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stevef22
11-16-2007, 05:24 PM
I was just reading on a another thread about blowing speakers. How can one watt really be that loud when receivers and amplifiers are rated 50-100+ watts?

I know that music and movies often times "spike" and get super loud or a car might crash into a wall. Is this peek when the receiver uses all the wattage?

I just picked up the Yamaha RX-V995 5.1 Receiver and its rates at 100 watts per channel with .04 THD distortion 20-20hz. Is this good? Can this power Cerwin Vega VS 12" Floor speakers for the main channel?

kexodusc
11-16-2007, 06:34 PM
Watts aren't units of loudness.
Loudness depends as much on the ability of the speaker to turn the power from the amp into sound pressure (loudness).

Most speakers today are reasonably efficient at converting electrical power to sound level, at around 88 to 90 dB at 1 watt measured at 1 meter distance from the speaker.

This is pretty loud. Concerts are 100 -105 dB or so. On 90 dB efficient speakers at 10 feet distance, we'd need about 20 watts or so to reproduce that.

The 995 was a serious heavyweight receiver back in its day. It will have plenty of power for you. Whether it's enough depends on how loud you want things to get.

SlumpBuster
11-16-2007, 07:31 PM
Kex is right. I have a vintage Yamaha M-65 amp combined with speakers that have a sensitivity of 97db/watt. That means that with only 1 watt I should be getting 97dbs measured at 1 meter. That is very loud. The amp has a meter that goes up from .003 watts to 500 watts. I've never seen it spike above 30 watts and its usually loitering at .3 watts. You'll probably be getting similar performance with the CVs.

One watt can be very loud. Take a look at these Pass Labs First Watt amplifiers. A whole line based on the concept that you really only need that first watt.http://www.firstwatt.com/index.html

Mr Peabody
11-17-2007, 08:53 PM
What blows a speaker though is when you demand more than that one watt and the second isn't there. When an amp runs out of horsepower it's output signal wave becomes jagged instead of smooth which you will hear as distortion or loss of clarity, it's this that blows speakers quicker than anything.

From what I understand from another thread the CV's have a protective circuit so if you did get crazy the most you would do is blow the fuse.

This may help: http://www.phys.unsw.edu.au/jw/dB.html

pixelthis
11-19-2007, 01:09 AM
Its worse for a speaker to be underpowered than overpowered, as this will induce something called clipping. Very bad.
A lot of people have a misconception about "watts", seldom will your receiver be using more than 4 or 5.
Notice your receiver is rated 20 to 20,000 herzt? This means that your receiver will produce as advertized at all audilble frequencies.
Probably for about five minutes.
MOST USED TO ADVERTISE a power rating measured as 1 khz, great if you listen to stuff with one audible frequency. Their watt rating was rather unrealistic also.
Now they are rated across the full audible specturm with something call RMS, a
more realistic way of doing things. But they dont tell you how long it will run like that.
DON'T NEED TO. If you ran your receiver "full blast" that is what you'd probably get.
Something blowing up
My first receiver was a Yamaha stereo rated at 30 watts per channel(back when Yamaha
still made audiophile equipment) and that was plenty

Most "measurements " that audio companies put out are marketing gimmicks.
There is no standard for rating contrast in TV for example.
Why are you worried anyway? Blow a pair of cerwins and you probably couldnt tell much difference anyway:1:

pixelthis
11-19-2007, 01:19 AM
I had a yammy RXV 750 for awhile and they do make good HT receivers.
They make their own proprietary decoding chips, too.
Only problem I had was blowing a cap on the digital board.
Yamaha pays attention to something called "damping factor" one of the few receiver
companies that do. Damping factor is one of the differences between standalone amps and receivers. Most have damping factors of 30 to 60, most seperate power amps have damping factors of anywhere fron 200 to 500. This is why damping factor isnt mentioned in receiver specs much. My receiver is midpriced at 1200 bucks and its damping
factor is 45 or so.
Some think yammys precise sound is a bit "harsh" but I disagree, anyway when your taste in speakers improves and you want something that produces more than
industrial noise, check out speakers with soft dome tweeters, like B&W.
My yammy ran beemers quite well, but I am a hugh fan of their speakers

basite
11-19-2007, 07:53 AM
as a mac owner I see my meters move.

1 watt is loud enough, not killing loud, and your walls won't fall apart, but yeah, it's loud :D

you do know that from 1 watt to 2 watts is just a 3 db increase, and from 2 to 4 another 3db, and from 4 to 8 another 3, and so on. Watts are pretty much meaningless too, I prefer thinking in current :)

Keep them spinning,
Bert.

pixelthis
11-20-2007, 01:46 AM
as a mac owner I see my meters move.

1 watt is loud enough, not killing loud, and your walls won't fall apart, but yeah, it's loud :D

you do know that from 1 watt to 2 watts is just a 3 db increase, and from 2 to 4 another 3db, and from 4 to 8 another 3, and so on. Watts are pretty much meaningless too, I prefer thinking in current :)

Keep them spinning,
Bert.

It gets to the point that you have to DOUBLE your power output for a 10 db increase!
MAC owner eh. Where do you live and when are you at work?:ihih:

bfalls
11-20-2007, 08:12 AM
Kex is right. I have a vintage Yamaha M-65 amp combined with speakers that have a sensitivity of 97db/watt. That means that with only 1 watt I should be getting 97dbs measured at 1 meter. That is very loud. The amp has a meter that goes up from .003 watts to 500 watts. I've never seen it spike above 30 watts and its usually loitering at .3 watts. You'll probably be getting similar performance with the CVs.

One watt can be very loud. Take a look at these Pass Labs First Watt amplifiers. A whole line based on the concept that you really only need that first watt.http://www.firstwatt.com/index.html

Slumpbuster kudos on the Yamaha M-65. I've had mine for 10 years and still love it. I use it for bi-amping my Legacy Focus' 3 - 12"/side woofers. I have it paired with a Denon AVR-3300 for the remaining 5 channels. It's a great heavyweight amp, ClassA up to 20W and looks great. I've been looking for an M-85, but haven't wanted to pay the money most are asking. Some I've seen have had a pretty rough life. Do you find the wattage meters accurate for your speakers.

You state your speakers are 97db efficient. They must be horns of some type, Klipsch perhaps. I have another system using a Yamaha RX-V2095 with Klipsch Kg4 (94bd efficient), RS3s, KLF-C7/KV3 and custom ACI Saturn sub. It's usually not recommended to use Yamaha with horns, (supposedly harsh sounding) but I haven't noticed any issues. Although my Denon system costs many times more then the Yamaha, both are very respectable. One not necessarily better than the other, just different.

basite
11-20-2007, 08:39 AM
It gets to the point that you have to DOUBLE your power output for a 10 db increase!
MAC owner eh. Where do you live and when are you at work?:ihih:

eh no, you'll have to double your output for a 3 db increase, not for a 10db increase...

Mr Peabody
11-20-2007, 07:08 PM
Bassite, Pix, before this thread turns into another one of those arguments, please read the article from the link here in an earlier post of mine, called "What Is A Decibel". What you both are talking about is a ratio and people pick out only part of the facts. After reading the article you'll see it's difficult to put simply.

SlumpBuster
11-20-2007, 07:54 PM
Slumpbuster kudos on the Yamaha M-65. I've had mine for 10 years and still love it. I use it for bi-amping my Legacy Focus' 3 - 12"/side woofers. I have it paired with a Denon AVR-3300 for the remaining 5 channels. It's a great heavyweight amp, ClassA up to 20W and looks great. I've been looking for an M-85, but haven't wanted to pay the money most are asking. Some I've seen have had a pretty rough life. Do you find the wattage meters accurate for your speakers.

You state your speakers are 97db efficient. They must be horns of some type, Klipsch perhaps. I have another system using a Yamaha RX-V2095 with Klipsch Kg4 (94bd efficient), RS3s, KLF-C7/KV3 and custom ACI Saturn sub. It's usually not recommended to use Yamaha with horns, (supposedly harsh sounding) but I haven't noticed any issues. Although my Denon system costs many times more then the Yamaha, both are very respectable. One not necessarily better than the other, just different.


Hey thanks. I'm a big Yamaha fanboy. Yeah, I found the price jump with the M-85 to not be worth it. Nope, no horns though. Paradigm Monitor 11. The meter is plenty accurate, at least as far as my Rat Shack meter and Rives disk go. The speakers are rated 97db/w in room response or 94db/w anechoic, and that is a pretty accurate in room rating... at least in my room. I use a Yammie RXV1500 reciever with the amp. The receiver has a very accurate volume control too. Punch in a .5 db increase, you get a .5 db increase. Between cross referencing the reciever volume control, the meters on the amp, and the Rat Shack SPL meter, it is all very accurate and allows for pretty precise control.

When I say that the meters have never been above 30 watts, that is not entirely true. I once peaked at 90 watts. Combined with the a Titanic sub, I was getting 123db in room at the listening position all the way down to 20hz. The Titanic has a dedicated 30 amp circuit that had a lamp plugged into the same wall outlet. Every time the bass hit the lamp would dim. The Titanic amp was pushing way more than 90 watts. :D When I was younger I probably would have played the system that loud all the time. But now that I'm older its kinda like "Well, okay, so don't need to do that again."

pixelthis
11-21-2007, 02:13 AM
Bassite, Pix, before this thread turns into another one of those arguments, please read the article from the link here in an earlier post of mine, called "What Is A Decibel". What you both are talking about is a ratio and people pick out only part of the facts. After reading the article you'll see it's difficult to put simply.

No argument from me, I just know that you have to double the wattage at some point to
get a small increase in loudness, dont remember the exact figures, but we seem to agree on the basic point
I was just using the 10 db to illustrate my point, could be 3, doesnt matter that much if we agree on the basics, which is that you hit the law of diminshing returns sooner or later

pixelthis
11-21-2007, 02:23 AM
One more fact, more efficent speakers are usually cheaper and let you save big bucks
on amperage, you save money on amps and speakers.
Sometimes you just have to have a pair of "coffins" standing upright, but they will cost you in the price you have to pay out for electronics.
My first receiver from realistic (MADE BY PIONEER) put out about 20wpc, my first serious receiver was 35 or so. I once bought a top of the line denon that was 75 per channel (two channel) and a pioneer integrated that had a stellar 10 wpc.
All of these sounded great, you just couldnt run a six foot tall floorstander with em:1:

markw
11-21-2007, 06:11 AM
eh no, you'll have to double your output for a 3 db increase, not for a 10db increase...Three db is barely audiable. A 10 db increase translates to roughly twice the apparant loudness, and this requires about 10 times the power.

Luvin Da Blues
11-21-2007, 07:34 AM
Three db is barely audiable. A 10 db increase translates to roughly twice the apparant loudness, and this requires about 10 times the power.

I always thought that...One db is barely audiable. A 3 db increase translates to roughly twice the apparant loudness, and this requires about 10 times the power..hmmmm:confused5:

markw
11-21-2007, 08:18 AM
I always thought that...One db is barely audiable. A 3 db increase translates to roughly twice the apparant loudness, and this requires about 10 times the power..hmmmm:confused5:Watts (Power), Decibles and Loudness have a strange, non-linear relationship. A lot of people don't realize this and go through this hobby mis-stating the facts.

This article goes into some detail but basically check the last chart on the page, particularly the first, third, and fourth columns.

http://www.audioholics.com/education/frequently-asked-questions/relationship-between-watts-and-dbs

Luvin Da Blues
11-21-2007, 12:49 PM
Watts (Power), Decibles and Loudness have a strange, non-linear relationship. A lot of people don't realize this and go through this hobby mis-stating the facts.

This article goes into some detail but basically check the last chart on the page, particularly the first, third, and fourth columns.

http://www.audioholics.com/education/frequently-asked-questions/relationship-between-watts-and-dbs


And I thank you for that...very informative :cornut:

Robert-The-Rambler
11-22-2007, 08:51 AM
I read somewhere that when driving speakers with different sensitivities for every 3db increase in sensitivity it would take half the power to have the same volume ratio. Maybe I'm makng up a new term but by that I mean as you turn up the volume the gain would virtually be the same. For example, my DCM KX12 Series 2 speakers have a sensitivity of 99db. I think the sensitivity of my "lowly" Sony speakers are about 90db. With that logic with lets say a 100 watt amp the DCMs would be 8 times as loud. Okay that seems to be somewhat accurate when it comes amps with the same power and gain.

Now it is a different story altogether when you talk different amps with different voltage gains and an ability drive different amounts of current. In that case all bets are off. You might have very different results prior to clippage.
.

markw
11-22-2007, 08:50 PM
I read somewhere that when driving speakers with different sensitivities for every 3db increase in sensitivity it would take half the power to have the same volume ratio. Maybe I'm makng up a new term but by that I mean as you turn up the volume the gain would virtually be the same. For example, my DCM KX12 Series 2 speakers have a sensitivity of 99db. I think the sensitivity of my "lowly" Sony speakers are about 90db. With that logic with lets say a 100 watt amp the DCMs would be 8 times as loud. Okay that seems to be somewhat accurate when it comes amps with the same power and gain.

Now it is a different story altogether when you talk different amps with different voltage gains and an ability drive different amounts of current. In that case all bets are off. You might have very different results prior to clippage.
.Twice as loud is more like it. Read the link I provided in post # 17.

Robert-The-Rambler
11-23-2007, 08:57 AM
Twice as loud is more like it. Read the link I provided in post # 17.

Too much math to be thinking about here. <>__<>

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