250 Watts v 500 Watts

[Kevin Dean]

I was doing an A/B test the other day with my amps & something I noticed was that I couldn't tell any difference in volume between my MB little Rocker (500w) & the MarkBass Mo Mark 250 watt even when pushing them ..why would that be ?

[skidder652003]

something to do with wattage and decibels being linear...or something?.....doesnt the wattage have to be 10 times as big to just double the DB level, or am i talking tosh?

Edited November 18, 2014 by skidder652003

[Bill Fitzmaurice]

[quote name='skidder652003' timestamp='1416316514' post='2608929']
doesnt the wattage have to be 10 times as big to just double the DB level,
[/quote]It does. More accurately, it takes a 10dB increase to be perceived as a doubling of volume, which requires a tenfold increase in power.

[Noisyjon]

[quote name='skidder652003' timestamp='1416316514' post='2608929']
.....doesnt the wattage have to be 10 times as big to just double the DB level, or am i talking tosh?
[/quote]

I believe that's the case too and Alex's 'Mythbusters' info confirms this: [url="http://barefacedbass.com/technical-information/mythbusters1.htm"]http://barefacedbass.com/technical-information/mythbusters1.htm[/url]

[Noisyjon]

[quote name='Bill Fitzmaurice' timestamp='1416317995' post='2608963']
It does. More accurately, it takes a 10dB increase to be perceived as a doubling of volume, which requires a tenfold increase in power.
[/quote]

Beaten to it by Bill!

[chris_b]

I would want to know what cab was being used in this test.

[FuNkShUi]

So Bill, sorry if this is a slight derail, if you wanted a Amp with the most volume "out front", what measurement would you be looking at?
SPL?

[Kevin Dean]

[quote name='chris_b' timestamp='1416318205' post='2608969']
I would want to know what cab was being used in this test.
[/quote] Barefaced super 12T

[Tdw]

I think generally there should be a small difference in percieved volume between these outputs but not a very obvious difference

[uncle psychosis]

[quote name='FuNkShUi' timestamp='1416318496' post='2608974']
So Bill, sorry if this is a slight derail, if you wanted a Amp with the most volume "out front", what measurement would you be looking at?
SPL?
[/quote]

Its actually very hard to correlate perceived volume with measurements. SPL is not a bad place to start but even then the relationship between SPL and loudness isn't a simple one.

[url="http://en.wikipedia.org/wiki/Loudness"]http://en.wikipedia.org/wiki/Loudness[/url]

[xgsjx]

[quote name='uncle psychosis' timestamp='1416324126' post='2609060']
Its actually very hard to correlate perceived volume with measurements. SPL is not a bad place to start but even then the relationship between SPL and loudness isn't a simple one.

[url="http://en.wikipedia.org/wiki/Loudness"]http://en.wikipedia.org/wiki/Loudness[/url]
[/quote]
& then it's not so much what amp, but what cabs & drivers.
You could stick the same amp through an average 2x10 & then a better 2x10 and find the perceived volume difference to be huge.

[Guest monsterthompson]

[indent=1]doubling the wattage gets you 3db more in volume, if that is the only variable that is changed. however different amps have other different qualities. wattage is mainly about headroom. there have been endless internet arguments about how wattage isn't the only measurement for determining how "loud" an amp will be.[/indent]

[Bill Fitzmaurice]

[quote name='FuNkShUi' timestamp='1416318496' post='2608974']
So Bill, sorry if this is a slight derail, if you wanted a Amp with the most volume "out front", what measurement would you be looking at?
SPL?
[/quote]SPL is what you hear, not watts. There is no direct correlation between power and SPL. One can calculate the maximum SPl that a given amp and speaker combination will deliver if you have the required data, but no speaker manufacturer that I know of provides that data. If you know the T/S specs of the driver being used and have detailed cabinet dimensions you can calculate both the frequency response and maximum SPL of the speaker, but most speaker manufacturers won't tell you what the driver specs are.

[Musky]

[quote name='FuNkShUi' timestamp='1416318496' post='2608974']
So Bill, sorry if this is a slight derail, if you wanted a Amp with the most volume "out front", what measurement would you be looking at?
SPL?
[/quote]
And to add to what the others have said, it's worth bearing in mind that many manufacturers are... 'optimistic' with their specs.

A few years back when Alex pointed out that the specs quoted for a cab made by a respected manufacturer couldn't possibly true, said manufacturer did the decent thing, apologised and amended the specs. In mitigation they said they did it because all their competitors were lying as well...

[Bill Fitzmaurice]

[quote name='Musky' timestamp='1416355308' post='2609447']
A few years back when Alex pointed out that the specs quoted for a cab made by a respected manufacturer couldn't possibly true, said manufacturer did the decent thing, apologised and amended the specs. In mitigation they said they did it because all their competitors were lying as well...
[/quote]Aguilar, if I recall correctly. Eden was well known for blatently lying about their response and sensitivity specs when still being run by Dave Nordschow, and Nordschow continues to do so with his DNS line. Old habits die hard.

[Beer of the Bass]

[quote name='Musky' timestamp='1416355308' post='2609447']
And to add to what the others have said, it's worth bearing in mind that many manufacturers are... 'optimistic' with their specs.

A few years back when Alex pointed out that the specs quoted for a cab made by a respected manufacturer couldn't possibly true, said manufacturer did the decent thing, apologised and amended the specs. In mitigation they said they did it because all their competitors were lying as well...
[/quote]

Yes, I think most manufacturers do it. I have a small 1x10" which the manufacturers claim has 102dB sensitivity, 126dB max SPL and a usable frequency response down to 45Hz. I don't believe any of those for a moment!

[FuNkShUi]

[quote name='Musky' timestamp='1416355308' post='2609447']
it's worth bearing in mind that many manufacturers are... 'optimistic' with their specs.
[/quote]

Very kind choice of word. Hahaha

[Bill Fitzmaurice]

[quote name='Beer of the Bass' timestamp='1416397504' post='2609709']
Yes, I think most manufacturers do it. I have a small 1x10" which the manufacturers claim has 102dB sensitivity, 126dB max SPL and a usable frequency response down to 45Hz. I don't believe any of those for a moment!
[/quote]Technically all of that is possible. It could have a midrange peak at 102dB sensitivity, it could reach 126dB in the midrange, and it could have useable response to 45Hz, meaning that it's down 10dB from average at 45Hz. But that's all specmanship. There are specific rules set forthe by the AES as to how speaker measurements are to be made and quantified. Virtually every manufacturer ignores them.
One honest manufacturer is Ampeg, so they can be condsidered as the spec benchmark. When you see sensitivity and/or frequency response specs that are more than a couple of dB or Hz off from what a similar Ampeg product is rated at you can safely assume that the claims are bogus.

[chris_b]

On the other hand. . . . these optimistic, exaggerated or just plain false specs didn't stop Eden and many of the other makes sounding great.

I get that to many the paper work is important, but it's not as important as what the thing sounds like.

[xgsjx]

But the information given does matter.
I've get t a car that I really like. It has all the toys & tells you about these in the manual, but it also states the average MPG about 20 mpg above what it really is.
At the end of the day, that was one of the factors that I looked at & the marketing dept lied to me.
A lie is a lie even if they describe it as massaging the truth.

[Bill Fitzmaurice]

[quote name='chris_b' timestamp='1416404917' post='2609822']
On the other hand. . . . these optimistic, exaggerated or just plain false specs didn't stop Eden and many of the other makes sounding great.

I get that to many the paper work is important, but it's not as important as what the thing sounds like.
[/quote]I hear this argument over and over again, and it doesn't hold water. A lie is a lie. If you go to a butcher and order a pound of steak, and [i]pay[/i] for a pound of steak, and you actually get a 12 ounce steak, you were cheated, no matter how good the steak tasted.

[VTypeV4]

JBL quote (or used to at least) power compression specs for their components which I haven't seen from anyone else. They don't make bass guitar specific drivers or cabinets anymore however..

And for the O/P, 3dB (assuming both amplifiers are rated in the same way) isn't that noticeable..

[Musky]

[quote name='chris_b' timestamp='1416404917' post='2609822']
On the other hand. . . . these optimistic, exaggerated or just plain false specs didn't stop Eden and many of the other makes sounding great.

I get that to many the paper work is important, but it's not as important as what the thing sounds like.
[/quote]
I agree with you Chris, but in that case they shouldn't be putting [i]any[/i] specs up.

They're not going to do that though, as they know perfectly well that some people pore over the specs of various cabs to narrow down their choices, if not make their final decision. So instead they mislead or lie.

I seem to remember Alex found himself in a quandary regarding this when he started up Barefaced - how to honestly give the specs for his range without resorting to BS or making his cabs appear a poor relation to his competitors.

It doesn't make the blindest bit of difference to how the cabs sound, but it does for some people's purchase decisions.

[Bill Fitzmaurice]

[quote name='Musky' timestamp='1416438710' post='2610353']
It doesn't make the blindest bit of difference to how the cabs sound, but it does for some people's purchase decisions.
[/quote]It does, because if an Eden or DNS 410 actually had 106dB sensitivity then one of them would be as loud as two Ampeg 410s. If they weren't trying to give that impression to prospective buyers they'd not make the claim.
[quote]I seem to remember Alex found himself in a quandary regarding this when he started up Barefaced - how to honestly give the specs for his range without resorting to BS or making his cabs appear a poor relation to his competitors.[/quote]It is a difficult choice, which he probably handled in about as good a fashion as possible. Still, if it was me, I'd post measured SPL charts, and make it clear to prospective buyers why other manufacturers don't.