# THE $10,000 AMPLIFIER CHALLENGE



## jtroy (Mar 25, 2007)

Can YOU REALLY hear a difference between different amps? 

Recently ive seen many threads asking which amp, best amp, best budget amp etc.

A few weeks ago I came across this challenge at the Navone website

------------------------------------------------------------------
http://www.davidnavone.com/a2000/Amp%20challenge%202001%20Revision.pdf
THE $10,000 AMPLIFIER CHALLENGE RULES {revised May 28 , 2005}
By Richard Clark
There is no question that all amps are not the same. It is very easy to measure large differences in the performance of amplifiers. This is true in nearly every known specification, including power, noise, distortion, etc. My experience has led me to believe that even though these differences can be easily measured, hearing those differences may not be so easy. Given the relatively small magnitude of performance differences, there is a giant step between amplifier performance and our ability to hear performance differences.
It is claimed by designers, manufacturers and especially salespersons that differences in amplifiers are clearly audible. Reasons include "obvious" advantages of one type of circuit topology over another. For example, it is claimed that certain designs have a smoother midrange response whereas other amplifiers exhibit tighter bass. Tube fanatics claim that tube amplifiers have that "warm" sound we all need in our systems.
Such descriptive terms are certainly subject to personal interpretation. It is not my intention to determine if one particular amplifier is better than another amplifier. Differences in the quality of the discrete components and constructions are more appropriate for settling the issue of "good - better - best." The sole purpose of my amplifier challenge is to determine if the differences in amplifiers are audible.
What differences are Audible?
I believe the perceived differences in amplifiers are all due to various factors that can be explained with basic physics and elementary psycho-acoustics. For instance, if two amplifiers are not carefully matched in volume, and one amp is slightly louder than the other, then it would be a simple matter to detect such a difference. In such an example it is important to understand that it is not the circuit topology, quality of the component, design excellence, or superb marketing and packaging that caused the noticeable difference - it was an error in the test setup! It is my present belief that as long as a modern amplifier is operated within its linear range (below overload), the differences between amps are inaudible to the human ear.
Comparing Amps
The idea here is for a test subject to scientifically demonstrate his/her ability to hear differences in amplifiers. It is our job to carefully match the amps so that we are comparing "apples to apples" instead of "oranges to frogs." This means that we sure wouldn't want to compare one amplifier that had + 12 dB of high frequency boost against another amplifier that was adjusted for + 12 dB of bass boost. Such a test would be easy to pass - even on identical amplifiers with consecutive serial numbers.
For our comparison test, we aren't concerned with which amplifier sounds best to the test subject. We only require that the listener be able to identify each amplifier when it is powering the speakers. Since many folks seem to believe that amplifiers have some kind of distinctive sonic character, this test should be easy to pass. Right? After all, we're talking about comparing those harsh sounding, high distortion, squeaky "widget As" to those warm sounding, smooth, bass hog "widget Bs."
Now pay particular attention to the following sections. Since we're looking for differences in amplifiers, and we already know that those differences are probably going to be very, very small, it is important that the parameters under our control be carefully adjusted so as to be equal as possible. This means that we must be cognizant of differences we might unknowingly introduce between amp A and amp B. They must be adjusted as identical as possible. We already mentioned the importance of volume. The same goes for the L and R balance. It sure would be easy to choose an amplifier that exhibited left side bias over a balanced amp. Right?
Well, in order to keep this amplifier comparison test fair, there are a few other parameters that must be considered. I'll list them all in the following section.
Amplifier Comparison Test Conditions
1. Amplifier gain controls - of both channels - are matched to within +- .05 dB.
2. Speaker wires on both amps are properly wired with respect to polarity. (+ and -)
3. That neither amp has signal phase inversion. If so correction will be made in #2 above.
4. That neither amp is loaded beyond its rated impedance.
5. That all amplifiers with signal processors have those features turned off. This includes bass boost circuits, filters, etc. If frequency tailoring circuits cannot be completely bypassed an equalizer will be inserted in the signal path of one of the amps (only one and the listener can decide which) to compensate for the difference. Compensation will also be made for input and output loading that affects frequency response. Since we are only listening for differences in the sonic signature of circuit topology, the addition of an EQ in only one amps signal path should make the test even easier.
6. That neither amp exhibits excessive noise (including RFI).
7. That each amp can be properly driven by the test setup. Not normally a problem but it is theoretically a problem.
8. That the L and R channels are not reversed in one amp.
9. That neither amp has excessive physical noise or other indicators that can be observed by the listener.
10. That neither amp has DC OFFSET that causes audible pops when its output is switched.
11. That the channel separation of all amps in the test is at least 30 dB from 20Hz to 20kHz.
Page 1 of 2
----------------------------------------------------------------


I know many people (including myself) like to think there are plainly audible differences between amplifier brand X and brand Y.....Richard Clark doesnt think so....is he right? IF you disagree would you take that challenge?


----------



## jearhart (Jul 28, 2006)

pretty sure everybody on this site has heard of it. and there have been multiple threads arguing about it.

i will not give my opinion on it as to not start a war. but im sure it will happen


----------



## ca90ss (Jul 2, 2005)

werewolf said:


> Any amp with adequate power, low in noise and distortion, will be indistinguishable from any other.


----------



## sqkev (Mar 7, 2005)

read the rules carefully

5. That all amplifiers with signal processors have those features turned off. This includes bass boost circuits, filters, etc. If frequency tailoring circuits cannot be completely bypassed an equalizer will be inserted in the signal path of one of the amps (only one and the listener can decide which) to compensate for the difference. Compensation will also be made for input and output loading that affects frequency response. Since we are only listening for differences in the sonic signature of circuit topology, the addition of an EQ in only one amps signal path should make the test even easier.



PLUS..sonics is something that is hard to remember
when you're going back and forth between 2 of the very same sound (assuming both amps(or 1) are equalized to play flat) your ears become so fatigue that you can't distinguish the slight differences.


----------



## jtroy (Mar 25, 2007)

ca90ss said:


>


A factor ive never taken into account is that high end brand X may be seriously underated compared to cheap brand Y which may be overated in RMS output.


----------



## 60ndown (Feb 8, 2007)

$10,000 tweeters definately have better sound.























































nah! jus kiddin


----------



## FoxPro5 (Feb 14, 2006)

Yawn....sigh.....here we go again......

Glad I have Rampage amps at times like these.


----------



## npdang (Jul 29, 2005)

I don't think anyone ever, ever said that all amps sound the same. The debate is whether or not it's worth paying for those differences.


----------



## Guest (May 11, 2007)

You won't win the challenge.

If you _really_ understand what the challenge is saying about what contributes to the "sound" of amplifiers ... and equally important, what _doesn't_ contribute to the "sound" of amplifiers ... you'll understand why.

Please do us all a favor, in this thread at least. Don't make the blatantly STUPID assumption that the challenge says that "all amps sound the same", or that the challenge says that "a watt is a watt." If you think the challenge can be captured by either of these simple-minded synopses, you really don't understand the challenge at all.


----------



## jtroy (Mar 25, 2007)

sqkev said:


> read the rules carefully
> 
> 5. That all amplifiers with signal processors have those features turned off. This includes bass boost circuits, filters, etc. If frequency tailoring circuits cannot be completely bypassed an equalizer will be inserted in the signal path of one of the amps (only one and the listener can decide which) to compensate for the difference. Compensation will also be made for input and output loading that affects frequency response. Since we are only listening for differences in the sonic signature of circuit topology, the addition of an EQ in only one amps signal path should make the test even easier.
> 
> ...


IF the differences are slight is it worth it to pay hundreds more for a higher end brand/model?


----------



## 60ndown (Feb 8, 2007)

npdang said:


> I don't think anyone ever, ever said that all amps sound the same.


i do  



a good amplifier 'should' only amplify the signal, 

zero colouration, 

if it colors at all, 

its not a 'good' amp.

and therefore, all 'good' amps sound the same.


----------



## effenay (Mar 2, 2006)

Welcome to 10+ years ago.

This thread will be most useful if everyone would *please* read the FAQ and complete rules before posting.

Richard Clark $10,000 Amplifier Challenge FAQ:
http://www.tom-morrow-land.com/tests/ampchall/


----------



## 60ndown (Feb 8, 2007)

jtroy said:


> IF the differences are slight is it worth it to pay hundreds more for a higher end brand/model?


depends how small your penis is.


----------



## jtroy (Mar 25, 2007)

lukeboa said:


> depends how small your penis is.



Well then.....im off to buy some Pyramid amps.


----------



## Guest (May 11, 2007)

lukeboa said:


> i do
> 
> 
> 
> ...


so you can't tell if two identical amps, from the same production run, have their _gain knobs_ set at the two different extremes? One amp with gain maximized, the other with gain minimized?

If you answer by saying ... "well, of course i assume that the GAINS are set the same, to within the limits of human hearing" ... welcome to your first step down a path we call the scientific method


----------



## ca90ss (Jul 2, 2005)

I don't think any one is saying that all amps sound the same. The question that should be asked is what makes them sound different (differences in gain, frequency response, power, noise and distortion).


----------



## Guest (May 11, 2007)

ca90ss said:


> I don't think any one is saying that all amps sound the same. The question that should be asked is what makes them sound different (differences in gain, frequency response, power, noise and distortion).


we have a winner 

Consider whether the challenge says, or rather hypothesizes :

- _All amps sound the same_

or :

- _Any and all "sonic signatures" of amplifiers can be attributed to : power, gain, frequency response, noise and distortion._

Are these statements the same? Which one more accurately captures the challenge?


----------



## ca90ss (Jul 2, 2005)

werewolf said:


> Are these statements the same?


No



> Which one more accurately captures the challenge?





> _Any and all "sonic signatures" of amplifiers can be attributed to : power, gain, frequency response, noise and distortion._


----------



## zukiaudio (Jan 31, 2007)

http://www.answers.com/topic/challenge


----------



## ArcL100 (Jun 17, 2005)

jtroy said:


> A factor ive never taken into account is that high end brand X may be seriously underated compared to cheap brand Y which may be overated in RMS output.


Arc, McIntosh, all that **** is only slightly underrated from what I've seen - just like the more modestly priced stuff out there. You have to go back to old RF and stuff like that to get seriously underrated.



jtroy said:


> IF the differences are slight is it worth it to pay hundreds more for a higher end brand/model?


If you want to impress the locals or have an impressive forum sig...

-aaron


----------



## jtroy (Mar 25, 2007)

ArcL100 said:


> Arc, McIntosh, all that **** is only slightly underrated from what I've seen - just like the more modestly priced stuff out there. You have to go back to old RF and stuff like that to get seriously underrated.
> 
> 
> 
> ...



Ok thanks.... i think that was the meat and potatoes of what we want here.


----------



## Whiterabbit (May 26, 2006)

or, you know. An amp that may or may not have significant gain hiss, delays turning off so long that your stereo has problems with turn on or turn off pops, things of that nature.

There's more to life than how an amp sounds. Or doesnt sound. theres integration, too! The thing has to OPERATE as well as FUNCTION!


----------



## Vestax (Aug 16, 2005)

RC rules.. All amps sound the same!


----------



## Whiterabbit (May 26, 2006)

o'doyle rules.......o'doyle rules.......o'doyle rules......o'doyle rules.....

I gave peter an install idea for the diyma in the trunk, and you damn well better listen!

I also recommended the 701 to go to the left and the amplifiers in the back because of how clean the wiring is compared to the othre way around.

Also, I have a bunch of cabletrack used for rackmount servers. I have I think 18 feet of it in various sizes. you need any or want to use any, call me.


----------



## MarkZ (Dec 5, 2005)

sqkev said:


> PLUS..sonics is something that is hard to remember
> when you're going back and forth between 2 of the very same sound (assuming both amps(or 1) are equalized to play flat) your ears become so fatigue that you can't distinguish the slight differences.


Can you elaborate? I don't know what that means.


----------



## MarkZ (Dec 5, 2005)

npdang said:


> I don't think anyone ever, ever said that all amps sound the same.


I did.

Well, except for the ultra-expensive exotic high-distortion amplifiers. But you don't really find those in car audio.


----------



## Hillbilly SQ (Jan 26, 2007)

i ran a sony xm2150 for years. it was my first amp and a NEVER had any problems with it. couldn't ask for a more reliable amp even after getting hot enough to fry eggs on day-in and day-out. in a direct comparison between a us acoustics usx2150 and memphis mc300 there was almost no audible difference. with the onboard crossover in each amp used, there were differences but i can't remember which sounded better. the one control was ALL 3 AMPS WERE RATED 150RMS PER CHANNEL. in my eyes, i could care less what kind of amps i'm running as long as they do at least rated power, fit the install, and are reliable.


----------



## 89grand (Nov 23, 2006)

Well, for instance I have PPI Art Series amps in my Jeep and everybody raves about those, and I have JBL GTO series amps in my Crown Vic, and some people that like to talk out of their asses have claimed those amps suck.

I can't tell them apart and I'm sure no one else can either. My PPI A600.2 was $579, more than both of my JBL amps combined, and there is no difference that I can tell.


----------



## DonutHands (Jan 27, 2006)

but on the other hand, there are huge sonic differences in speaker wire and interconnects. just go read some posts on headfi.org


----------



## Guest (May 11, 2007)

let's have some fun ...

For anyone who suggests (or stupidly misrepresents RC's Amp Challenge) that "*all amps sound the same*", here's my challenge:

1. Get a 10 watt amp and a 1000 watt amp, drive your favorite low-efficiency, monster sub with each ... at reasonable volume levels. Notice a difference?

Now if you have even a fraction of a brain cell, at this point you should be saying something lke :

"*Well of course I mean amps of similar power rating operating below clipping.*"

2. Now get two _identical_ amps, but turn the gain knob all the way down on one amp, all the way up on the other. I'll bet you can hear a difference ... and easily distinguish one from the other a thousand times in a row ... even when driving the exact same speakers, with the exact same input signal. Guess what we've just shown, once again? All amps DO NOT sound the same ... how about that!

At which point you should be thinking :

"*Well of course I mean amps of similar power rating operating below clipping, with gains adjusted to be the same under the threshold of human hearing.*"

See where this is going?

The amp challenge does NOT suggest that ALL amps sound the same. As we've seen, that's an hypothesis which is stupid-simple to _disprove_. Instead, the amp challenge puts forth the following hypothesis :

*Any sonic signature of an amp can be attributed to power, gain, frequency respnse, noise and distortion.*

The amp challenge is designed to DISPROVE this hypothesis, by listening for any "residual" sonic differences after these parameters have be equated.

So far, the hypothesis remains standing.


----------



## MarkZ (Dec 5, 2005)

werewolf said:


> 1. Get a 10 watt amp and a 1000 watt amp, drive your favorite low-efficiency, monster sub with each ... at reasonable volume levels. Notice a difference?
> 
> Now if you have even a fraction of a brain cell, at this point you should be saying something lke :
> 
> "*Well of course I mean amps of similar power rating operating below clipping.*"


I thought it was a given that the discussion was about amps operating within the constraints that they were designed to be operated under? How does an expensive McIntosh amp sound driving a 1/2 ohm load at full throttle?



> The amp challenge does NOT suggest that ALL amps sound the same. As we've seen, that's an hypothesis which is stupid-simple to _disprove_. Instead, the amp challenge puts forth the following hypothesis :
> 
> *Any sonic signature of an amp can be attributed to power, gain, frequency respnse, noise and distortion.*
> 
> ...


I think you're the one that's oversimplifying the challenge, werewolf. The implication is quite clearly that all amps sound the same (or, perhaps more accurately, _can be made to sound the same_). As you said, he's simply implementing controls to make sure that differences don't present themselves in the form of simple amplitude differences or differences introduced by signal processing. But don't lose sight of what it was that brought this challenge to fruition.

When someone says "all car amplifiers sound the same", it should be obvious that they're not saying that two amplifiers with different signal processing settings and playing a speaker at different volume levels will sound the same. That's never been the debate.


----------



## Guest (May 11, 2007)

MarkZ said:


> I thought it was a given that the discussion was about amps operating within the constraints that they were designed to be operated under? How does an expensive McIntosh amp sound driving a 1/2 ohm load at full throttle?
> 
> 
> 
> ...


Science demands precision, not unspoken assumptions. And i sure wouldn't put my $10K on the line, without exacting terminology.

And I'm not oversimplifying anything. It's a GROSS ... and obviously incorrect ... oversimplification to suggest that all amps sound the same. It's an hypothesis that ridiculously easy to disprove.

The challenge came into existence to demonstrate that typical audiphile claims about exotic solder, wire, etc. have no foundation. If the architecture, parts selection, build technique etc. do not materially impact the standard parameters of gain, power, frequency response, noise and distortion ... then they no not impact the "sound." That's not an oversimplification.

Allow me to ask ... WITHOUT qualification ... do you still believe that all amps sound the same? Please answer in the context of a scientific test (which simply controls variables in order to _isolate_ and _measure_ them) ... which the RC Challenge surely is.


----------



## thehatedguy (May 4, 2007)

I thought the history of the test came from RC trying to isolate WHAT caused amps to sound different. I was pretty certain that when the test first was started, he acknoldged that amps do sound different, or atleast there were changes to the sound being caused by the amps- be it FR differences, level differences, phasing, etc.


----------



## fej (Feb 8, 2006)

Ahh the amp challenge being brought back from the dead ...

Simple answer, with enough variables either controlled or eliminated it is very easy to prove your hypothesis in pretty much any arguement. RC controls everything needed to make the challenge fool proof.

I would venture to say that at least 90% of this board has read about this, read threads about this, and understands what this test was/is.

I think it is funny. IMO you pay more for advertised + watts on amps, and occasionally the level of features built in, not for "sound".


----------



## Guest (May 11, 2007)

... by the way, the simple fact that two amps with different volume settings (through different gain settings) and different frequency responses (through bass boost, eq, etc.) will sound different ... is the very heart of the debate.

Many people believe there to be mysterious amplifier "sonics" that _cannot_ be atributed to volume, gain, power and frequency response. It's the very essence of the challenge ... and therefore, the debate ... that once any differences in these parameters are removed, then amplifiers become indistinguishable. If the differences are _not_ removed, then amplifers sound different. It is the very essence of the challenge.

Which is why is clearly erroneous to believe the challenge to suggest that "all amps sound the same." In fact, the challenge states the exact opposite ... amplifiers sound different, but the reasons are COMPLETELY captured in power, gain, frequency response, noise and distortion.


----------



## DonutHands (Jan 27, 2006)

i think most of us understand what you are saying werewolf. at the core of it a watt is a watt. its just setting up the amps to be on an even playing field that will show us this.


----------



## FoxPro5 (Feb 14, 2006)

MarkZ said:


> The implication is quite clearly that all amps sound the same (or, perhaps more accurately, _*can be made to sound the same*_).


BINGO!!

Amps that measure the same, sound the same.

RC set out to call BS on companies like JL who were claiming sonic superiority for various marking reasons. It's called a "challenge" because the manufacturers know full well that all amps CAN BE MADE TO SOUND THE SAME. Now if you want to drop loads of cash for the other features that are important in amplifier selection, then by all means. In the mean time, forget the idea of spending any extra for sonics.


----------



## FoxPro5 (Feb 14, 2006)

internecine said:


> i think most of us understand what you are saying werewolf. at the core of it a watt is a watt. its just setting up the amps to be on an even playing field that will show us this.


Amps that test the same, sound the same...according to RC and Werewolf's hypothesis. He never said a watt is a watt...nor did RC.


----------



## chadillac3 (Feb 3, 2006)

I really don't think the target was JL...


----------



## chadillac3 (Feb 3, 2006)

B-Squad said:


> Amps that test the same, sound the same...according to RC and Werewolf's hypothesis. He never said a watt is a watt...nor did RC.


Well, a watt IS a watt.


----------



## FoxPro5 (Feb 14, 2006)

chadillac3 said:


> I really don't think the target was JL...


My bad, they do sound better...that's right.  Must be why I said LIKE (as in, for example) JL.  My point is that RC is pro-consumer tr, anti-manufacturer hype. I can't believe how diluted the whole thing has become. It's sad.


----------



## chadillac3 (Feb 3, 2006)

Couldn't agree more there. RC is actually fighting "the man" and everyone tries to tear him down.


----------



## MarkZ (Dec 5, 2005)

werewolf said:


> Science demands precision, not unspoken assumptions. And i sure wouldn't put my $10K on the line, without exacting terminology.
> 
> And I'm not oversimplifying anything. It's a GROSS ... and obviously incorrect ... oversimplification to suggest that all amps sound the same. It's an hypothesis that ridiculously easy to disprove.
> 
> ...


If you asked me instead whether or not I believed that all speaker wire sounds the same, I would answer yes it does. The problem comes when you adhere to a strict definition of the phrase, rather than taking into account the context in which it was used. So even though I say all speaker wire sounds the same, I'll readily admit that if you compare a run 12 inches long with one 12 miles long; or one that's corroded to hell (or even broken) vs. one that isn't; or one that (for some unknown reason) is terminated by 100 ohm resistors, then obviously they wouldn't sound the same. When you ask someone to say something "without qualification", you're pretty much by definition oversimplifying the issue. Without qualification? -- yes, interconnects sound different, amplifiers sound different, and just about everything else in the world that we consider absolute doesn't mean jack. But in the real world there are always qualifications, and for good reason.

If you're asking me if I think that all amps that measure the same sound will the same, you know my answer to that. But I don't think that gets at the crux of the issue that's so often raised in this forum (in this thread, even!), and that's whether amps have a "sonic signature". Even after you get somebody to acknowledge that amps that measure the same sound the same, you're still faced with the question of whether amps sound the same (or _can be made to sound the same_, within their operating limits). And that was the issue that npdang addressed earlier, and the one that I disagreed with him on.


----------



## Thoraudio (Aug 9, 2005)

what should be most telling is the deafening silence from the 'high-end' manufacturers.... or more tellingly, the lack of action.

If I were from Tru or Arc or Phass or whoever, and honestly believed my amps sounded better, and made my livelihood based on them sounding better, I'd be at R.C.'s or D.N.'s place in a second to take and document the test. 

There are three options to this result.

1. I/my representative wins, and I get lots of good free press.

2. I/my rep loses, but in doing so, I demonstrate out that R.C. is a fraud, and the amps were manipulated in some fashion.

3. I/my rep loses, and I go about selling my amps for reasons other than magic s.q. 

But, unfortunately, everybody in the amp making business is to busy.


----------



## npdang (Jul 29, 2005)

A watt is a unit of measurement... it's like saying a pound of grass is the same as a pound of dirt.

But I have to ask, can the average person make one amp sound like another? It's doubtful Imho... and to some people it's worth it to pay for that difference in sound regardless.


----------



## chadillac3 (Feb 3, 2006)

npdang said:


> A watt is a unit of measurement... it's like saying a pound of grass is the same as a pound of dirt.
> 
> But I have to ask, can the average person make one amp sound like another? It's doubtful Imho... and to some people it's worth it to pay for that difference in sound regardless.


From what I remember about reading some of RC's posts back in the day, all he usually had to do was bypass internal processing and level match very exactly...not too hard. Now if you're implying making sure a person has a very steady supply of power to the amps, that would probably be more of an issue.


----------



## Luca_Bratzi (Mar 9, 2007)

Where do Tube amps stand regarding this subject?

Although I have never owned a tube amp, I have read many opinions from poeple who claim they have a different "Warmer" sound. From what I have seen from the research it may be from the interpretation of added noise or even from an apparent cut in higher frequencies that may contribute to this sound?


----------



## badlieu (Jul 13, 2005)

Luca_Bratzi said:


> Where do Tube amps stand regarding this subject?
> 
> Although I have never owned a tube amp, I have read many opinions from poeple who claim they have a different "Warmer" sound. From what I have seen from the research it may be from the interpretation of added noise or even from an apparent cut in higher frequencies that may contribute to this sound?



I recall RC saying that he could add $3 in parts to any SS amp to make it sound or perform like a tube amp.

I dug up two quotes -



> of course my challenge includes tube amps---thats what got it started to begin with----while most tube amps have more distortion than transistor amps it is still usually below the audible level of a couple percent---the biggest audible difference is like Big T said---the higher output impedance created by the transformer windings causes a slight frequency dependant amplitude difference---while this is usually less than a db or so except in the worst designs (the "super" amps without negative feedback really have this problem big time)the effect is subtle but audible-----and since it naturally happens at the resonant places of the speaker it is sometimes very pronounced----it is easily duplicated with a small value resistor in series with the speaker-----RC-





> Blkout---tube amps are a serious waste of money--an obsolete technology like wooden wheels and horse drawn buggys-i can make any good quality solid state amp sound exactly like a tube amp with less than 5 dollars worth of parts---i have done it on many ocaasions for my amp challenge---but why would anyone want to degrade a good solid state amp to make it sound like a tube unit??? sure confuses me...........RC


----------



## cvjoint (Mar 10, 2006)

I dont' understand one thing. I believed most people on this forum hold the ideea that a metal cone cannot be eq'ed to sound like a paper cone true. Why doesn't this hold for amplifiers?

In other words my belief is: there are things out there that might not be depicted on the graph, and there IS a sonic fingerpring for any music related device (whether it being an amp, speaker, wire etc.) No, I cannot prove it.

Therefore: what the challenge is trying to prove is that the differences cannot be picked up by the human ear, and are beyond what existing techonology can test for.

The result can be used as follows: For any practical purpose, amps *can* be made to sound the same. No one goes to such lengths to make them that way, -- premium amplifiers and demand for them will always exist.


Nothing changed in the world after the amplifier challenge:

1. people that believe in amp fingerprints can still argue that way (I still do)

2. people that were swayed by the test are still willing to buy a high price/high quality amp. because *"power, frequency response, noise and distortion"* variables look much better in these models/cannot be had from a $50 flea market amp/equalizers and filters needed to make all amps sound the same will add some sonic fingerprint/distorition as well.

The difference in between people from category one and two is that sonic fingerprint will only be taken into account by the first group, but in the greater picture it does not matter, we all want better/more expensive amplifiers with better power, freq. resp. etc.


----------



## npdang (Jul 29, 2005)

You can't compare an amp to a speaker... they are 2 completely different things.

If you look at the types of corrections used to make one amp sound like another, then ask yourself are these differences worth paying for?


----------



## erickoh (Mar 6, 2006)

so is there a $3 tweak to convert tubes back to SS again?


----------



## MarkZ (Dec 5, 2005)

cvjoint said:


> I dont' understand one thing. I believed most people on this forum hold the ideea that a metal cone cannot be eq'ed to sound like a paper cone true. Why doesn't this hold for amplifiers?


You can EQ just about anything to sound like anything else if the only parameter differed was frequency response. In practice this becomes more difficult because EQs lack infinite resolution. This is especially difficult with speakers because their FRs don't always follow a well behaved trend. With signal processors (in amplifiers, for example), it becomes much easier -- you simply provide the inverse of whatever the processor is doing. So if the amp has a 40Hz bass boost with a certain Q and level, then you can cancel it with a 40Hz bass cut with the same Q and level. Or you can just defeat or remove the bass boost circuit to begin with. Not so easy with speakers, especially when they have a freq response that looks like a roller coaster!

The other major factor can be summed up with one word: distortion. Not just the magnitude, but the actual content (the "sonic signature" if you will ). Distortion is considerably higher in speakers than it is in non-clipping amplifiers. Quite frankly, distortion can be considered to be nil in modern solid state car amplifiers. Therefore, it's another factor that has to be corrected in speakers but doesn't even appear in amplifiers.



> In other words my belief is: there are things out there that might not be depicted on the graph, and there IS a sonic fingerpring for any music related device (whether it being an amp, speaker, wire etc.) No, I cannot prove it.
> 
> Therefore: what the challenge is trying to prove is that the differences cannot be picked up by the human ear, and are beyond what existing techonology can test for.


And this is the issue that werewolf is getting at -- amps that measure the same will sound the same. This is because the entirety of a signal of any type (electrical, acoustical, whatever) can be completely represented by its spectral components. That is, we can fully characterize a signal mathematically and then make comparisons quantitatively using a number of parameters to describe the signal. Granted, the behavior of a device may not be constant across all conditions -- maybe it'll change with temperature, power output, speaker load, etc. But if that's so, we would be able to capture that change from a measurement standpoint. It's not a technology bottleneck -- we have the capability to measure voltage and current with incredible precision that far surpasses anything that could be picked up by the human ear (after it's transformed into an acoustic signal, of course).



> Nothing changed in the world after the amplifier challenge:
> 
> 1. people that believe in amp fingerprints can still argue that way (I still do)
> 
> ...


There's a third group of people who buy amplifiers because of other factors, and don't believe that there exists an appreciable difference in "frequency response, noise, and distortion" between the vast majority of amplifiers on the market. I'm in that group. Do I buy cheapo amps? Not usually. I just bought a Zed Audio Minilith from someone on this board. Why did I choose it? Build quality (ie. reliability), looks, power rating, availability of service, and size. It had absolutely nothing to do with sonic characteristics. I also didn't look at a single response graph or spec sheet, and wouldn't even if I was considering a less reputable amp. That stuff just doesn't make any difference in today's equipment.


----------



## kappa546 (Apr 11, 2005)

i dont really know where i stand with the whole challenge. obviously people don't go through all that when using amplifiers, they just set gains and run. my thought is that even following all the challenge clauses, on a big efficient rig (think edgar horns or something) there would be a noticeable difference in terms of dynamics an amp can produce between say a strictly regulated JL 300/2 (i'm not a fan of jl amps btw) and say the monstrous adcom 4702 with the separate PS chassis or even one of my beefy 2.2HV's. i don't care if they are exactly gain matched and processing bypassed (adcom and LP have none btw), those two would walk all over the jl. i would love to see that exact amp-off actually.


----------



## FoxPro5 (Feb 14, 2006)

chadillac3 said:


> Well, a watt IS a watt.


Right, sorry. It's an amplifier, not a wattifier.


----------



## Guest (May 11, 2007)

you guys are all crazy .... 

Yes, I've always felt that, since the american public needs simple catch phrases so as not to exceed their limited attention span (ok i'm in a pissy mood), it's more accurate to summarize the challenge by saying : 

*All amps that measure the same, sound the same.*

The statement needs no further qualification, only an explanation as to what measurements are important. But the RC Challenge provides that very answer, by CLEARLY demonstrating what parameters need to be equal, for two amps to be sonically indistinguishable. Nothing else matters, as far as "amp sonics" are concerned.

Yes, this IS a service to the buying public ... because it really filters out bogus marketing claims.

Regarding speakers, things are not so easy. I've always maintained that the simple reason is ... more dimensions  With amplifiers, you've got only one important dimension : TIME. It's the only independent variable, the only "axis" of concern. Voltage vs. time, is all an amplifier can do. Sure, you've also got the frequency domain, but that is precisely NOT independent of what's happening in the time domain. For example ... two amps with the same bandwidth (and roll-off characteristics) will have exactly the same transient rise time. The amps have no choice.

With speakers, you have the added variable of SPACE. Space along the surface of the cone, space in the listening room in three dimensions, etc. It's simply much harder to "equlaize" a small set of parameters. Doesn't mean it's impossible, just a more complex problem.

Finally, to everyone who believes "a watt is a watt", here's a question :

Will a 1kHz _sinewave_, delivering EXACTLY one watt of power to a loudspeaker, sound indistinguishable from a 1kHz _squarewave_, also delivering EXACTLY one watt of power to the same loudspeaker? Clearly the answer must be a resounding YES ... if all "watts" sound the same 

Hope you guys all know MarkZ and i are _not_ disagreeing ... it was my honest hope that debating in this fashion ... adopting a strong position ... would help illuminate, perhaps even educate


----------



## MIAaron (May 10, 2005)

hogwash

Watts r watts. All amps sound the same!!!


----------



## Hobbes26 (Mar 9, 2005)

How difficult is it to actually do the test?

What do we need, in order to do the basic test with just gain matching between amps?

Turn off all bass boost, etc on amps.
Use test tone (@ 1kHz?) to set output gain on amps to same voltage
Connect speakers and listen...

Listening under double-blind conditions is necessary, so you gotta get a few buddies to help out...

Anything I'm missing?


----------



## Guest (May 11, 2007)

Hobbes26 said:


> How difficult is it to actually do the test?
> 
> What do we need, in order to do the basic test with just gain matching between amps?
> 
> ...


not really ... but you really do want to measure the frequency response WITH the speaker load connected (nothing much more than gain at a few frequencies) to make sure you're not hearing an "unexpected" EQ 

Might be surprised to find a few dB boost here and there, even with boost and eq circuitry set "flat".


----------



## Abmolech (Nov 2, 2006)

Good to see this debate gain.

It is important to grasp what the information is revealing, and almost as important, the variables.

If somebody "rates" a speaker as "great"

what does this reveal and how does this help us?

Scientific thought process is designed to limit the variables to "one" in an ideal test. In this case the only variable must exist outside that of the control experiment.
Can we measure the differences between one amplifier and another if the variables in RC challenge is met? 

With ease.

Can we do it with our auditory system on music?
So far, none have succeeded.

While this test has "liberated" some of us from "interesting" marketing claims, the greatest gift is the ability to apply similar concepts to other "choices".
Although perhaps Newton should take that crown.


----------



## Mr Marv (Aug 19, 2005)

Hobbes26 said:


> How difficult is it to actually do the test?
> 
> What do we need, in order to do the basic test with just gain matching between amps?
> 
> ...


It's not quite that simple. In our "test" we found that some amps had bass boost at a certain frequency _even when it was switched off_, variations in left/right output as well as other frequency response variations.


----------



## Guest (May 11, 2007)

Abmolech said:


> Good to see this debate gain.
> 
> It is important to grasp what the information is revealing, and almost as important, the variables.
> 
> ...


Remember that in _some_ cases (if not all ...), simple LOGIC reigns supreme.

For example, you don't need to understand anything about the human auditory system (including ears, brain, emotion, etc.) to understand that if two amplifiers deliver identical voltage to the loudspeaker terminals, then the speaker has no choice but to respond identically. If you're convinced that you hear otherwise ... but are unable to prove it, or demonstrate it ... you've been fooled  pure and simple.


----------



## ArcL100 (Jun 17, 2005)

I want a double blind driving down a Michigan highway in an ordinary installed 2-way car test, k thnx 

-aaron


----------



## Guest (May 11, 2007)

Mr Marv said:


> It's not quite that simple. In our "test" we found that some amps had bass boost at a certain frequency _even when it was switched off_, variations in left/right output as well as other frequency response variations.


that's what i'm talkin' about !!!!


----------



## kappa546 (Apr 11, 2005)

Mr Marv said:


> It's not quite that simple. In our "test" we found that some amps had bass boost at a certain frequency _even when it was switched off_, variations in left/right output as well as other frequency response variations.


well i'll tell you what. why dont we add this to the itinerary for the bbq? there will be a huge range of amps available and i'd even bring my LP. i dont disagree with the theory, but since when does a hypothesis stand as truth by itself? the main question i want answered is the regulated vs. unregulated.

come to think of it it's probably easier for werewolf and i to run the test locally lol. i'm sure you have a few amps laying around


----------



## Mr Marv (Aug 19, 2005)

kappa546 said:


> well i'll tell you what. why dont we add this to the itinerary for the bbq? there will be a huge range of amps available and i'd even bring my LP.


This argument has been going on forever and I find a _lot_ of people don't _truly understand_ what the "challenge" is trying to prove so I wouldn't waste time doing that at the BBQ because IMO it will not settle anything. 



kappa546 said:


> i dont disagree with the theory, but since when does a hypothesis stand as truth by itself? the main question i want answered is the regulated vs. unregulated.


I havn't heard of anyone collecting 10g's to prove the "theory" is incorrect.  Also, if you do a "true scientific test" it won't matter if it's regulated or unregulated since _all other variables must be removed_ (ie: each amp must play at the same level within the unclipped limits of the "lesser power" amp").


----------



## kappa546 (Apr 11, 2005)

i definitely understand what the challenge is about. just thought it might be fun and it would answer a question for me. also, i never said anything about higher or lower power amps... i understand the conditions of the test. my curiosity lies behind all other things being equal, how will an unregulated amp perform next to a regulated. anyways, whatever we can let this die


----------



## kappa546 (Apr 11, 2005)

just to clarify a bit, i'm not suggesting the amps will still add a signature to the sound... i'm concerned with how well it will handle highly dynamic music which would definitely make a difference. i don't think that's outside the experiment at all


----------



## jtroy (Mar 25, 2007)

Interesting...I turn around and this thread went ballistic  

I read through the amp challenge FAQ and RCs original comments as well as 38 pages of posts.....whew!

I used to be a big believer in Amp sonics mumo jumbo but if anything im quite relieved now that I know that I dont have to pay a fortune for a decent amp.


----------



## Abmolech (Nov 2, 2006)

> I used to be a big believer in Amp sonics mumo jumbo but if anything im quite relieved now that I know that I dont have to pay a fortune for a decent amp.


This poses some serious questions.

How do we the (poor informed) consumer decide how to purchase a power amplifier? Reliability, fit for the task, support and warranty may all be valid criteria. Still we are often limited to public opinion for a number of these.

If the marketing department is so untrustworthy, who can/should champion the cause for the consumer.

"caveat emptor"


----------



## jtroy (Mar 25, 2007)

Abmolech said:


> This poses some serious questions.
> 
> How do we the (poor informed) consumer decide how to purchase a power amplifier? Reliability, fit for the task, support and warranty may all be valid criteria. Still we are often limited to public opinion for a number of these.
> 
> ...




You can never trust any marketing department....lest we believe that a pill will give you a huge penis or drinking the right beer will get you more women.


----------



## MiniVanMan (Jun 28, 2005)

jtroy said:


> You can never trust any marketing department....lest we believe that a pill will give you a huge penis or drinking the right beer will get you more women.


You say that sarcastically. Why? Oh wait, don't tell me..


AAAAAHHHHH, CRAP!!!


Let's also remember what the definition of "Audiophile" really is.

'Audiophile' - One who claims to hear what the rest of the human population can't.

I'm not saying that some people are not more sensitive than others when it comes to certain tones, timbres and frequencies. I'm saying that 99% of the people that have uber expensive amps couldn't tell the difference between their amp and one costing half as much.


----------



## thehatedguy (May 4, 2007)

It this was closer to me, I could bring a stock LP, a modded LP 3.2, Brax X2000, Brax Graphic X2000, a Brax Graphic X2400, a HSS Fidelity HV230 Class A all tube amp, and maybe my Milbert BAM235 (it's on loan).


Probably could borrow a JL 300/4, a Boston 4 channel, a Memphis PR series 2 channel, and maybe borrow a Genesis DMX from a buddy. 


That's just what I have on hand at the moment at my house.


----------



## kappa546 (Apr 11, 2005)

show off


----------



## Mr Marv (Aug 19, 2005)

kappa546 said:


> i dont really know where i stand with the whole challenge. obviously people don't go through all that when using amplifiers, they just set gains and run. my thought is that even following all the challenge clauses, on a big efficient rig (think edgar horns or something) there would be a noticeable difference in terms of dynamics an amp can produce between say a strictly regulated JL 300/2 (i'm not a fan of jl amps btw) and say the monstrous adcom 4702 with the separate PS chassis or even one of my beefy 2.2HV's. i don't care if they are exactly gain matched and processing bypassed (adcom and LP have none btw), those two would walk all over the jl. i would love to see that exact amp-off actually.





kappa546 said:


> i definitely understand what the challenge is about. just thought it might be fun and it would answer a question for me. also, i never said anything about higher or lower power amps... i understand the conditions of the test. my curiosity lies behind all other things being equal, how will an unregulated amp perform next to a regulated. anyways, whatever we can let this die





kappa546 said:


> just to clarify a bit, i'm not suggesting the amps will still add a signature to the sound... i'm concerned with how well it will handle highly dynamic music which would definitely make a difference. i don't think that's outside the experiment at all


Unfortunately this will probably never die.  BTW, I may be reading more into what you wrote (in the second quote above) than what you intended so please disregard the following and my appologies if I misinterpreted :blush: . It kinda appears _to me_ that you thought I was dissing you/your idea in some way (whenever my daughter uses the term "whatever" I know I ruffled some feathers ) however that was not my intention at all and not my intention with the following...

Yes people usually just "set gains and run" however comments like "the Adcom and LP would walk all over the JL" are why I believe a lot of people don't "totally" understand the objective of "the" challenge and what is necessary to determine that objective. Although what you are "concerned with" is not "outside the experiment", it cannot be part of the "actual amp challenge" since as you know that challenge is designed to disprove that "SQ" in amps is determined by "sonic signatures" . I'll agree that most definately certain amps will "make a difference" when playing dynamic music at higher volumes due to more headroom (power) on tap and IMO "more headroom" is definately a good reason to buy one amp over another however in a true scientific test designed to prove (disprove) what this one is trying to, that "variable" _must be and is eliminated_ according to rule 3........

*3. "The test can be conducted at any volume desired; however, the amps will not be allowed to clip. In other words, listening volume can not exceed the power capacity of the smallest amp of the pair being tested. (power capacity will be defined as clipping or 2%THD 20Hz to 10kHz, whichever is less)"* 

Almost forgot, David Navone happens to have a summer home near me and he agreed to oversee a $10,000 amp challenge at last years BBQ. A vote by many of the potential attendees determined that it would just "take away" from the BBQ while probably still not settling anything "between the 2 camps" which I agreed with so we didn't have him.

Again, not trying to dis you in any way, just letting you know where I am coming from.


----------



## kappa546 (Apr 11, 2005)

sure i understand what you're saying. and imo i still don't think what i'm suggesting has breaks that rule. i guess it depends on how you interpret it. for example, take the adcom i was talking about rated at 70x2 and say it's a little underrated (perhaps even 100x2) and take a ppi art300.2. they probably put out about the same constant power but the big difference is the adcom, along with a separate chassis power supply (an extreme case but thats how this should be handled), has enough capacitance for a 1000+w amp would in fact perform better.

both amps put out equal power rms but dont have the same storage capacity for peaks. i guess that equates to more temporary power but how could you control for that? dismembering the adcom to match the ppi? in the scientific method the goal is to do everything possible to disprove the hypothesis, not the other way around. if the results fall withing a certain percentile for imporbability (usually 5%) then the hypothesis is accepted. sounds backwards but makes total sense. like i said i'm not disagreeing, but humanity is too quick to accept things just by heresay and not trying their best investigate. i'm just a curious little bee and think this is a valid proposition, if i'm wrong i dont mind standing corrected at all .


----------



## KAP (Mar 18, 2007)

If you spent 1000.00 dollars for an amp instead of say 100.00 dollars for an amp wouldnt it reason that the 1000 dollar amp would sound better to you . If it didnt you would be pissed. Right.


----------



## FoxPro5 (Feb 14, 2006)

KAP said:


> If you spent 1000.00 dollars for an amp instead of say 100.00 dollars for an amp wouldnt it reason that the 1000 dollar amp would sound better to you . If it didnt you would be pissed. Right.


_"The Law of Belief states that whatever you believe with feeling and conviction becomes your reality. It is not until you change your beliefs that you can begin to change your reality and your performance."
_
http://ezinearticles.com/?Universal-Law-Series---the-Law-of-Belief&id=70997

Another independant variable than cannot be confounded for in RC's study.


----------



## MarkZ (Dec 5, 2005)

kappa546 said:


> sure i understand what you're saying. and imo i still don't think what i'm suggesting has breaks that rule. i guess it depends on how you interpret it. for example, take the adcom i was talking about rated at 70x2 and say it's a little underrated (perhaps even 100x2) and take a ppi art300.2. they probably put out about the same constant power but the big difference is the adcom, along with a separate chassis power supply (an extreme case but thats how this should be handled), has enough capacitance for a 1000+w amp would in fact perform better.
> 
> both amps put out equal power rms but dont have the same storage capacity for peaks. i guess that equates to more temporary power but how could you control for that?


Easy. You watch both amps on a scope at the same time and make sure they don't clip at any time. If neither are clipping, then it doesn't matter if the adcom can supply a bazillion watts during peaks.

Along the same lines, a 10w amp will sound exactly the same as a 1kw amp driving a subwoofer at the same level, AS LONG AS the 10w amp never clips.


----------



## kappa546 (Apr 11, 2005)

MarkZ said:


> Easy. You watch both amps on a scope at the same time and make sure they don't clip at any time. If neither are clipping, then it doesn't matter if the adcom can supply a bazillion watts during peaks.


how would that not matter? does an amp have to go into clipping to access that reserve? does the signal determine the output as long as they don't clip? why would designers go to such lengths then needlessly?


----------



## Preacher (May 8, 2006)

The avenue to ultimate audio in the car is to modify one's transmission so the alternator receives a constant RPM and produces exactly 14.4 which will be run through an extensive power station. One amp will not sound the same as itself running at 12V 13.2V and 14.4V 


All the real audiophiles do this. All the real diy'ers machine their own gears too. Those people who claim they cannot hear the difference between 14.1 volts and 14.4V don't deserve to ride in your car and should be doomed to shop only at best-buy for the rest of their lives.


----------



## 89grand (Nov 23, 2006)

kappa546 said:


> how would that not matter? does an amp have to go into clipping to access that reserve?


Because the amps would be setup to produce the same amount of power, say a maximum of 80 watts on peaks, the extra output potential of the Adcom amp would not be revealed in the test.

I'm not saying it real world use, the Adcoms potential performance advantage would not be noticeable, but during the "amp challenge" it would not, because both amps would be setup to produce the exact same amount of power. If both amps where setup to produce 10 watts with a sinewave, then even with music, the extra headroom of the Adcom would not come into play, it wouldn't produce more power than the PPI even if it has the ability to do so.


----------



## MarkZ (Dec 5, 2005)

kappa546 said:


> how would that not matter? does an amp have to go into clipping to access that reserve? does the signal determine the output as long as they don't clip? why would designers go to such lengths then needlessly?


Because power is where it's at. So it's certainly not "needless" to try to maximize the power output of the amplifier you're designing. That's why we say that power most certaintly matters when selecting an amplifier. Not spec sheet power rattings, but real power -- a completely measurable quantity, by the way.

You can have the most reserve power in the world, but it wouldn't matter one iota if you never actually needed to use it. If a crappy amp is only capable of delivering 50 watts, for example, and the power supply sagged to the point where it could only deliver 25 watts during extended passages, then that sag wouldn't matter at all as long as you never tried to pull more than 25 watts from it. 

When we say an amplifier is 50 watts (or 25 watts, in the case of ol' saggy), then that only describes the limitations of the amplifier. The output is going to depend on the input signal, and if that input signal isn't driving the amp to its limitations, then it doesn't matter what that limitation is. You're either clipping or you're not. A 1000 watt amp isn't going to drive a speaker any better than a 10 watt amp if you're only delivering 5 watts to the speaker!


----------



## MarkZ (Dec 5, 2005)

89grand said:


> Because the amps would be setup to produce the same amount of power, say a maximum of 80 watts on peaks, the extra output potential of the Adcom amp would not be revealed in the test.


Exactly. You said it better than I did. Obviously the adcom would be the better amp when you need that extra power. 

Word of caution though: if that's solely how you judge amplifier quality, then a 1000 watt Kraco would be a better amp than a 25w adcom. Because that adcom, even with its supposedly great output capabilities during transients, still can't manage 1000 watts no matter how many capacitors you put in it. So yeah, although power output is important, reliability, aesthetics, etc also come into play.


----------



## kappa546 (Apr 11, 2005)

"80 watts *peak* wouldn't be the same as power with sines, tho sines would be significantly more than normal music. if the test tries to level match so closely (.05db) the small difference bw peak and sine (which is how im assuming they match) should be noticeable. someone correct me if i'm wrong about the above statement... i'd still like to prove this specifically either way tho like a good scientist should


----------



## 89grand (Nov 23, 2006)

If you level matched two amplifiers using a sine wave, then played music, both amps would produce exactly the same amount of power. Amps with more power or headroom do not put out more unless asked to do so, they don't just do it because they can.

If the Adcom amp has more power output than the PPI, you'd only notice it once you drove the PPI amp to it's limit, you'd then see that the Adcom was able to play louder, but if they are both running below clipping and at the same power level, there would be no difference.


----------



## kappa546 (Apr 11, 2005)

MarkZ said:


> Because power is where it's at. So it's certainly not "needless" to try to maximize the power output of the amplifier you're designing. That's why we say that power most certaintly matters when selecting an amplifier. Not spec sheet power rattings, but real power -- a completely measurable quantity, by the way.
> 
> You can have the most reserve power in the world, but it wouldn't matter one iota if you never actually needed to use it. If a crappy amp is only capable of delivering 50 watts, for example, and the power supply sagged to the point where it could only deliver 25 watts during extended passages, then that sag wouldn't matter at all as long as you never tried to pull more than 25 watts from it.
> 
> When we say an amplifier is 50 watts (or 25 watts, in the case of ol' saggy), then that only describes the limitations of the amplifier. The output is going to depend on the input signal, and if that input signal isn't driving the amp to its limitations, then it doesn't matter what that limitation is. You're either clipping or you're not. A 1000 watt amp isn't going to drive a speaker any better than a 10 watt amp if you're only delivering 5 watts to the speaker!


i understand. i think you're assuming i dont understand that the amps are level matched. i'm not stupid as to beleive manufacturer power ratings. like i said, i'm still going word for word with the challenge. am i wrong to say that even when amps are level matched to put out 25w rms regardless of their actual measured rating, which lets say is actually 100wrms/200wpeak for one and 100wrms/3000wpeak bc of extra storage, and neither is driven into clipping... during dynamic passages the you wouldnt see a single watt more? i'm being very specific about the scenario and expect the answer to be treated as such

imo people just continue to respond according to theory but dont know if this specifically has been accounted for.


----------



## legend94 (Mar 15, 2006)

:dead horse:


----------



## 89grand (Nov 23, 2006)

Correct, if the amps are level matched to produce 25 watts max, then yeah, neither amp would produce more power, regardless of what it may be capable of.


----------



## kappa546 (Apr 11, 2005)

89grand said:


> Correct, if the amps are level matched to produce 25 watts max, then yeah, neither amp would produce more power, regardless of what it may be capable of.


i said rms.

how do you set up an amp to produce max ratings? sine does not equal max.

sorry guys if i'm dragging this on needlessly, it could be the vicodin talking. i just haven't seen my specific question addressed. remember this question stemmed from regulated vs non regulated ps.


----------



## 89grand (Nov 23, 2006)

kappa546 said:


> i said rms.
> 
> how do you set up an amp to produce max ratings? sine does not equal max.


Well, you have to level match them somehow. So it you level matched them using a sine wave so that both amps were producing 50 watts with the sine wave, then after that, you played music without adjusting anything, they would produce the exact same amount of power.


----------



## kappa546 (Apr 11, 2005)

89grand said:


> Well, you have to level match them somehow. So it you level matched them using a sine wave so that both amps were producing 50 watts with the sine wave, then after that, you played music without adjusting anything, they would produce the exact same amount of power.


thats what i dont beleive... not questioning what they're putting our rms bc they're level matched, but anything above rms during highly dynamic music (remember there can be as much as 30db peaks in some cases) is what i think would be a different story. anyways, this is gettin nowhere... i'm through


----------



## 89grand (Nov 23, 2006)

kappa546 said:


> thats what i dont beleive... not questioning what they're putting our rms bc they're level matched, but anything above rms during highly dynamic music (remember there can be as much as 30db peaks in some cases) is what i think would be a different story. anyways, this is gettin nowhere... i'm through


Well it might as well be done, because you refuse to accept the facts for some reason.

What you're talking about right now, has nothing to do with the "amp challenge". It's not the point here. No one ever said a more powerful amp will not produce more power than a smaller amp if pushed hard enough, but if they are setup the same and level matched within the power limitations of the smaller amp, then they would produce the same amount of power and you wouldn't be able to tell the difference between them and ....that's really all there is to it.

If two identical cars where driving down the freeway at 75mph, it wouldn't matter if one had a blower and had 150 more horspower than the other as long as they where both going 75mph. Sure the car with the blower could go faster than the other, but if they where both going 75mph, the car with the blower has no advantage.


----------



## GeoffB (Feb 3, 2007)

There is a post on www.talkaudio.co.uk in the FAQ section with all the amp challenge rules but it also includes all of RCs coments in threads about the challenge from carsound forums over the years (with other posters coments edited out)
The thread use to be at http://www.talkaudio.co.uk/vbb/showthread.php?t=18815 it may have moved but it will still be in the FAQ section with the thread title 'Amp challenge rules, revisions & posts'.

Its funny but i was only resent going through old posts of RCs on carsound rereading how the rules originated and he was also appling/adapting them to CD players due to how they originated, and also how David Clark from home audio was the originator of the rules and i think from the title of David L. Clark/Ian G. Masters magazine article "Do all amplifiers sound the same?" is why the RC rules get the reply the comon misunderstood lines of 'all amps sound the same' 'a watt is a watt' etc.


----------



## kappa546 (Apr 11, 2005)

89grand said:


> Well it might as well be done, because you refuse to accept the facts for some reason.


thats if i assume, like you do, that they are in fact level matched for max power and not rms. if thats somehow the case then yea im done... can't argue with that. so to the EE's out there, is the "power limits of the smaller amp" inclusive of _measured max ratings_? how ironic would it be that in this strictly objective test "max power" isn't absurd.

now lets assume i am wrong and max power is accounted for somehow. can anyone explain how that's done? because while two amps can _continuously_ put out the same _measured_ amount, their reserve power can greatly differ. conversely if you're level matching their max output how could rms be the same? jeff, chad?

btw i hope you guys understand i'm not contradicting the test and it's purpose/meaning.


----------



## fej (Feb 8, 2006)

Going over/under 14 pages on this topic before it dies .. only to be revived next year  

I still think you pay for advertised watts .. if you buy a $80 100x4 amp you are likely to get 40x4 useable watts (before clipping). If you spent $300 on the same amp you are far more likely to get useable "advertised" watts, often times exceeding the output when tested at 14.4v. Everything else is just chassis, aesthetic, and features that are built in.


----------



## MarkZ (Dec 5, 2005)

kappa546 said:


> i understand. i think you're assuming i dont understand that the amps are level matched. i'm not stupid as to beleive manufacturer power ratings. like i said, i'm still going word for word with the challenge. am i wrong to say that even when amps are level matched to put out 25w rms regardless of their actual measured rating, which lets say is actually 100wrms/200wpeak for one and 100wrms/3000wpeak bc of extra storage, and neither is driven into clipping... during dynamic passages the you wouldnt see a single watt more? i'm being very specific about the scenario and expect the answer to be treated as such
> 
> imo people just continue to respond according to theory but dont know if this specifically has been accounted for.


I think a lot of the confusion in the questions you're asking and in the answers you're receiving has to do with the idea of power. Amplifiers are best thought of as voltage devices. That is, give it a signal of X volts and you'll get A*X volts out (where A = the gain of the amplifier -- not to be confused with the gain adjustment knob that may or may not be present in the amp). But the amp is only capable of a certain amount of output voltage, which is dictated by its power supply. In theory, this maximum voltage is constant. Any attempts to exceed this voltage will result in clipping. In practice, however, this maximum voltage will usually decrease a little depending on how hard you're pushing it. This is mostly due to losses in the power supply. But regardless, there is a maximum voltage and you can use measurement equipment to see whether or not the output signal approaches this value and is clipped.

If a signal that's designed to really test the dynamics of an amplifier is applied, it'll be reproduced faithfully by any amp assuming the following:
1) no portion of the dynamic signal exceeds the max voltage (where clipping would occur)
2) the dynamic signal isn't so fast that the amplifier can't keep up (slew rate limitations -- never an issue in modern day solid state amplifiers)
3) the signal isn't distorted or attenuated in frequency or shifted in phase due to the distortion properties and frequency response properties of the amplifier.

So the answer is: no, there won't be any difference between the crappy 10 watt amp and the expensive 1000 watt amp, as long as no portion of that dynamic signal exceeds the maximum voltage output of the 10 watt amp. In other words, as long as clipping doesn't occur.

You bring up the "30db" number to refer to dynamics. But it's a relative number. You probably mean a signal where the peaks exceed the lulls by 30dB. Well, the 10 watt amp will do a great job with it, as long as those peaks don't exceed the maximum voltage that the amp can provide. Again, it's an issue of clipping.

A couple more things if anyone out there is still reading. If two amplifiers are truly level matched, as you said, then any signal that you apply to their inputs will be of the same magnitude on the output. Remember the equation above output = A*input. That applies to any signal you give the amp. Multiply the input signal by A (the gain) and that's the output. So whether you level match with sine waves, noise, or whatever -- as long as you level match with one signal, they'll stay level matched with any other signal. Again, unless you clip.

One more key point that I think you may be overlooking. The maximum power output between two level-matched amplifiers can be very different. The adcom amp may have reserve power that's really great and the kraco may not. All that does is determine at what point the amplifier will clip (and maybe what it will sound like when it does clip). But if you level match them then none of that matters. That's because _the gain never changes_. Yes, maximum output can change -- reserve power, power supply losses, etc. But the gain is always constant until you change that little knob.

Here's an example. Suppose your amp is rated for 100w at a battery voltage of 12.5v but 120w at 14.4v. Suppose you're playing a 20w sine wave while the battery voltage is at 12.5v. You turn your car on and the battery voltage jumps up to 14.4v. Will the sound get louder? -- the answer is NO. The gain does not change. Only the maximum voltage output before clipping changed. But you weren't clipping, so the output of the amp remained exactly the same.


----------



## kappa546 (Apr 11, 2005)

that's exactly the answer i was looking for. reserve power is accounted for in ps output voltage. this actually makes me appreciate my LP's much more now

so if the reserve power determines at what point the amp will clip, then one could have an amp with much higher measured power output but less capacitance to match the adcom in real world use. ie get a pyramid 200wx2 rms to match the adcoms 70x2 with dynamic passages (assuming their max output voltage is equal). so i'm basically restating the test lol


----------



## MarkZ (Dec 5, 2005)

kappa546 said:


> that's exactly the answer i was looking for. reserve power is accounted for in ps output voltage. this actually makes me appreciate my LP's much more now
> 
> so if the reserve power determines at what point the amp will clip, then one could have an amp with much higher measured power output but less capacitance to match the adcom in real world use. ie get a pyramid 200wx2 rms to match the adcoms 70x2 with dynamic passages (assuming their max output voltage is equal). so i'm basically restating the test lol


It's more than just capacitance that determines how the power supply will hold up during transients. You've got losses all over the place -- sometimes reserve power simply means a lack of losses. So if you use components that are oversized for the job and you're able to cut your losses down, then the PS will be less likely to sag during peak demands. That, in a sense, is reserve power.

Some of it is also how the supply is regulated. PWM supplies dynamically alter their current consumption based on how much current needs to be delivered. From what I understand there can be different strategies used to drive the PWM controllers, but I don't know enough about that to elaborate.


----------



## kappa546 (Apr 11, 2005)

excellent. when i get a chance i'll pm you some details on the ps and output devices in one of my 2.2's to see what you think. i know they're a tad overbuilt


----------



## Mr Marv (Aug 19, 2005)

kappa546 said:


> that's exactly the answer i was looking for. reserve power is accounted for in ps output voltage. this actually makes me appreciate my LP's much more now
> 
> so if the reserve power determines at what point the amp will clip, then one could have an amp with much higher measured power output but less capacitance to match the adcom in real world use. ie get a pyramid 200wx2 rms to match the adcoms 70x2 with dynamic passages (assuming their max output voltage is equal). so i'm basically restating the test lol





Mr Marv said:


> Also, if you do a "true scientific test" it won't matter if it's regulated or unregulated since _all other variables must be removed_ (ie: each amp must play at the same level within the unclipped limits of the "lesser power" amp").


I guess I didn't use enough words when I answered that question several pages ago   . Glad it makes sense to you now  and let me know if you are coming to the BBQ. BTW, we don't discuss religion, politics or _the amp challenge_ during the BBQ


----------



## 60ndown (Feb 8, 2007)

MarkZ said:


> So the answer is: no, there won't be any difference between the crappy 10 watt amp and the expensive 1000 watt amp.


wes my $10,000?


----------

