Amplifiers can you hear a diffrence?

[Blumlein 88]

This is true, but there is some irony involved with the reviews of this site, as they can have a tendency to have their own biasing influence on peoples perception of equipment. I've seen people obsessing in here about small differences in performance in converters that I am certain are not distinguishable in listening tests. This is an inversion of the traditional idea behind "objective evaluation" of audio gear.

The origins of the "subjectivist vs objectivist" debate are the result of claims by subjectivists that some, usually very expensive, piece of audio gear sounds amazing and much better than the cheaper competition. Even when measurements show their is not a significant difference, the "golden ears" audiophile will claim that there are aspects of sound reproduction (the electrical versions of the signal) that cannot be measured!

I've been humbled many times in audio, so I am wary of absolutes, but I am confident that this is nonsense.

In addition to the measurements, careful AB or ABX testing has proved that "Golden Ears" cannot distinguish the gear they showered with superlatives in sighted listening. (This then leads to the argument that the kind of sonic differences they are perceiving are not well detectable in AB/ABX type testing. This is a weird claim.)

Amazingly, this argument still rages.

The traditional objectivist view is that anything perceptible in audio reproduction is measurable. A practical corollary is that once a piece of gear reaches a certain level of performance, no audible improvements can be made. This means the consumer can shop with confidence, for an amp lets say, based on criteria like: power, price, visual appearance, features, ergonomic aspects, warranty, reputation and the like, as long as the amp is from a reputable company and performance hits a certain objective point.

On ASR the speaker reviews are in a different category than the measurements of electrical performance. The research these tests are based on are grounded in subjective preference testing of speakers. Without this foundation, the measurements have little value. It is not axiomatic that accurate reproduction of sound is always the best.

This holds because speakers are easily distinguished, even in blind tests.

The reviews of other gear on ASR have no corresponding foundation in careful evaluation in listening tests.

I think most people here would agree that the audible performance of gear that measures differently is often not perceivable in listening tests.

This puts the drive for the "best performing" amp into a weird category. It reminds me of the drive to own a fast sports car, even though the driver never has the opportunity to test the limits.

I find this to be strange, but I appreciate the impulse to find the absolute best performance.

One thing it does allow the listener is, at the least, rule out that particular piece of equipment if they are unsatisfied with the sound they are experiencing with their system.

A fascinating test would be to see at what point on the ASR master DAC list an audible difference could be detected in a reasonably well done listening test. Presumably some of the worst performing converters would be noticeable, but my guess is that it would get pretty hard even down in the 3rd section of "mediocre" devices, like the phone dongles.

I agree with much you say here. I've posted 8th generation loopback copies of music and let people hear it. The most recent one I can ABX them. So could some others. Why? Because the ADC I used had a slightly rippled frequency response. Not enough to hear in one pass thru, but after 8 of them enough to be discernible on some music. I've done the same a few years earlier. In that case I was lucky in my DAC has a very slight up tilt for upper frequencies and the ADC a slight down tilt. They by happenstance compensated perfectly, and after 8 generations response was 0.0 db at 20 khz. People couldn't hear those as different.

The SINAD for the gear in the latter case was somewhere in the upper 90 db range. After 8 generations it was in the lower 80 db range. So could we be just fine with DACs having 85 db and above for SINAD if FR is flat? I think probably so if noise is low enough you don't hear it. Yet I've seen people pondering over a couple db SINAD for devices that already were lower than -115 db. That isn't fully rational either though I understand if you can get more than you need at no or very little extra cost then sure get the better measuring gear.

Earlier in this thread I've said I found a Spectral to be transparent. It had pretty low noise, and wide bandwidth, but THD was in the mid -70 db range at full power.

I've said before I think you have some margin of safety if you have THD of -70 db, IMD of -80 db and noise low enough not to hear which will vary from -90 to -100 db depending upon speakers and room and flat frequency response to 20 khz. Perhaps with test signals and particular conditions this isn't good enough to be transparent, but it will be for 99% of possible cases and likely 100% of music.

 

[b1daly]

Quite. Objective extremism is no more helpful than subjective extremism.

Re speaker tests, isn't it interesting that whilst our current view on "what's best" (Toole) is based on subjective evaluation, it still correlates with intuitively technically good performance. Ie smoothest flattest anechoic response with smooth off axis response.

It is interesting, but intuitively this result was not what I expected. My instinct was that listeners would prefer slight boost in the bass and treble ("smile" curve") based on anecdotal observations on how people set their playback systems, and the ubiquity of things like "turbo bass" settings on various playback devices.

One explanation for this is generally people impart EQ shapes to their playback systems by boosting frequencies (i.e. turning up bass or treble.) This makes the overall signal louder, which on immediate comparison sounds "better". If one was to impart a "smile" curve with a graphic EQ by instead subtracting frequencies in the middle, I would expect far fewer listeners to hear this as an "improvement" as the EQ was toggled in and out of the circuit.

Recorded audio presents some paradoxes compared to live music, because levels are "relative" not "absolute." On a practical level, a broad boost in a high shelf EQ is equivalent to a cut in the frequencies below the corner frequency.

The other reason this result is so surprising is that the listeners in the test have no knowledge of the original tracks. Given that extensive processing is used in pop recording, and the relative lack of flat monitoring systems in recording studios, a preference towards an "accurate" playback system is not obviously expected. My intuition about this is that skilled music producers (defined broadly) target a broad range of playback systems, and the average of these playback systems presents a conceptual average towards a neutral playback system. There are also skills that allow the mixer to transcend the limitations of the production monitoring systems. (This is how the "circle of confusion" is escaped.)

This is not universal in pop music. Some rap music is intended to be played back on systems with exaggerated sub frequencies, and the full experience is not rendered on a flat playback system.

 

[March Audio]

It is interesting, but intuitively this result was not what I expected. My instinct was that listeners would prefer slight boost in the bass and treble ("smile" curve") based on anecdotal observations on how people set their playback systems, and the ubiquity of things like "turbo bass" settings on various playback devices.

One explanation for this is generally people impart EQ shapes to their playback systems by boosting frequencies (i.e. turning up bass or treble.) This makes the overall signal louder, which on immediate comparison sounds "better". If one was to impart a "smile" curve with a graphic EQ by instead subtracting frequencies in the middle, I would expect far fewer listeners to hear this as an "improvement" as the EQ was toggled in and out of the circuit.

Recorded audio presents some paradoxes compared to live music, because levels are "relative" not "absolute." On a practical level, a broad boost in a high shelf EQ is equivalent to a cut in the frequencies below the corner frequency.

The other reason this result is so surprising is that the listeners in the test have no knowledge of the original tracks. Given that extensive processing is used in pop recording, and the relative lack of flat monitoring systems in recording studios, a preference towards an "accurate" playback system is not obviously expected. My intuition about this is that skilled music producers (defined broadly) target a broad range of playback systems, and the average of these playback systems presents a conceptual average towards a neutral playback system. There are also skills that allow the mixer to transcend the limitations of the production monitoring systems. (This is how the "circle of confusion" is escaped.)

This is not universal in pop music. Some rap music is intended to be played back on systems with exaggerated sub frequencies, and the full experience is not rendered on a flat playback system.

Remember that flat "anechoic" response does not equal a flat in room response. You will get a low frequency lift and high frequency drop.

Have a look at some of Amirs speaker measurements and you will see this. One of the plots is an estimated in room response.

 

[Pjetrof]

To all, thx for time to reply.
after more than 2 years reading different forums starting threads etc etc. People should filter the internet, cause lots of
BS!
What I can say very humble not an engineer, just a music lover who found sanity!
i will duplicate what I wrote on the harbeth forum.
i did this test after all the replies and recommendations everyone did.
everyone is a free (most of us) indivendual and does how it please him.
concerning amplifiers this is how my stand is

“Hi all,
aport from how they look and feel etc for sure the Accuphase in my eyes is complete different league then the Behringer.
Price is multiple 10! But the sound isn’t.
But ......."
“But ....... when people describe wine sometimes they use the term fuller! This wine taste fuller!
the glasses are the same amount, but everyone accept the term fuller.
Why do I say this, well that diffrence I hear If I play loud not so loud Very loud doesn’t matter the diffrence stays.
not worse sounding not better but can’t explain .... by more modern music for example “dance monkey from tones and I“ the Behringer does this kind of music better than the Accuphase for my ears but “Danny Vera Rollercoaster“ the Accuphase is for my ears better and I ve been testing this for days now only those two songs in my system in my room with different loudness volume. That is what my ears hear. Would if I didn’t had the Accuphase buy one now? Not in 2 million years, even if I win national lottery! I know realibility etc etc I can buy 10 behringer for 1 Accuphase so every 2 year a new one or 1 Accuphase for 20 years. Plus accuphase 30 watt Behringer 200 watt so ........ fill in dots for yourself I know mine answer!
So again to come to the other choice quad artera any other amp Hegel Yamaha Etc same answer Why???
Behringer 179 euro I paid! IT DOES THE JOB! It amplify!

 

[Pjetrof]

Want to restart this thread after reading well respected Mr. John Siau in the thread benchmark AHB2 amp.
He states amplifiers sound different.
If so then is this radical different then how this forum thinks.

 

[Pjetrof]

If amplifiers sound different depending which speaker load, well then it becoming a long task to find the sound you like!

 

[RichB]

If amplifiers sound different depending which speaker load, well then it becoming a long task to find the sound you like!

The smallest, coolest amp that is reactive load invariant. One that, not only remains stable, but does not increase distortion. Preferably, without producing gobs of out of band noise as well. There should be status indicators when clipping, alerting the user, and with excellent protection circuitry

I have done voltage-level match comparisons of the AT4002 and AT522NC driving Revel M20 bookshelf speakers and was able to distinguish them. I preferred the AT4002 but I am quite sure that many would prefer the AT522NC.I sent my AT522NC to ASR and it measured well.

- Rich

 

[sergeauckland]

If amplifiers sound different depending which speaker load, well then it becoming a long task to find the sound you like!

If amplifiers sound different depending which speaker load then the amplifier is not suitable for the job. It's possible the load is unreasonable, and few loudspeaker manufacturers ever keep to the IEC recommendation for rating impedance, but with that caveat, if an amplifier can't drive one's chosen load, it's the wrong amplifier and should be replaced by something more capable. Finding a sound you like is not, in my opinion, the way to do it. Find an amplifier that works, then enjoy the sound you get.

S.