursion woofer to its limits than the run of the mill woofer. My point is that sensitivity is measured at 1 watt, but thats not the say that it will not take more power for a higher compliance woofer than a lower end unit. just a point and thats it

BallinWithNash
11-23-2009, 08:43 PM
Yes go harley i think we took the lead again haha

harley .guy07
11-23-2009, 08:44 PM
well being insulted about the chevy small block thing cracks me up because you are at a point that you have to insult someone to make your point. That is a sign that your points are not justified and you are trying to just be bullish in your comments and that is not needed what so ever. I have been around home sound and pro sound for many years and the last thing I would so is try to insult someone I would just try to make your point and not worry so much about what others say. And if you made the perfect speaker then for damn sure I would have would heard about it know.

harley .guy07
11-23-2009, 08:51 PM
And another point. With human hearing being as varying in its perception of sound there is no such thing as the perfect speaker. Every persons perception of sound is different and the whole concept of the perfect speaker would make most of us crack up, there are too many variables in this to say that one person has made the perfect speaker. For you maybe but not for everyone else with different ears and concepts of what that "perfect sound" is

harley .guy07
11-23-2009, 08:56 PM
Hahahahha, you were doin pretty good until this nugget!! That's gold...

Actually the whole concept of stiffening capacitors in amplifiers are for dynamic peaks. A long sine wave at 30 hertz at high volumes would be a dynamic peak would it not. that is why more power is needed for those type of peaks. It might be different than discribed above but it still is a a peak non the less.

hermanv
11-23-2009, 09:21 PM
Most crossovers are designed with inductors and capacitors. A crossover is a FILTER system, not an eq system. Resistors are only used with non-matching components, and they do NOT eq. the speaker other than to match components overall output..
This is simply untrue. Crossovers are used to match levels as well a filter frequencies. L's and C's for frequency and R's for level or Q. The 3 way crossover my friend and I designed contains 9 resistors.

Watch out, many speakers are rated at 2.83 VRMS which does happen to be 1 Watt at 8 Ohms. If this how they are rated then speaker impedance does in fact enter into the question.

Last but not least is program content, most of us do not listen to white noise. Much recorded music contains more bass energy.

Please stop speaking in absolutes the question is more complex than that.

audio amateur
11-24-2009, 03:32 AM
Wow, I think I'm late to the party!

Fortunately Geoff has already said what I want I have to say about the topic.

Geoffcin
11-24-2009, 04:55 AM
This is simply untrue. Crossovers are used to match levels as well a filter frequencies. L's and C's for frequency and R's for level or Q. The 3 way crossover my friend and I designed contains 9 resistors.

Watch out, many speakers are rated at 2.83 VRMS which does happen to be 1 Watt at 8 Ohms. If this how they are rated then speaker impedance does in fact enter into the question.

Last but not least is program content, most of us do not listen to white noise. Much recorded music contains more bass energy.

Please stop speaking in absolutes the question is more complex than that.

Yes, your correct. A resistor would be used to match the separate drivers, and in a rudiment way it would provide passive eq, but that would be across all the frequency that the specific driver would cover. A more sophisticated Linkwitz transform circuit would be required if you want to ramp the eq up as the driver's efficiency goes down. (independent of frequency direction) But then you would need a dedicated amp, and for the basis of simplicity we were talking about passive circuitry.

No, of course we don't listen to white noise, but a good speaker designer shoots for as flat a response from his design as possible.

Absolutes are what basic physics is all about. A dB of sound energy is a dB of sound energy whether it's 20Hz, or 20kHz. They have the same intrinsic power. If a driver is less efficent then it's going to take more input power to create the same SPL. The laws are well known and are indisputable even if people want to believe otherwise.

Geoffcin
11-24-2009, 05:12 AM
well being insulted about the chevy small block thing cracks me up because you are at a point that you have to insult someone to make your point. That is a sign that your points are not justified and you are trying to just be bullish in your comments and that is not needed what so ever. I have been around home sound and pro sound for many years and the last thing I would so is try to insult someone I would just try to make your point and not worry so much about what others say. And if you made the perfect speaker then for damn sure I would have would heard about it know.
Hey dude, it wasn't an insult, and I'm sorry if you took it as such. I just was trying to point out that they are different things totally and as such not good for a comparison. Actually the Chevy small block is MUCH more efficient than any speaker, so perhaps we should switch to internal combustion if we really want to design a better speaker...:3:

A good sound guy wants a balanced sound so you can hear everyone playing. He's got to know his equipment, and it's efficiencies and balance them correctly. I was close friends with a local band when I back in school. They started to play larger and larger clubs, and had to rent big sound gear to do them. For one of the larger venues they rented a massive horn loaded bass reinforcement cab. I thought for sure that this massive cab would take 1000's of watts to drive, but the rating was for 500 watts max, and a SPL of 109dB for 1 watt! As I remember they hooked it up to a 200w amp and the thing would quite literally blow people down at 6ft!

poppachubby
11-24-2009, 05:17 AM
Ya, I haven't talked to my tech friend yet. I think I am going to look online to try to solve this mystery. It seems strange that we are all so split on what should be a cut and dry topic.

I will say again, it takes less power to drive a larger speaker. It's just that simple.

02audionoob
11-24-2009, 06:24 AM
I will say again, it takes less power to drive a larger speaker. It's just that simple.

I thought the topic is whether more power is required in producing a high note than a low note. If you want to say it would require more power to get a given amount of sound out of a 6-inch woofer than it would to get that much sound out of an 8-inch woofer of the otherwise exact same design, I'll buy that. This topic looks like it has more variables than that, though.

poppachubby
11-24-2009, 06:42 AM
I thought the topic is whether more power is required in producing a high note than a low note. If you want to say it would require more power to get a given amount of sound out of a 6-inch woofer than it would to get that much sound out of an 8-inch woofer of the otherwise exact same design, I'll buy that. This topic looks like it has more variables than that, though.

This is however, the root of the issue. Before any freq. is considered, we must look at the basic electrical process that allows any freq. to be emitted at all. Now, if it takes more power to drive a smaller speaker or for our discussion, tweeter, surely that lends to the argument regarding frequencies.

02audionoob
11-24-2009, 07:02 AM
This is however, the root of the issue. Before any freq. is considered, we must look at the basic electrical process that allows any freq. to be emitted at all. Now, if it takes more power to drive a smaller speaker or for our discussion, tweeter, surely that lends to the argument regarding frequencies.

I honestly don't see the connection. With the comparison of two woofer sizes, we're talking about getting the same sound out of two speakers. The original topic is about two different sounds.

poppachubby
11-24-2009, 10:08 AM
No, it can lend to two different frequencies noob, the first principle of power dispersion will govern the frequency principle. Dude are you coming online or what? At the very least come on so we can split hairs....

E-Stat
11-24-2009, 10:08 AM
A dB of sound energy is a dB of sound energy whether it's 20Hz, or 20kHz. They have the same intrinsic power.
The discussion has seemed to have drifted from the original question: "So in other words the lower the note the more power or the higher the note the more power?"

You refer to a resulting output, not what is required to achieve that. Can you find an example of a multi-way active speaker that uses a higher powered amplifier for the tweeter than for the woofer? The overwhelming number I find, including a Braun unit I once had, use typically about twice as much power for the low frequencies than the high frequencies to achieve an output that is level balanced.

rw

GMichael
11-24-2009, 10:18 AM
Has anyone ever heard a tweeter clip? Or draw so much power that it makes your lights dim?

E-Stat
11-24-2009, 10:32 AM
Has anyone ever heard a tweeter clip? Or draw so much power that it makes your lights dim?
Strictly speaking, clipping is a characteristic of an amplification stage not a driver. It is when the driven signal shape appears "clipped" or flattened out due to overload. Can tweeters be over driven? Absolutely. While the failure mode usually doesn't include over-excursion as you can find in a woofer, their voice coils can be fried. That is the reason behind using ferrofluid damping.

rw

GMichael
11-24-2009, 10:46 AM
Strictly speaking, clipping is a characteristic of an amplification stage not a driver. It is when the driven signal shape appears "clipped" or flattened out due to overload. Can tweeters be over driven? Absolutely. While the failure mode usually doesn't include over-excursion as you can find in a woofer, their voice coils can be fried. That is the reason behind using ferrofluid damping.

rw

I think you are saying what I meant to say. Has a tweeter ever drawn so much power that the amp clips?
As far as overdriving a tweeter, I am painfully aware of that. Remember the whole blowing the tweeters out of my 3 week old speakers a few years back? Those darn test tones!

Geoffcin
11-24-2009, 11:20 AM
The discussion has seemed to have drifted from the original question: "So in other words the lower the note the more power or the higher the note the more power?"

You refer to a resulting output, not what is required to achieve that. Can you find an example of a multi-way active speaker that uses a higher powered amplifier for the tweeter than for the woofer?
rw

And you always will. Unless of course you want to live with speakers the size of the Majestic 945, which is flat down to ~25Hz or so. Nowhere have I said that woofers and tweeters ALWAYS have equivalent efficiency. Most don't. However if they did, then one watt of input would equate to the same SPL no matter what the frequency.

E-Stat
11-24-2009, 11:33 AM
And you always will.
Perhaps that is the answer to the original question posed by the car stereo guy.

rw

Geoffcin
11-24-2009, 11:37 AM
I think you are saying what I meant to say. Has a tweeter ever drawn so much power that the amp clips?
the tweeters out of my 3 week old speakers a few years back? Those darn test tones!

I would say yes absolutely, because I've done it!

Back when I got my (then new) Alpha 9 CD player I hooked it up and played Pink Floyd's "Time". For those who don't know the song the beginning starts off quietly and then dozens of alarm clocks start going off. I set the volume on my pre amp to what I thought was a pretty decent level and than sat back down. What I didn't count on what the Arcam CD player had a good 50% more output than my old CD player. When the alarm clocks cam in the sound was deafening, and then, before I could get up one tweeter and then to other ceased to play. Luckily the tweeters on my speakers are fused, but when I did the math to see how much energy it would take to fry then it came out to 275 watts!? That's well past the rating for my amp, and for sure what caused them to fry was the clipping waveform.

Geoffcin
11-24-2009, 11:47 AM
Perhaps that is the answer to the original question posed by the car stereo guy.

rw

Car stereo?! You mean guys who do stuff like this;

http://www.youtube.com/watch?v=pthHmI5e7eU

audio amateur
11-24-2009, 02:20 PM
I really wonder the need for all that foul language

Geoffcin
11-24-2009, 03:18 PM
I really wonder the need for all that foul language

Brain damage caused by high amplitude bass exposure.....

hermanv
11-24-2009, 04:25 PM
Brain damage caused by high amplitude bass exposure.....
It's worse than you think. A British lad tested at a 10db loss of hearing sensitivity due to his excessively loud stereo. His response? "Oh good, now I can get more watts." Purportedly a true story.

Geoffcin
11-24-2009, 04:35 PM
It's worse than you think. A British lad tested at a 10db loss of hearing sensitivity due to his excessively loud stereo. His response? "Oh good, now I can get more watts." Purportedly a true story.

Oh I believe it. There's no way any of these guys who listen to music (and I use that word loosely) at these obscene levels are going to escape without massive hearing loss.

harley .guy07
11-24-2009, 06:48 PM
Oh I believe it. There's no way any of these guys who listen to music (and I use that word loosely) at these obscene levels are going to escape without massive hearing loss.

To clear myself of this I will say that I am not a music cranker as I listen at sane listening levels and was never a car audio bass head as some people on here might be I do know about car audio but I was always involved with the quality of the sound not the quantity of the bass.

Geoffcin
11-24-2009, 07:02 PM
To clear myself of this I will say that I am not a music cranker as I listen at sane listening levels and was never a car audio bass head as some people on here might be I do know about car audio but I was always involved with the quality of the sound not the quantity of the bass.

A likely story... To bad I've found a video of your family minivan in action;

http://www.youtube.com/watch?v=CewacsP6TSY&feature=PlayList&p=E5AD123AD65C3536&playnext=1&playnext_from=PL&index=66

Mr Peabody
11-24-2009, 07:27 PM
We are on our 4th page and nothing has really been settled or learned. It's not hard at all to find a woofer and tweeter with matching sensitivity. I posted several links that shows even with a single woofer in a box it takes more power to reproduce lower frequencies.

So, if a 2-way box speaker had matching tweeter and woofer in sensitivity, Geoffcin you maintain the crossover does nothing but separate the frequency? No effect on power at all? Hermanv, if this is his assertion is it correct? Why not?

The reason we have not reached a conclusion is most want to put out an opinion with nothing at all to back it up. I would have thought as mods and ties to the audio world that some one could have provided some hard evidence, facts. I don't want to argue, debate maybe, I want to know if I'm wrong, I want to know the facts. Geoffcin no matter your background I hope you don't just expect me to take your word over all that I have found.

poppachubby
11-24-2009, 07:38 PM
Peabody I appreciate what you're saying, but let's not confuse a biased Google search with real, hard research. Personally, I don't think anyone has done much to "prove" anything here.

Geoffcin
11-24-2009, 07:40 PM
We are on our 4th page and nothing has really been settled or learned. Geoffcin no matter your background I hope you don't just expect me to take your word over all that I have found.

Actually we're on the 6'th page now. But if you don't want to take my word on that I'm cool with it.

BallinWithNash
11-24-2009, 07:52 PM
enough of if the speaker was this or this. Let's talk about a normal enviroment ok, If you took my polks and my sub and played a high frequency through my polks and a low frequency on my sub at the same volume it would take more power to drive my sub especially if it is at 10Hz I almost clipped my amp (my crown) on the sub but my marantz was fine.

BallinWithNash
11-24-2009, 08:08 PM
I will say again, it takes less power to drive a larger speaker. It's just that simple.

Ok that makes no sense, then why don't we have are big amps (i am using big as in the amps that dish out the most power) powering are tweeters? if it takes less power to drive a bigger speaker. And if that is the case then it must require a lot less power to reproduce a high frequency because tweeter's basically require no power at all at least compared to subs, my sub is being driven by 450 watts my midange and tweeters are being driven by no more then 50 watts ... it's actually 40 watts that's all that is driving my tweet's and midrange but I have 450 watts going into my 12" sub??? so recap, it either takes more power to drive a bigger speaker or (key word OR) a lower frequency note takes more power to reproduce. Or both.

Mr Peabody
11-24-2009, 08:34 PM
Well, Poppa, Google or not, the posts are from reputable sources, not forums or heresay. Either way it's a damn sight better than you've done so far. You can't even think of an example of any one using a larger or even same size amp for tweeters in a multi amp set up. What you are saying is actually just stupid. At least the others have had a viable opposition. So you go ahead and put 25 watts on your woofer and 100 to 200 on the tweets and see what happens.

poppachubby
11-24-2009, 08:48 PM
Well, Poppa, Google or not, the posts are from reputable sources, not forums or heresay. Either way it's a damn sight better than you've done so far. You can't even think of an example of any one using a larger or even same size amp for tweeters in a multi amp set up. What you are saying is actually just stupid. At least the others have had a viable opposition. So you go ahead and put 25 watts on your woofer and 100 to 200 on the tweets and see what happens.

Why are you getting so mad? All of my posts have had disclaimers. It's what has been explained to me recently and I shared it. It seems to me that you can't get your head past this Big Speaker = Lower Power. Does it not seem conceivable to you that science works beyond the assumable?

Relax yourself. All I am saying is nobody here has gone out and done any research. It's just biased links from the internet. Do you know what research looks like? I do and I will be the first to say, no, I haven't done any.

Honestly, is Ballin With Nash really coming across with anymore clarity than me? Or is it just that he agrees with you?

BallinWithNash
11-24-2009, 08:53 PM
Honestly, is Ballin With Nash really coming across with anymore clarity than me? Or is it just that he agrees with you?
Hey, don't be dissing on me now I have tried not to poke fun at or make fun of other people this whole time. If you guys are going to do that that's fine just leave me out of it

BallinWithNash
11-24-2009, 08:54 PM
I did research I ran a high frequency and a low one like I explained earlier. The high one was handled fine the low one almost clipped ... My volume knob was the same for each i never turned it or eq'd it any differently.

poppachubby
11-24-2009, 08:57 PM
Ok that makes no sense, then why don't we have are big amps (i am using big as in the amps that dish out the most power) powering are tweeters? if it takes less power to drive a bigger speaker. And if that is the case then it must require a lot less power to reproduce a high frequency because tweeter's basically require no power at all at least compared to subs, my sub is being driven by 450 watts my midange and tweeters are being driven by no more then 50 watts ... it's actually 40 watts that's all that is driving my tweet's and midrange but I have 450 watts going into my 12" sub??? so recap, it either takes more power to drive a bigger speaker or (key word OR) a lower frequency note takes more power to reproduce. Or both.

Mr. Nash, unlike you I will not throw a bunch of numbers and jargon out there to try to prove a point. Clearly, this process involves a magnetic field and I suppose when the signal is introduced to a small field, the amp must work harder to further it. I don't know why, but you don't either and are really clutching at straws.

poppachubby
11-24-2009, 08:58 PM
Hey, don't be dissing on me now I have tried not to poke fun at or make fun of other people this whole time. If you guys are going to do that that's fine just leave me out of it


No diss, just stating the facts. You seem no clearer than me on this issue, regardless of your scientific endeavours.

BallinWithNash
11-24-2009, 09:03 PM
Clearly, this process involves a magnetic field and I suppose when the signal is introduced to a small field, the amp must work harder to further it. I don't know why, but you don't either and are really clutching at straws.

Yes but again no one has been able to prove me wrong. "it either takes more power to drive a bigger speaker or (key word OR) a lower frequency note takes more power to reproduce. Or both." Why do we put are big amps on are big speakers? a bigger speaker needs more air to be pushed which means it needs more power.

BallinWithNash
11-24-2009, 09:04 PM
O worded that very badly. i meant a bigger speaker pushes more air so it takes more power to be driven.

audio amateur
11-25-2009, 03:57 AM
We are on our 4th page and nothing has really been settled or learned. It's not hard at all to find a woofer and tweeter with matching sensitivity. I posted several links that shows even with a single woofer in a box it takes more power to reproduce lower frequencies.

So, if a 2-way box speaker had matching tweeter and woofer in sensitivity, Geoffcin you maintain the crossover does nothing but separate the frequency? No effect on power at all? Hermanv, if this is his assertion is it correct? Why not?

The reason we have not reached a conclusion is most want to put out an opinion with nothing at all to back it up. I would have thought as mods and ties to the audio world that some one could have provided some hard evidence, facts. I don't want to argue, debate maybe, I want to know if I'm wrong, I want to know the facts. Geoffcin no matter your background I hope you don't just expect me to take your word over all that I have found.
P, what you have done is come up with 3 links, one explaining that as a sub woofer's response in an enclosure rolls off you need more power to get the lower octaves up (not relevant), and the other two explaining conventional high-pass low-pass filters, which again, does not show that more power is required as you go down the frequency spectrum.

Geoffcin
11-25-2009, 06:00 AM
Yes but again no one has been able to prove me wrong. "it either takes more power to drive a bigger speaker or (key word OR) a lower frequency note takes more power to reproduce. Or both." Why do we put are big amps on are big speakers? a bigger speaker needs more air to be pushed which means it needs more power.


When you talk about bass reproduction, Poppa is essentially correct about bigger speakers needing less power to produce the same SPL. Smaller subs get around this by having much larger amps to compensate for their inefficient design, but there is a limit.

I don't know if you read my anecdote about the massive bass cab with the 109dB for one watt sensitivity, but just 1 watt into that puppy would shake your house to the foundation.

Also, we don't always put big amps on big speakers. Some of the largest designs are made specifically for modest power amps. Speakers like this;

http://www.avantgarde-acoustic.de/hornlautsprecher_daten.php?produkt=trio&t=daten&produkt_id=4

or this;

http://wilsonaudio.com/product_html/alex_specs.html

Hook either one of these massive speakers to your little 15 watt tube amp and watch the walls shake!

poppachubby
11-25-2009, 06:51 AM
Why do we put are big amps on are big speakers? a bigger speaker needs more air to be pushed which means it needs more power.

This is so subjective I don't even know where to start. Hey I know, why don't you address it Mr. Peabody?

Nash, perhaps you're familiar with Klipsch? Their whole "shtick" is super efficient speakers that are suitable for single ended tube amps or low RMS solid state amps.

How do they attain this? Not by building enclosures that require small speakers. Quite the opposite, woofers are 8 or 10 inches and they use horns to help with the tweeters inneffiency. They have been doing this for years, it's their trademark and has resulted in a distinctive "Klipsch sound".

Infact have a look at most ultra efficient speakers and what you'll find is sizable woofers in most. Cerwin Vega and JBL come to mind.

Please, I am as interested in knowing the truth on this subject as anyone else. Explain to me how it is that companies like Cerwin Vega can put a huge 15 inch speaker in an enclosure, and manage to have it only require 4ohms.

How is this efficiency achieved if the larger the speaker, the more power required?

Geoffcin
11-25-2009, 07:03 AM
O worded that very badly. i meant a bigger speaker pushes more air so it takes more power to be driven.

Yes, your correct a bigger speaker pushes more air per distance the driver travels, but it travels less distance to produce the same SPL so it really doesn't take more power to drive it. I think the mistake your making is because you FEEL a bass not you think it has more power, when it fact a 90dB bass not has EXACTLY the same energy as a 90dB treble note. A bass note will couple to your body leaving it's energy there, where a treble note will have a tendency to bounce right off of you. Even if your wearing treble absorbent clothing your not going to "feel" a treble note. your just not sensitive to it.

poppachubby
11-25-2009, 07:10 AM
Even if your wearing treble absorbent clothing your not going to "feel" a treble note. your just not sensitive to it.


Who would have thought that slicing hairs over speakers would produce our million dollar idea?!?

Introducing GeoffChubb Clothing Co.

Clothes for the serious audiophile. We provide fashionable clothing that will help you to feel those lost frequencies. Trust us, you'll be the only one in the room dancing with GeoffChubb wear. Available in many styles and colours, we have what you need.

Check out our new winter line:

35kHZ Parka with zipped Hood - $300
Treble Boost Polo, all colours - $40

Please visit us at www.yourastupidaudiophile.com for more info...

Geoffcin
11-25-2009, 07:21 AM
Who would have thought that slicing hairs over speakers would produce our million dollar idea?!?

Introducing GeoffChubb Clothing Co.

Clothes for the serious audiophile. We provide fashionable clothing that will help you to feel those lost frequencies. Trust us, you'll be the only one in the room dancing with GeoffChubb wear. Available in many styles and colours, we have what you need.

Check out our new winter line:

35kHZ Parka with zipped Hood - $300
Treble Boost Polo, all colours - $40

Please visit us at www.yourastupidaudiophile.com for more info...

Too funny! :lol:

poppachubby
11-25-2009, 07:29 AM
I thought so...

poppachubby
11-25-2009, 10:33 AM
Oh totally unrelated, but to add a little love to this wasteland of anger and confusion....

I caught the MMF and the Q2 today. Ever the voyeur, I got out the camera. PM me for more "in depth" pics.

Mr Peabody
11-25-2009, 08:36 PM
Poppa, you are at it again, no one ever said the bigger the speaker the more power, what was said is, it takes more power to reproduce a bass note, or low frequencies than higher ones. What's Klipsch or Wilson have to do with anything? It's a high sensitive box speaker that has both low and high frequency drivers which means nothing to what is being discussed. No wonder no one has anything to add, no one can remember the point of discussion. And, how can the articles be biased? Biased toward what? You think I called and had them custom written? Like I said you haven't found anything to dispute them, biased or otherwise. You guys go off on all these tangents and think you're disproving something.

AA, you either have reading comp issues or didn't bother reading the articles completely. They clearly talk about the power reduction as frequency goes up and increase as frequency goes down. You all are using the equalizer as an excuse to disregard, the speaker would need the same power to reproduce that low frequency whether or not the EQ was in place, that is, if the driver was capable of playing that low on it's own. You're just trying to repeat what Geoffcin posted which doesn't make it any more valid if you repeat it.

If you look at a power formula that uses "time" as one of the factors you will notice the longer the time the more power. So if you have a 16 kHz signal a wave isn't going to be long at 16,000 time a second. Where as one only 30 times a second, 30 Hz, will stretch quite a bit longer and need more power.

BallinWithNash
11-26-2009, 12:16 AM
Yea, no one has answered the original question and everybody keeps avoiding it ... and here I thought I could get a simple answer now we are going on 7 pages and haven't got much of anything to show ... I really don't personally care what the answer is I just what the correct answer because if I knew it I wouldn't have posted this topic. So back to the question does it take more power to produce a lower frequency versus a high frequency?

BallinWithNash
11-26-2009, 12:19 AM
And where in the hell is pixy??? he should have been in this argument by now.

audio amateur
11-26-2009, 04:19 AM
AA, you either have reading comp issues or didn't bother reading the articles completely. They clearly talk about the power reduction as frequency goes up and increase as frequency goes down.
Then perhaps it would help if you quoted the part you are refering to.

Mr Peabody
11-26-2009, 05:52 AM
Check my earlier posts, I did recap the part I wanted to emphasize and even used some caps. This was only in one post where I left a link.

Mr Peabody
11-26-2009, 07:30 AM
Here's a link from Axiom's website on bi-wiring & amping. This isn't perfect but notice where they mention the woofer will draw more current than the tweeter, more current equates to more power. Also, toward the end when talking about bi-amping they mention large amps for woofers and smaller amps for tweeters, no mention is a sensitivity factor.

http://www.axiomaudio.com/tips_biwiring_and_biamping.html

This still leaves us asking why but I found the answer stay tuned.

Mr Peabody
11-26-2009, 08:57 AM
Seems we all may have had some bits of truth and inaccuracies. This question is also far more complex than it sounds. I've read this and need to read it again and maybe again to fully grasp it all. There's a table that shows at around 350 Hz power is even and then falls off in either direction. However, he does state that in lower frequencies peak power demands will be greater. What's cool is the example uses Geoffcin's analogy of all drivers being even sensitivity. Although this answers a lot it also arises new questions for me. I've got some feelers out will post additional info if received.

http://sound.westhost.com/bi-amp.htm

Although I found the entire two part article very interesting here's the link to part 2 where he goes onto more information about applying amplifier power. http://sound.westhost.com/bi-amp2.htm

Mr Peabody
11-26-2009, 09:59 PM
This writer clearly states it takes more power for lower frequencies over mids or highs. He's not as big a fan of Bi-amping as the prior article. http://www.gcaudio.com/resources/howtos/biamping.html

So the prior link was not the definitive answer.

poppachubby
11-27-2009, 04:11 AM
This writer clearly states it takes more power for lower frequencies over mids or highs. He's not as big a fan of Bi-amping as the prior article. http://www.gcaudio.com/resources/howtos/biamping.html

So the prior link was not the definitive answer.

This was a nice link. It didn't feel like I was arriving in the middle of a topic or discussion. He lays out everything simply and concisely.

Clearly, what I have been saying is at great odds with what this guy is saying. I have been busy this week but I will certainly be talking to Mike, my tech mate, soon. I can't imagine why he would explain everything azz backwards, there must have been some point I missed or misunderstood.

I'll report back what I find out...

Geoffcin
11-27-2009, 07:52 AM
There's a table that shows at around 350 Hz power is even and then falls off in either direction. However, he does state that in lower frequencies peak power demands will be greater. What's cool is the example uses Geoffcin's analogy of all drivers being even sensitivity. Although this answers a lot it also arises new questions for me. I've got some feelers out will post additional info if received.

http://sound.westhost.com/bi-amp.htm

Although I found the entire two part article very interesting here's the link to part 2 where he goes onto more information about applying amplifier power. http://sound.westhost.com/bi-amp2.htm


Again, you've taken an article that you don't understand, and inferred things from it and are not what is stated. First off, he's stating that in the average program material, the center weighting of the signal is 350Hz. Half the tones will be higher, have the tones lower. That's IT!

The weighting scale givin in the article is in exact AGREEMENT with my statements. Taken that the program material center weighting is from 350Hz, as you move away from that hinge point you must provide more power to the respective drivers. Few speakers have their tweeter kick in at 350Hz, hence more of the TOTAL power would go to the woofer. This DOESN'T mean it takes more power to creat a bass note, only that the woofer's power requirements would be more based on it's GREATER coverage of the total bandwith of the program material.

I'm actually quite glad you've quoted this artical as the writer seems to have an in-debth understanding of sound reproduction, even if it's too much for some lay people to grasp.

As a matter of fact, if you would have grasped the meaning it would have bothered you, (but you miss-read it) so the author wrote a disclaimer;

"Since the last statement will possibly cause some discomfort or indeed confusion (after all, everyone knows that a subwoofer needs more power than the main speakers), I should explain myself. Most of the time in this article, I refer to power as average power, and indeed the average power falls with frequency below about 100Hz or so. The peak power is a different matter, and depends to a very great degree on the type of music"

And then goes on to telling you WHY a sub needs more power;

"
The table assumes equal efficiencies for the bass and mid+high drivers. Should they be different, then a correction factor must be added in. For example, if the bass driver were to be 3dB less efficient than the mid+high drivers, then the bass power must be doubled (and of course vice versa). If the difference is less than 3dB, you may safely double the power anyway, or calculate the actual power needed - this I shall leave as an exercise for the reader.
"
In addition he writes;

"In general, I suggest that the bass amplifier should have at least the same power as that used for the mid+high frequencies, but if any equalisation is used (such as the Project 71 Linkwitz Transform circuit), this may need to be increased dramatically. A boost of only 6dB may require that amp power be increased by 4 times."

Every bit of which I am in full agreement with.

Mr Peabody
11-27-2009, 10:32 AM
Well Geoffcin, you should have gone ahead and also cherry picked from part two where even a lay person can understand he explains the tweeter will use way less power. Unfortunately, he only compares the tweeter to the mid which doesn't address the low end that is in question. Too bad your intelligence is so far above us lay people and you still don't have the answer and still misinformed in regard to the original question.

audio amateur
11-27-2009, 10:47 AM
I can't really be bothered to read all that for the moment so I'll just go with whatever Geoff says, as I seem to have been in agreement with him since the start

Geoffcin
11-27-2009, 12:04 PM
This writer clearly states it takes more power for lower frequencies over mids or highs. He's not as big a fan of Bi-amping as the prior article. http://www.gcaudio.com/resources/howtos/biamping.html

So the prior link was not the definitive answer.

OK, this writer is clearly not an engineer, but he does grasp the effect of driver sensitivity on audio reproduction.

"Passive crossover networks found in consumer speakers waste an enormous amount of power. The often complex network is made up of large coils, chokes, capacitors and resistors. The circuit splits the full range signal into different frequencies (low, mid and high) appropriate for the different drivers in the speaker. Further, a crossover network compensates for efficiency differences in the drivers; woofers demand mode power than midrange drivers which in turn demand more power than tweeters, etc. Further, each of the drivers has different sensitivities, with some requiring far more (of far less) power than other drivers in the same speaker system. In a passive crossover, the excess power not required is dumped into resistors and burned off as heat. This makes for an incredible waste of power."

From the other article we've learned that a woofer that is crossed over at 350Hz would be required to cover HALF the (average) total musical signal, so it would need at least HALF the power of the entire speaker design.

Furthermore, most modest designs with two drivers have the woofer crossed over from 2kHz-3kHz. This would put even MORE of the total energy into the woofer. Also with a woofer that has a LOWER sensitivity (most, but not all woofers are less efficient than tweeters) than a tweeter crossed over at the higher frequency you could have designs where fully 90%(or more!) of the power is going to the woofer. NONE of this means it takes more power to make a lower frequency than a high note, nor is that what this writer is saying by stating that more power is going to the woofer.

I hate to say it but this is clearly another case of you NOT understanding the writer, and inferring something that was simply not stated by him.

Mr Peabody
11-27-2009, 02:05 PM
I hate to say it too but you are mixing the two articles together in a futile attempt to show something that isn't there.

Besides that if 350 Hz is mid point, and half your power was used to reproduce 350 down, that would certainly show it takes more power to reproduce low frequencies as there are more octaves below 350 than above to 20kHz.

BallinWithNash
11-27-2009, 09:49 PM
a true sub is crossed below 100Hz mine is crossed at 90Hz and I have a bigger amp driving it ... so the mid's and high's together cover much more total frequencies, they cover everything 91Hz and up! and im pretty sure you can't play a negative Hz so the sub is only playing 1-90Hz so what your saying Geoff is that high's and low's require the same amount of power but how? the sub cover's less and is driven by more power? that must lead you to one conclusion ... it takes more energy (power) to produce a lower frequency!

Geoffcin
11-28-2009, 05:51 AM
Hey, guys what takes more power to reproduce .... a high note or a low note?
So in other words the lower the note the more power or the higher the note the more power?

This was the question correct?

The answer is NO it doesn't take more power to produce a lower note. The reason your sub takes more power is that it's efficiency is less than your main speakers. If it were the same it would take EXACTLY the same power for every note, high or low.

Geoffcin
11-28-2009, 06:05 AM
I hate to say it too but you are mixing the two articles together in a futile attempt to show something that isn't there.

Besides that if 350 Hz is mid point, and half your power was used to reproduce 350 down, that would certainly show it takes more power to reproduce low frequencies as there are more octaves below 350 than above to 20kHz.

No, I am mixing the two articles to show you how you've been mistaken. Obviously you can't stand the fact that your logic is in error, so you will refuse to believe the truth no matter how plainly it's set out for you. I'm not going to further waste my time trying.

Mr Peabody
11-28-2009, 09:09 AM
Earlier I posted a link that explained lower frequencies take more power to reproduce due to the lower the frequency the further the woofer excursion so more power is meeded to push the woofer to those further reaches. I posed our question to a manufacturer's engineer and here's his response. I only asked about "low frequencies", after reading his response and Geoffcin's I reworded the question to specifically ask about woofers vs tweeters. I'll post that when and if received.

" For a given sound pressure level in a sealed subwoofer (the easiest example), cone excursion quadruples with each successively deeper octave. So going from 80 Hz to 40 Hz requires 4X more excursion, and going from 40 Hz to 20 Hz requires 4X more excursion again – so excursion at 20 Hz is 16X that of 80 Hz. More cone excursion generally requires more voltage of course.

There are compounding variables like the impedance load the subwoofer presents to the amplifier and the natural resonance frequency of the subwoofer system, which will exhibit a peak in the frequency response. Basically you look at the native (un-equalized) frequency response of the sealed subwoofer as an indicator of its relative sensitivity to a given drive voltage. Below the natural resonance peak of the subwoofer system (where it’s the most sensitive/efficient), the frequency response of the sealed subwoofer starts to roll-off at 12 dB/octave, which means that its becoming progressively less sensitive to a given drive voltage at progressively deeper frequencies. So if you wanted the subwoofer to maintain the same sound pressure at all frequencies below its natural resonance peak, you would need to feed it progressively more voltage (at a rate of 12 dB/octave) in order to accomplish that.

So it would be more accurate to state that if you wanted a subwoofer to reproduce frequencies below its natural resonance peak at sound pressures higher than it naturally wants to deliver with a given drive voltage, then yes – it certainly does require more power, and this would be reflected in the voltage transfer function (VTF) of the amplifier, which is essentially an inverse of the subwoofer frequency response and shows any cuts to reduce peaks at resonance, and also shows any boost (which by definition requires more power) to flatten/extend the frequency response deeper than the subwoofer wants to go naturally.

The below chart (courtesy of Linkwitz Labs) shows the natural FR of a sealed subwoofer, with a resonance peak of 55 Hz (system Q 1.21), and with a low-end response being -19 dB at 19 Hz. The equalized FR of the subwoofer shows a flat response with no resonance peak (i.e. system Q of around 0.5), and is now only -6 dB at 19 Hz, indicating considerably deeper extension than the native FR. The EQ curve (VTF) of the amplifier shows a cut at 55 Hz (where less power is required), and then a steadily rising power requirements showing 13 dB of boost at 19 Hz, in order to achieving the deeper extension. The boost curve levels off at about 10 Hz, but remains quite elevated with respect to the 0 dB reference level, indicating the higher drive voltage required to reproduce the deepest frequencies at SPLs louder than the subwoofer wants to play naturally."

I wish he hadn't gone on to talk about equalizing, at least Geoffcin agrees on that, but it doesn't void the statement in the first part of the response which reinforced the other link that the lower the frequency the further the excursion which requires more power. If no EQ it would still take more power to do 55Hz than 110Hz.

Geoffcin
11-28-2009, 12:55 PM
So it would be more accurate to state that if you wanted a subwoofer to reproduce frequencies below its natural resonance peak at sound pressures higher than it naturally wants to deliver with a given drive voltage, then yes it certainly does require more power, and this would be reflected in the voltage transfer function (VTF) of the amplifier, which is essentially an inverse of the subwoofer frequency response and shows any cuts to reduce peaks at resonance, and also shows any boost (which by definition requires more power) to flatten/extend the frequency response deeper than the subwoofer wants to go naturally.


Where does this say it take more power? When you go below the system's natural resonance. Duh!

Geoffcin
11-28-2009, 01:01 PM
.

" For a given sound pressure level in a sealed subwoofer (the easiest example), cone excursion quadruples with each successively deeper octave. So going from 80 Hz to 40 Hz requires 4X more excursion, and going from 40 Hz to 20 Hz requires 4X more excursion again so excursion at 20 Hz is 16X that of 80 Hz. More cone excursion generally requires more voltage of course. "

Yes, but remember, a woofer playing at 80Hz is required to cycle twice as fast as 40Hz wich requires 4X more power for the same travel. However it's also moving 1/4 the distance to make the same SPL so the equation balances.

Mr Peabody
11-28-2009, 01:26 PM
Oh, I see, so in your world the power goes down when voltage goes up? Interesting statement from a higher being. How many times are you quitting and returning any way?

Geoffcin
11-28-2009, 01:40 PM
Oh, I see, so in your world the power goes down when voltage goes up? Interesting statement from a higher being. How many times are you quitting and returning any way?

No, in my world we point out when someone takes something out of context and mis-understands what it means.

I can keep this up all day with you, but it's certain that you'll never get it. Mostly because you've set your mind to a point of view and refuse to budge from it no matter what proof is put before you. Actually you've managed to gather a great deal of good research, it's quite ironic that you refuse to take the time to understand it.

Mr Peabody
11-28-2009, 08:34 PM
I am trying to understand it but you are the one taking things out of context and can't even get power formula correct. And, you have not provided any proof of anything. You can claim all you want that I don't understand but I do understand enough to know the links posted certainly show you have not been correct.

BallinWithNash
11-29-2009, 12:55 AM
Peabody i love how he skips over my last post because there is no way he can prove it wrong haha!

Mr Peabody
11-29-2009, 11:21 AM
Remember though earlier I said this question wasn't cut & dry. I'm trying to get to the root of things. It seemes some things are true that contradict each other. I will be posting some more info later but only if I can connect all the dots. Posting parts of the puzzle isn't getting us any where. I have found a helpful source, I only hope I can get everything answered before he gets tired of me. :)

BallinWithNash
12-20-2009, 10:46 PM
Well ... have we come to a conclusion? any one still interested in this post?? hello??

Feanor
12-21-2009, 06:29 AM
Well ... have we come to a conclusion? any one still interested in this post?? hello??
No really, but I this might be the fact of the matter.

It takes the same measured power for a bass note as a treble, however human hearing is not as sensitive to bass as treble, accordingly bass notes must be produced with more power to be perceived as loud as treble notes. Consequently, since bass requires more power to be heard, bass amplifiers need to be more powerful.

Geoffcin
12-21-2009, 07:06 AM
No really, but I this might be the fact of the matter.

It takes the same measured power for a bass note as a treble, however human hearing is not as sensitive to bass as treble, accordingly bass notes must be produced with more power to be perceived as loud as treble notes. Consequently, since bass requires more power to be heard, bass amplifiers need to be more powerful.

When people listen at anything under 80dB or so the hearing response rolls off in both the bass and treble. To get around this many receivers have a "Loudness" control that boosts both the bass and treble. In addition when listening at low levels dynamic range is supressed too. You would have a tendency to loose low level detail. Many receivers also have a "midnight" or low level dynamic control that compresses the dynamics for better low level detail.

Audio engineers have know this for years, and when they mix a recording they listen at an exact median volume, (I believe 85dB) so that they can hear with the best ability that they can.

Feanor
12-21-2009, 08:06 AM
When people listen at anything under 80dB or so the hearing response rolls off in both the bass and treble. To get around this many receivers have a "Loudness" control that boosts both the bass and treble. In addition when listening at low levels dynamic range is supressed too. You would have a tendency to loose low level detail. Many receivers also have a "midnight" or low level dynamic control that compresses the dynamics for better low level detail.

Audio engineers have know this for years, and when they mix a recording they listen at an exact median volume, (I believe 85dB) so that they can hear with the best ability that they can.
Further this subject, if you have a Rat Shack SPL meter, you'll recall that they have an 'A' and a 'C' setting. The former approximates the typical perceived human hearing and reports bass a lower lever than the true energy. The latter, 'C', is a true, flat reading and, of course, is what to use for setting equalization

harley .guy07
12-21-2009, 09:04 AM
Well ... have we come to a conclusion? any one still interested in this post?? hello??

I gave up on my point a long time ago. I feel like I am back in damn high school in debate class reading this post. I know what I am talking about but some people are so set on what they want to say that they just can't realize that there is a lot of factors that can be variable in all of this and with human hearing being inaccurate at best then it also changes the simple part of the equation. So with taking that in to consideration I am done trying to make my points. Mr. Peabody has been the one that has shown the most data to back up his claims in my opinion and the rest of everyone is just hopping and skipping over things and arguing the points you want to argue and I guess that's fine but I have studied audio for many years and I know what I know to be true and that's all I could give two ^&*('s about and I will keep on keepin on.

Mr Peabody
12-21-2009, 06:00 PM
I'm done. I've consulted three different person sources, two engineers and one in the technical area for a manufacturer. In addition to the web articles. I don't know if it's in the way the question is posed or maybe there are many aspects to the question but I have yet to get anything that completely answers the question. There's a part of the puzzle missing. I still have the link to this thread and will come back if I ever find what I'm looking for.

In practice, whether pro sound or car audio we've always used larger amps on bass. If we could have gotten away with smaller power I'm sure it would be done in a cost saving measure.

It would seem if power was irrelevant when using tweeters and woofers of same sensitivity that more manufacturers would do that in order to conserve amp power and save on parts used to even out the power distribution within a speaker.

Nash, for now you'll just have to weigh what we have and draw your own conclusion. If you are into car audio, you let me know when you see some one using larger or even same size amps on their mid/tweeter section as they do on the subs. Whenever you see Alpine, Rockford, PPI, or any reputable car amp manufacturer make a 5 channel amp, the sub channel is several times larger than the satelite channels and they don't even know what speakers you will use. If it's four channel, at least two can be bridge. No one bridges for tweeters. It's just not done. Bass needs more power. There's more to the story than just sensitivity. What the complete answer is I am not able to deliver at this time or maybe never. It depends on if I ever find any one who actually knows and capable of conveying it in a logical form.

BallinWithNash
12-21-2009, 06:37 PM
Alright Harley, Pea, Geoff, and Feanor I'm going to keep the same conclusion I had at the beginning. I have read Pea's links now I may have not understood some parts very well but it seems logical to me that bass requires more power because almost all systems have more power going to the low's versus the high's. Thank you everyone for trying to come to a conclusion even if we couldn't get one.