Woofer Size: small ones can beat out larger size?

[RGA]

Exactly. That's one reason Totem makes pretty specific statements about what room sizes the speakers are intended for so you can get reasonable output at 40Hz. You won't get deafening output compared to larger speakers and if you're a basshead or listen to lots of the synth stuff it'll fall off on you but aside from that, and in a room that isn't too big, you can get good/satisfying/acceptable output down to 40Hz from those bookshelf speakers.

In short, I agree with you. It depends on a few things.

Well My reservations on Totem go beyond this but it is my taste. I am not about cranking to deafening levels because I don't, after all, want to go deaf. I hate generalizing but I do so here because it has always been my experience. The problem with very small speakers like the Model One and most other standmounts (such as the much bigger B&W 705) of low efficiency is that to get them to sound open and unboxy I feel the need to turn the volume up and up to make things out clearly. The lack of headroom then becomes an issue because these speakers don't tend to sound very good at low volume and they can;t play at loud volumes so now I have a huge problem with them. HE speakers tend to sound far more open at low levels. With my main speakers I don;t feel the need to turn it up to hear the bass or turn it up to make out the midrange. With the Model One even in a small room with powerful amplifiers it has numerous problems that for the price just don;t make sense to me.

I always walk away saying "great bass for their size - truly remarkable really - BUT in absolute terms the bass is not deep, it is not good at dynamics, it doesn't sound open or visceral and they cost a lot of money. To me it's a style oriented loudspeaker maker with good sound compared to other style oriented loudspeaker makers like Bose or Bang and Ollufson. But the Higher end dealers in the west had trouble selling them and so Totem jumped ship and moved into the big box chain A&B Sound. IMO that is the kiss of death. The high end dealers will never take them back - and they won't really sell at the prices Totem wants long term because if A&B does not sell them they will drop Totem or demand lower prices and that will force Totem to cheap out.

The Mani-2 is much better but at the price it too IMO has troubles and I mean the $3500.00 price you can buy them for not the $5000.00 list price. (Cad)

[O'Shag]

I think this was almost universally true at one point in time. Today, larger woofer's are not "slower" unless they have a relatively weaker motor system (with respect to the mass of the woofer).

Consider 3 woofers, a 6", 10" and 15" unit, all used in cabinets with system Q's of 0.707.
Each woofer is asked to play a 40Hz tone at 90 dB (I use this example because I have tests with woofers of the same product line/motor designs).
The 6" woofer requires 6.7 mm of excursion (which could be problematic since many only have 4-6 mm available.
The 10" woofer requires 2.3 mm of excursion (max of 8 mm)
The 15" woofer requires exactly 1 mm of excursion (max of 10 mm).

It's easy to see the larger woofers operating at much lower stress need to move shorter distances, and remain well within the realm of their motor's optimal operating range. The lower and louder the music you play, the "faster and clearer" you can expect a larger woofer to perform. The 15" woofer barely has to do anything at all compared to the 6' woofer which is operating near 100% of it's abilities.

Interesting and well explained response. The point about the motor and excursion makes a lot of sense.

[kexodusc]

Interesting and well explained response. The point about the motor and excursion makes a lot of sense.

Of course, when it comes to woofers I'm not aware of many 15" woofers that can be crossed over at 2000-3000 Hz in a 2-way system, lol. Larger drivers typically give up some midrange performance for the bass improvements...how the driver is used plays into it a lot as well.

[emorphien]

Well My reservations on Totem go beyond this but it is my taste. I am not about cranking to deafening levels because I don't, after all, want to go deaf. I hate generalizing but I do so here because it has always been my experience. The problem with very small speakers like the Model One and most other standmounts (such as the much bigger B&W 705) of low efficiency is that to get them to sound open and unboxy I feel the need to turn the volume up and up to make things out clearly. The lack of headroom then becomes an issue because these speakers don't tend to sound very good at low volume and they can;t play at loud volumes so now I have a huge problem with them. HE speakers tend to sound far more open at low levels. With my main speakers I don;t feel the need to turn it up to hear the bass or turn it up to make out the midrange. With the Model One even in a small room with powerful amplifiers it has numerous problems that for the price just don;t make sense to me.

I always walk away saying "great bass for their size - truly remarkable really - BUT in absolute terms the bass is not deep, it is not good at dynamics, it doesn't sound open or visceral and they cost a lot of money. To me it's a style oriented loudspeaker maker with good sound compared to other style oriented loudspeaker makers like Bose or Bang and Ollufson. But the Higher end dealers in the west had trouble selling them and so Totem jumped ship and moved into the big box chain A&B Sound. IMO that is the kiss of death. The high end dealers will never take them back - and they won't really sell at the prices Totem wants long term because if A&B does not sell them they will drop Totem or demand lower prices and that will force Totem to cheap out.

It is and can be a problem, but I don't find the need to play them or most other small standmount speakers at high volume to get them to really open up. I did notice this with some speakers, but with others (including the Eras and some other speakers) sound open and "unboxy" at low levels. As far as the problems selling them, I haven't seen anything like that with Totem or other small speaker brands here in the east. Don't know what you mean by A&B either, but after listening to a variety of things both in big box and high end dealers I came away with a handful of favorites of which the Totems were included.

I certainly did notice what you are talking about with other speaker brands, including some of the popular B&W and Paradigm models but what I liked so much about the Totems was they bucked that trend. The Focals were able to as well but with a different overall tonal balance and my second favorite would have been some of the PSB standmount speakers.

Certainly though, if I were to use them in a larger room then that wouldn't work. Most of these standmount speakers become boxed in and you lose the visceral impact in a larger room. But even at low levels in smaller listening rooms the visceral impact and bass depth out of many of the standmounts was satisfying (although for some it simply wasn't there too, or was either very sloppy or not really getting enough below 60Hz to fill in the bottom end suitably).

[GMichael]

Will big dogs always have bigger woofers than small dogs? And which ones will have less distortion? Can I have three small dogs woof as good and one big dog? Which ones will be faster? I would think that the smaller dogs would be quicker but the big dog would be faster in the long haul. What do you think?

[cocopeep]

Will big dogs always have bigger woofers than small dogs? And which ones will have less distortion? Can I have three small dogs woof as good and one big dog? Which ones will be faster? I would think that the smaller dogs would be quicker but the big dog would be faster in the long haul. What do you think?

Thats a good point even a caveman can understand!

[O'Shag]

I'm currently listening to Sirius Satellite Area 33 (rave/trance) - don't knock me about, I listen to every type of music - Bloomin 'eck but the Spectron 1KWs (1000watts!!) I just got are the darned fastest amps I've ever heard. The bass is unbelievable. They leave my Mark Levinson No. 27 monos and ARC Classic 150 monos in the dust, and they're both excellent. The Monitor Audio Gold Reference 60s have two six inch ceramic woofers per side in a ported disign. I'm wondering how 2 really fast 15" woofers per side will sound with the spectron driving them. Bloody heck, all the neighbours would think there's an earthquake.

[kexodusc]

I'm currently listening to Sirius Satellite Area 33 (rave/trance) - don't knock me about, I listen to every type of music - Bloomin 'eck but the Spectron 1KWs (1000watts!!) I just got are the darned fastest amps I've ever heard. The bass is unbelievable. They leave my Mark Levinson No. 27 monos and ARC Classic 150 monos in the dust, and they're both excellent. The Monitor Audio Gold Reference 60s have two six inch ceramic woofers per side in a ported disign. I'm wondering how 2 really fast 15" woofers per side will sound with the spectron driving them. Bloody heck, all the neighbours would think there's an earthquake.

Here ya go...except I'd opt for the 18" version....lemme know if ya get the urge, I'd love to design a sealed or ported subwoofer with these...

http://www.tcsounds.com/lms5400.htm

Check out the size of the grizzly magnet -

These ain't your neighbor's kid's trunk kicker's....75 lbs of glorious bass...

[O'Shag]

Wow! Kexodusc, those woofers look amazing. The magnet is enormous. They use a metal woofer material. Have you tried these? Also, are there disadvantage to using seperate subwoofers as opposed to a single enclosure?

[GMichael]

Here ya go...except I'd opt for the 18" version....lemme know if ya get the urge, I'd love to design a sealed or ported subwoofer with these...

http://www.tcsounds.com/lms5400.htm

Check out the size of the grizzly magnet -

These ain't your neighbor's kid's trunk kicker's....75 lbs of glorious bass...

I think I just wet myself. What amp would you use for these?

[kexodusc]

Wow! Kexodusc, those woofers look amazing. The magnet is enormous. They use a metal woofer material. Have you tried these?

I haven't used these particular subs - the highest I've ever personally heard is their TC-5200 model which is a step below and a few hundred less - it was used with some big expensive Maggies and added a real vibrant kick at the bottom end that totally elevated the overall performance that system could generate. The owner debated a long time before deciding on incorporating separate subwoofers. In hindsight, he admits he probably could have improved his system with woofers at 1/3 the cost, but he's extremely happy now.

Nothing wrong with metallic woofers - in smaller mid-woofers there's often a few break-up nodes. This gave metal drivers a bad rap-sheet decades ago when lower, simpler crossovers were used. In truth the problem is easy to solve with a good crossover - look at all those high-end speaker manufacturers who use Seas and Scan-speak drivers.

For sub purposes, there'll be at least a 12 dB/octave filter on the sub, plus the natural roll-off of the driver, so any break-up (if present at all) would be alleviated. You could put a filter in the design yourself if need as well, I suppose.

Also, are there disadvantage to using separate subwoofers as opposed to a single enclosure?

I'd argue using separate subs outside the speaker enclosure offers more benefits than having the bass source incorporated into the enclosure when trying to achieve optima performance.

Room acoustics play a bigger part in the sound below 100 Hz than arguably even the speakers themselves. It's a fact that the best place for the bass transducer is rarely the best place for stereo speaker performance in the mid-range and higher frequencies. Depending where you position the subs, and what frequency you select, any phase problems can be made a non-issue. If you place them beside symmetrically beside the towers, but perhaps closer to the walls/corners you're fine. The further off-axis you go,the lower you'll need to set your xo, however. I'm not aware of many subs that don't have a phase-adjustment option. And this phase alignment isn't anything dramatically different from the phase alignment your speaker's crossovers have built into them, anyway. Our ability to resolve incoherencies diminishes greatly below 100 Hz, so the tolerance range for optimum performance thankfully is considerably more forgiving.

The downside is that adding subs will definitely increase the complexity of set-up. It'll take a some reading, learning, and definitely some trial and error. Just adding a subwoofer or two in a corner and setting the crossover at arbitrarily low position like 40 Hz isn't going to guarantee success. I think a lot of people are just happy enough with what they have to not bother. Incorporating two more big boxes into a room isn't always a viable option in the household for a number of reasons. Budget, perceived value, etc. Nothing wrong with that. Those that do go this extra step though are happy they did.

[basite]

I think I just wet myself. What amp would you use for these?

yeah, me too


something with 1 KW at least...




... per voice coil...

that thing will bring a house down...

btw, best sub I ever heard till now was a REL studio III in an uber expensive HT setup (at a high end shop), however it 'only' had 2 10" drivers, it gave the most gigantic bass i've ever heard in a HT setup

[kexodusc]

I think I just wet myself. What amp would you use for these?

Whatever you want, I guess.
I've sort of fallen for these two models after some demonstrations that have me rethinking my beliefs about amplifiers. I'm not even going to go into that out of fear of being flamed.
This is probably what I'm going to buy for my IB setup.
http://www.partsexpress.com/pe/showd...number=248-745

I helped one guy in town build his IB setup. He uses the 2500 model (a bit more power) than the above, and also has 3 inexpensive Crown amps in his home theater :
http://www.partsexpress.com/pe/showd...number=245-465
I couldn't believe how good this thing sounded running his PMC speakers, of all things.

There's some excellent sounding QSC and Crown amps out there as well that probably have a bit more power if you want bragging rights:
http://www.partsexpress.com/pe/showd...number=245-642

I'm going to stop now before people gang up on me.

[kexodusc]

btw, best sub I ever heard till now was a REL studio III in an uber expensive HT setup (at a high end shop), however it 'only' had 2 10" drivers, it gave the most gigantic bass i've ever heard in a HT setup

I'm not completely shocked. There's benefits to multiple drivers in some applications vs 1 big expensive driver with long excursion - I doubt REL even bothers offering a 18" subwoofer. I'm guessing not too many wives would let that fly. Coming from a guy who's thinking 4 15" woofers for my next sub.

[GMichael]

Whatever you want, I guess.
I've sort of fallen for these two models after some demonstrations that have me rethinking my beliefs about amplifiers. I'm not even going to go into that out of fear of being flamed.
This is probably what I'm going to buy for my IB setup.
http://www.partsexpress.com/pe/showd...number=248-745

I helped one guy in town build his IB setup. He uses the 2500 model (a bit more power) than the above, and also has 3 inexpensive Crown amps in his home theater :
http://www.partsexpress.com/pe/showd...number=245-465
I couldn't believe how good this thing sounded running his PMC speakers, of all things.

There's some excellent sounding QSC and Crown amps out there as well that probably have a bit more power if you want bragging rights:
http://www.partsexpress.com/pe/showd...number=245-642

I'm going to stop now before people gang up on me.

I would think that any of these would do a good job. Number 3 looks best but number 1 seems to be the best "fit" for the buck.

[GMichael]

I'm not completely shocked. There's benefits to multiple drivers in some applications vs 1 big expensive driver with long excursion - I doubt REL even bothers offering a 18" subwoofer. I'm guessing not too many wives would let that fly. Coming from a guy who's thinking 4 15" woofers for my next sub.

How about 2 of those 18"ers and amp number 3?

[Luvin Da Blues]

Those that do go this extra step though are happy they did.

[kexodusc]

How about 2 of those 18"ers and amp number 3?

Take your pick, there's lots of big monoblocks out there and you really could spend as much as you want.
For me, I could get buy on a couple hundred watts a side, and would rather spend the money on the subwoofers themselves. Don't want to go too cheap, but we're not going to resolve the finer subtleties with 18" drivers either, so a top end Krell or whatever is probably overkill.

[Feanor]

Wow! Kexodusc, those woofers look amazing. The magnet is enormous. They use a metal woofer material. Have you tried these? Also, are there disadvantage to using seperate subwoofers as opposed to a single enclosure?

'Shag, I assuming you're asking about multiple subwoofers vs. a "full range" speaker?

One potential advantage of a pair of subwoofers, one for each channel, is a higher crossover point than possible with a single subwoofer. The limit for hi-fi sound from a single subwoofer is no higher than 80Hz which is where sound be becomes directional. If you have "stereo" subwoofers you can raise this as high as you like within the capabilities of the subwoofers themselve, e.g. 100, 120, even 200Hz.

To do this, you ought to have not only low-pass filters for your subwoofers but also high-pass for you main speakers: it is important to keep the low frequencies out of the latter in the interest of better balance, lower distortion, and greater power handling without destroying your main speakers.

[hermanv]

Hey guys, are you so young that you forgot about the sweet 16. It used 16, 5" drivers wired series parallel so as to maintain the either 4 or 8 Ohm driver impedance. The designer reasoned that 16 x 5" diameter drivers had the same surface area as one 20" driver. The math was good but the principle is not.

Drivers have a parameter usually called Fs or Fo this is the natural frequency of the cone (mass) and the spring of the support structure (surround and spider). A typical 5" driver may have an Fs of 60Hz. Drivers will not produce useful sound pressures at any frequency lower than Fs.

[cocopeep]

So you are saying that you can have as many 5 inch drivers together in a cabinet but cannot go below 60 Hz?

[hermanv]

Not exactly. I'm saying you can't go below Fs of the driver. I found one 5 1/4" driver that had an Fs of 31.5Hz. So one or more of them would reach 31.5 Hz. the advantage of more drivers is smaller cone excursion per dB SPL of output.

[kexodusc]

Not exactly. I'm saying you can't go below Fs of the driver. I found one 5 1/4" driver that had an Fs of 31.5Hz. So one or more of them would reach 31.5 Hz. the advantage of more drivers is smaller cone excursion per dB SPL of output.

To expand on what hermanv is saying:

Contrary to popular belief, woofers can and do play well below their Fs (even in free air), they just don't do as efficiently, or very well (distortion, max excursion, etc - ever hear that warbly farting noise some smalls subs make?) The amount of sound output of the speaker per given unit of energy falls at 12 dB per ocatve below the resonance. But it's not a hard cutoff where the speaker doesn't make any more sound output.

Fs refers to the free air resonant frequency of the driver. Ie, suspend a driver on a string from the ceiling, not in a box. How many speaker systems do you know operate in free air?

When you put the driver in a ported box, the acoustic roll off changes - 24 db for ported systems per octave. The resonant frequency of the "system" (or resonant frequency of the driver in a given box) also changes for both sealed and ported enclosures.
Depending on how you tune the box, you can easily go below the Fs of the driver in an ported design. If a 5" speaker had a Fs at 31.5, I'd expect a ported system to play even lower...especially in most typical home room sizes. Depending on room acoustics, you can achieve flat response below Fs in a sealed design too, a bit more difficult though.

[hermanv]

To expand on what hermanv is saying:

Contrary to popular belief, woofers can and do play well below their Fs (even in free air), they just don't do as efficiently, or very well (distortion, max excursion, etc - ever hear that warbly farting noise some smalls subs make?) The amount of sound output of the speaker per given unit of energy falls at 12 dB per ocatve below the resonance. But it's not a hard cutoff where the speaker doesn't make any more sound output.

Fs refers to the free air resonant frequency of the driver. Ie, suspend a driver on a string from the ceiling, not in a box. How many speaker systems do you know operate in free air?

Well I've been wrong before, probably even today. I believe Fs is traditonally measured in an infinite baffle or the Europeans seem to be fond of a 1 meter square baffle. This is not the same as free air resonance. As you point out drivers are never run this way so providing the Fs specification that way provides no help to the speaker designer in chosing a driver.

For me at least, the goal is flat frequency response, yes the cone still moves below Fs not only is efficiency shot to hell, so are the distortion numbers. The curve is so steep that equalizing for it is generally unwise . Take your example; if you wanted to equalize for a 24 dB error (12 dB from the driver plus another 12 dB for the box, the speaker is mounted in) for one ocatve you need 24 db more power. If the system is running at 1 watt you'll need 254 watts at that low equalization point. Or if you are running at 10 watts suddenly 2,540 watts are needed, the driver will not like this. Of course you will enjoy the advantage of being able to examine the cone from all sides since it will most likely land in your lap

Many modern speakers will use 2 six inch drivers or 2 eight inch drivers for their woofer. These are almost always custom driver units made especially for this job. High excursion, low Fs and hopefully low distortion. This idea became much more popular as home theater systems couldn''t afford the cost or the space for good low frequency performance.

[kexodusc]

Well I've been wrong before, probably even today.

LOL, according to my wife I can't do anything right...

I believe Fs is traditonally measured in an infinite baffle or the Europeans seem to be fond of a 1 meter square baffle..

That's correct, some of the companies in Denmark use some odd ball shaped baffles but after a meter or so it works for measurment purposes.

This is not the same as free air resonance. As you point out drivers are never run this way so providing the Fs specification that way provides no help to the speaker designer in chosing a driver.

No that's not accurate. The Fs taken this way is absolutely useful, and necessary. If you don't know the Fs as provided, you'll have a hell of a time designing an enclosure to achieve a flat response, good power handling, optimum bass extension, etc. You wouldn't know where to start. The trial and error would be tedious, expensive, and time consuming.

Again, for determining the free-air resonant frequency of the driver, an infinite baffle (or quasi-infinite baffle for the smaller weird shapes) doesn't put the driver in an enclosure, so there's no resistance against the driver's movement, and it's not going to have any impact on the compliance and damping of the driver that would change the resonant frequency. Effectively, for this Fs measurement it is free-air.

FWIW, I believe simple action-reaction is the reason they don't actually suspend a driver from a string. Instead of the woofer moving the air, the woofer would act like a motor and move itself some as well and a lot of energy would be wasted...though to be honest, I've never looked into that and I could be wrong. Also, when they test the woofer's T/S parameters on a wide baffle, they're usually also measuring frequency response. You need the wide baffle so the frequency responce doesn't include any baffle step loss.

For me at least, the goal is flat frequency response, yes the cone still moves below Fs not only is efficiency shot to hell, so are the distortion numbers. The curve is so steep that equalizing for it is generally unwise . Take your example; if you wanted to equalize for a 24 dB error (12 dB from the driver plus another 12 dB for the box, the speaker is mounted in) for one ocatve you need 24 db more power. If the system is running at 1 watt you'll need 254 watts at that low equalization point. Or if you are running at 10 watts suddenly 2,540 watts are needed, the driver will not like this. Of course you will enjoy the advantage of being able to examine the cone from all sides since it will most likely land in your lap .

I hope the goal for everyone is reasonably flat frequency response Of course there's at least one company who shall remain nameless BOSE that seems to care little.

You're absolutely right, distortion will increase as the power required to drive the speaker to a certain volume increases, but it's not fair to say the distortion numbers are shot to hell immediately below Fs - there's still a fair amount of sound below Fs at decent volume that can be squeezed out of the driver, depending on the application, and of course depending on the quality of the driver. A lot of speakers are designed to output frequencies below the Fs of the driver.

You raise a good point in your power/dB exercise - in ported sytems, there's an increase of power required to maintain volume. The further away from the resonant frequency you move, the more power you'll need. The first several Hz aren't so bad, and can often be EQ'd if someone really wants to (in a sub I could see, in a speaker I'd have to ask why), but much further than that as you pointed out, and the power requirements get pretty ridiculous. The 24 dB you used applies only to the frequency 1 octave away from the resonant frequency of the speaker system with a ported enclosure, Fb (which can and most often is significantly lower than Fs).

Also, in practice, a lot of sealed speakers and infinite baffle systems depend on matching the roll-off of the driver with the transfer function of the room it will be played in to extend the low frequency. If you look at some of the IB subs Tom Nousaine and others have had in Stereophile and other mags over the years, they often include decent excursion and power handling, and eq'ing to push the driver down to 10 Hz is used. A bit excessive to me but Tom likes his bass I guess I've heard but 2 IB sub systems, nothing fancy or expensive, and it just sounds so much better it's absolutely incredible - but that's another thread.

Many modern speakers will use 2 six inch drivers or 2 eight inch drivers for their woofer. These are almost always custom driver units made especially for this job. High excursion, low Fs and hopefully low distortion. This idea became much more popular as home theater systems couldn''t afford the cost or the space for good low frequency performance.

I'm not sure I understand what you're saying here? A lot of mulit-woofer designs use a 2nd woofer for a variety of reasons, ie, MTM alignments, where more bass is just an afterthought.

I'm guessing that sweet 16 speaker was a line array - to counter the 24 dB/octave roll-off if it was ported (or 12 dB roll-off if it was sealed), the guy probably designed the crossover so that 4 or 8 woofers were responsible for a common passband in the bass region - the added gain from compounding the drivers would offset the roll-off.
There's a lot of very impressive speakers designed as such with incredibly low distortion - but I tend to agree with you - why use a 16 5" woofers to when 2 5" woofers and a big ol' 12" can get the job done with far less complexity, size, and cost?