ryls

iTrader: (1)

also regarding amps, the noticable differnce to me is in "clean power", and in car audio if you like it loud you need decent amps to supply that power cleanly. To me dukk the biggest flaw in your test that you mentioned in the other thread is how deck power sounded as good as some fancy *** amp, and sure at those low levels of power in a listening room enviroment im sure they sounded quite simillar but how would that deck sound in a car drivng threw town? You just need more power than that in a car enviroment IMO. Once you start demanding more power distortion rates can skyrocket on some amps they go up a fair bit on plenty good amps to if you measure distortion to the point of someone like zuki lol

JohnVroom

I agree the ABX test is an issue, I think the act of ABX tends to favor volume, but when volume is matched, the test that is left to the listener is to audibly measure the sum of errors, I think this is particularly difficult with car audio as it has a lot of deficiencies even in the finest equipment (a automotive HU is too small for the guts of most home AM/FM tuners to fit in). Having said that, the RC challenge could effectively have used home audio or studio equipment and I think the results would be the same. For the test I took, which was different than many RC did, we used a computer to match level, the computer also EQed the signals so they were +/- 1dB. I could hear a difference and select it (on the portions I was certain of which amp was which I was 100% correct ... but that was only 40% of the time) then there were portions I could not tell which was which and my score showed it. So statistically RC said "you were guessing" but I dont think that was correct either. Frankly the difference in amps or wires is subtle at best. RC confided that with the very best ears he had to EQ down to 1/4 dB till the folks who actually have 'golden ears' couldnt win the $$. That does not lessen the importance of the test, though in all fairness it is not a scientific test but it is as good as you can do with an ABX.

Why is it when you live with a component (lets say an amp or pre-amp) for a while you hear defects in its sound but when you ABX you dont? which is correct? How can the sky be blue one day and green the next? How can my wife come in the room and tell me the same thing I am hearing when I swap amps or cables when she REALLY doesnt care about audio hardware or have a clue if I have done anything to my system at all (and switching out one component with matched volume IS technically a scientific test).

So yes there is an audible non-truth going on here, the question here is it a mechanical (ear based), a psyco-acoustical issue, or is it placebo/ wishful thinking. I think there is a viable argument for any of the three.

kevmurray

Hi Zoomer, I think we're pretty much in agreement except for:What do you mean by the impedance causing problems at lower frequency? I assume you mean the below 4 ohm range common in car audio. If so then I suppose a poorly designed amp (cheap) might be noticable, but all amps exhibit much higher distortion at higher frequencies. We rarely see distortion figures published for other than 1kHz. Certainly not higher. Also lower frequency distortion is far less audible to humans. I just know I wouldn't be able to tell two apart in an ABX test (level matched). Providing one is not total garbage of course.

kevmurray

John, how was the EQ performed in the ABX test? Isn't that cheating anyway since an amp should be flat? Who hosted the test? (and whats "RC"? )

zoomer

iTrader: (3)

no, not simply 4 ohm or lower speakers. I ment for amps in general. At lower frequencies woofers exhibit very low impedance characteristics that may be difficult for amps to handle. Thus differences in "punch" "tightness" and "control" but I think we are getting into much more than what the original poster intended.

And I never understand anything Mr Vroom says.

JohnVroom

A computer based audio software program (did not catch the software title) to level the amps performance electrically as manufacturers plot EQ into their designs to produce their 'house sound'.
is it cheating? Well yes and no, the ENTIRE point of Richard Clark's (RC) amp challenge was NOT to prove all amps sound the same but to prove there wasnt any inherent magic in one properly designed amp over another. It isnt cheating if you think an amp has a specific sonic signature, no one has been able to conclusively prove that even without EQ. If I can discern a loudness difference between amps then I could ID the louder amp every time. I have decent hearing, no golden ears here, but I can still hear 20-20k and I have reasonable pitch recollection, and have enough experience with musical instruments to detect correct timbre.
if you think all amps sound the same then it was cheating... (or pointless)

JohnVroom

well I try to be literate.. and I did learn to speak the Queens English in Montreal

kevmurray

Ah ok makes sense then. I wouldn't call them a proper amp then but I suppose there is no real definition indicating that an amp is the proverbial "straight wire with gain".
This I completely agree with. RC and I would get along famously. I've designed and built several amps of different topologies from scratch, and I firmly believe you should not "hear" one. OK some would not have passed the test but they were scrapped for that reason.
I think amps should not sound like anything. If they do (Mr. Bose) then I have a problem with it. I'd say any designed-in curve or distortion characteristic makes it a processor with gain. This is where the discussion degrades as it's only my opinion.
All amps do not sound the same. All proper ones don't sound like anything.

zoomer

iTrader: (3)

John, You may recall the famous Bob Carver amp challenge. For stereophile magazine he made is $600 magnetic field amp sound the same as a $5000 conrad johnson amp. He did this i 48hrs in a hotel room by adding analog circuitry to make the 2 amps have the same transfer function. In fact after 24 hours his amp had better bass reproduction so he muddied up the bass.

This does show that amps do sound different. It is not some esoteric design difference but simple differences in transfer function that could be dialed in at will.

AAAAAAA

iTrader: (7)

It does not show they sound different.... for that they would of had to have a proper abx test to first be able to determine\prove that they CAN tell a difference when they aren't looking at the device.