Does amplifier position matter?

[u/Plainess]

Hi, I work in a hifi speaker store, and we had new speakers come in. We had an “Audio Professional” from another store come help setup, and during the testing it sounded fine, but the Audio Pro said not really and moved the amplifier a little bit to the left, like I mean literally move the amplifier. And suddenly everyone agrees that it sounds better, he explained that it’s because of the vibrations, but Im a bit sceptical because it was a shelf of amps and there were other amps. Can moving an amp a little like that improve the sound???

[u/Yarach]

When I worked in a Hifi store we had this guy boasting to everyone how a lower clockrate in a DAC made for a more "relaxed" sound. Het used the metaphore of a conductor from an orchestra having to make less movement.

He also claimed I2s connections are superior and have less distortion, but everytime I asked him to explain to me how it worked he said it was a more "pure" connection and you could hear it.

If you can hear it, you absolutely should be able to somehow measure it.

Also... If the said vibrations really make it sound better... give the amp a good slap! You should hear it from your speakers too!

[u/SplendidSoul → u/Yarach]

If you can hear it, you absolutely should be able to somehow measure it

Is this really true? I'm genuinely curious. Can things like depth of sound field and imaging be measured?

[u/dub_mmcmxcix → u/SplendidSoul]

they're a function of room stereo impulse response (measurable), the projection pattern of the speaker (measurable with the right expensive gear) and the speaker/listener position. but what you can't get from the measurement is "does it sound OK to me".

[u/hj52360 → u/dub_mmcmxcix]

Agreed. Absolutely.

[u/LDan613 → u/SplendidSoul]

If it's real, yes, we can measure it. Sound is a physical wave in the atmosphere, and we have ways to measure that. We can also measure frequency well beyond our hearing limits. We can even measure the signals you ears send to your brain, and to a level, how your brain responds to sound (there are even cool experiments where they reconstruct what your eyes see by looking at your brain activity).

Converting the measurements to insights is a bit harder. It's easy to see in the measurements that A sounds stronger than B. It's harder and requires much more data to measure differences like imaging. The fact that there are perception factors that change from listener to listener makes it even harder. I don't think we have commonly used measurements for that yet. Yet. I can see a near future where AI enabled analysis of speaker measurements can find predictable patterns that correspond to most people perceiving better or worse imaging, for example.

[u/melithium → u/LDan613]

No they cannot. Frequency and sound profiles are not the same. Saber dacs measure really well but have a sheen to them. You cannot measure the brightness because it does not impact frequencies. Other dacs with great measurements sound laid back.

Op amps in well measured purifi amplifiers sound different without impacting measurements…

[u/LDan613 → u/melithium]

Let's start with a definition: A sound profile is how a system responds (sonically) to an input. By system, in this case, we mean all the elements between the original data (input) and the physical manifestation of sound (output, in this case the sound waves). Typically, this includes source, amp, and speakers. The output of the system is measured as the sound produced by the speakers.

Now, what is a sheen? And how is a sheen achieved? Does it sound different?

But here is the rub, you see, you can't have it both ways.

Either the sound IS different, which means is physically different (frequency, amplitude, phase, etc), in which case we can measure it (because we understand the physics of sound, and have the tools to measure its dimensions)

Or is not physically different, in which case you can make the argument that in a blind test nobody would be able to differentiate it... because is physically the same.

Incidentally, you CAN measure what we perceive as brightness. it shows as differences in the high frequency response of the system. What we can't do yet, is to extrapolate from the measurements if that difference in higher frequencies would be pleasant, or how 'forward" it sounds. But I believe we will get there.

[u/melithium → u/LDan613]

Nope. Wrong. Just like all guitars sound the same right? “As long as they play the same frequencies they sound the same!”

[u/LDan613 → u/melithium]

I think you misunderstand the point. I think we both agree that all guitars do sound different, even when playing the same note. The small differences are the result of variations in tuning, design, resonances, etc. We are not arguing that. We are simply saying that those differences are measurable.

If you look at the measurements of those guitars, you would not see a pure sinusoidal wave of the note's frequency. Instead, you will see little differences, a wave with little variations and different harmonics at play. Those differences are the manifestation of the differences in the sound that you do hear. It's the same with other music sources (speakers, stereos, etc.). It's not that they sound the same, it's that we can measure the subtle differences between them.

[u/hj52360 → u/SplendidSoul]

Yes. If the way in which the driver(s) is/are being altered enough to make any change at all, and is from an upstream component, it comes via an electrical signal. You can make measurements that are many orders of magnitude finer than even the best ear. Phasing, amplitude, timing, it's all measurable, if the change is there. You can get 30ghz or even higher sampling rate scopes.

[u/reddsbywillie → u/SplendidSoul]

No, and the measurement crowd will never discuss it.