What new measurement can we develop to explain the difference in what we heard

[MasterApex]

I have read many amp reviews that show measurement for:
1) THD + Noise with sinewave
2) Intermodulation distortion with sinewave
3) SNR with sinewave
4) Frequency response with dummy load 84/2 ohm

While they are useful I often wonder if there are other measurement that can be developed to explain what we heard.

For example when comparing two amps with similar measurement quality per but sounds very different on a full range speaker say a B&W 802D3.

Very often we observe :
1) The tonal balance does not sound the same - more weight (almost like connecting same speaker speaker with 24AWG wires vs 10AWG cables), brightness difference (almost like there was treble settings)
2) Different comfort level for loudness (measured by SPL) . When playing life classical recording like 1821 overture (wide swing dynamic from 40dB to 90dB sound) , our ears are more comfortable playing louder with Amp A vs Amp B even though their 1-4 measurement does not clearly explain it (similar frequency response, etc) but our SPL meter shows that we are more willing to crack the volume up higher. Perceived distortion ? In movie theater , the sound is so loud that we can't carry conversation but our ears are ok with it.

So as music is complex waveform and not a sinewave,
I wonder if there is/are additional measurement that can explain differences what we heard in audio amplifier sound quality that is not explained by 1-4 above via sinewave signal inputs.

 

[Koloth]

Man, i have some amazing news for you: you're about to make a buckload of mine since you'll certainly be able and willing to prove your ability to distinguish those different gauge wires in a blind abx listening test!
You'll be rich and famous!

 

[SIY]

I have read many amp reviews that show measurement for:
1) THD + Noise with sinewave
2) Intermodulation distortion with sinewave
3) SNR with sinewave
4) Frequency response with dummy load 84/2 ohm

While they are useful I often wonder if there are other measurement that can be developed to explain what we heard.

For example when comparing two amps with similar measurement quality per but sounds very different on a full range speaker say a B&W 802D3.

Very often we observe :
1) The tonal balance does not sound the same - more weight (almost like connecting same speaker speaker with 24AWG wires vs 10AWG cables), brightness difference (almost like there was treble settings)
2) Different comfort level for loudness (measured by SPL) . When playing life classical recording like 1821 overture (wide swing dynamic from 40dB to 90dB sound) , our ears are more comfortable playing louder with Amp A vs Amp B even though their 1-4 measurement does not clearly explain it (similar frequency response, etc) but our SPL meter shows that we are more willing to crack the volume up higher. Perceived distortion ? In movie theater , the sound is so loud that we can't carry conversation but our ears are ok with it.

So as music is complex waveform and not a sinewave,
I wonder if there is/are additional measurement that can explain differences what we heard in audio amplifier sound quality that is not explained by 1-4 above via sinewave signal inputs.

Why do you restrict things to "sine wave"? And then contradict yourself with IMD? Do you have any basic understanding of audio measurements?

And please provide ONE example of a demonstrated audible difference between two pieces of electronics that is not easily measurable. One.

 

[BDWoody]

For example when comparing two amps with similar measurement quality per but sounds very different on a full range speaker say a B&W 802D3.

Have there been any properly controlled tests supporting this? There are many supporting anecdotes, but that's not really useful to track down what to measure.

If someone can distinguish between them under properly controlled conditions, that would be a good place to start.

If they can't, then the difference wasn't in the gear.

Still waiting on anyone, anywhere to demonstrate what you seem to be claiming.

 

[MZKM]

For example when comparing two amps with similar measurement quality per but sounds very different on a full range speaker say a B&W 802D3.

Well, not too many people know about phase, and being able to calculate EPDR is something even less people know about.

2 amps could have identical measured wattage into 4 ohm, but load it on a real speaker and both amps will differ in bass performance. I don’t know if it would damage some amps, but we really should be measuring 2ohm performance (I think last time I said this Amir responded in agreement but he’d need a new dummy load).

 

[Pennyless Audiophile]

Please do not gang on like this on people asking these questions, the fact that human hearing is easily fooled doesn't mean it is always fooled.
Furthermore, not everyone is expected to have the technical knowledge to understand what we are talking about.

I believe this site is lacking a "start here" section where users asking question like this could be forwarded. I am probably not knowledgeable enough to write it, but if there is anyone wanting to do it, I would be happy to support him/her as much as I could.

 

[tomtoo]

What we can measure is much more than we can heare. So the question is more, whats the importend data?

 

[Hayabusa]

4) Frequency response with dummy load 84/2 ohm

Simular measuring amps could measure quite different when connected to a real load , like the B&W speaker you mentioned.

 

[Frgirard]

https://www.audiosciencereview.com/forum/index.php?threads/measurements-what-we-hear.23610/

 

[dfuller]

Frequency and/or power response into an inductive load is probably the big difference here. Some amplifiers will have a more-than-negligible difference between an inductive and resistive load.
I would like to see a dummy load that simulates a 2-way ported speaker as part of testing.

 

[SIY]

Some amplifiers will have a more-than-negligible difference between an inductive and resistive load.

Example?

 

[phoenixdogfan]

Well, not too many people know about phase, and being able to calculate EPDR is something even less people know about.

2 amps could have identical measured wattage into 4 ohm, but load it on a real speaker and both amps will differ in bass performance. I don’t know if it would damage some amps, but we really should be measuring 2ohm performance (I think last time I said this Amir responded in agreement but he’d need a new dummy load).

The way to measure something like that is with a thing calles the "power cube" which places output in volts, phase angle and rersistance in ohms on three separate axes. Ideally what would be seen is a cube which would mean an amps output was invariant no matter the resistance and phase angle to the load . The late Peter Aczel used to measure amplifiers in that way and he, along with a German audio magazine were the only reviewers who to my knowledge used it. I understand it requires an expensive piece of gear to pull off, but I think it's worthwhile because it provides a way of asessing the quality of an amp's power supply.

 

[SIY]

The way to measure something like that is with a thing calles the "power cube" which places output in volts, phase angle and rersistance in ohms on three separate axes. Ideally what would be seen is a cube which would mean an amps output was invariant no matter the resistance and phase angle to the load . The late Peter Aczel used to measure amplifiers in that way and he, along with a German audio magazine were the only reviewers who to my knowledge used it. I understand it requires an expensive piece of gear to pull off, but I think it's worthwhile because it provides a way of asessing the quality of an amp's power supply.

I am absolutely lusting after a Power Cube. I have been unable to talk them into donating one to me.

 

[JeffS7444]

I have read many amp reviews that show measurement for:
1) THD + Noise with sinewave
2) Intermodulation distortion with sinewave
3) SNR with sinewave
4) Frequency response with dummy load 84/2 ohm

While they are useful I often wonder if there are other measurement that can be developed to explain what we heard.

For example when comparing two amps with similar measurement quality per but sounds very different on a full range speaker say a B&W 802D3.

Very often we observe :
1) The tonal balance does not sound the same - more weight (almost like connecting same speaker speaker with 24AWG wires vs 10AWG cables), brightness difference (almost like there was treble settings)
2) Different comfort level for loudness (measured by SPL) . When playing life classical recording like 1821 overture (wide swing dynamic from 40dB to 90dB sound) , our ears are more comfortable playing louder with Amp A vs Amp B even though their 1-4 measurement does not clearly explain it (similar frequency response, etc) but our SPL meter shows that we are more willing to crack the volume up higher. Perceived distortion ? In movie theater , the sound is so loud that we can't carry conversation but our ears are ok with it.

So as music is complex waveform and not a sinewave,
I wonder if there is/are additional measurement that can explain differences what we heard in audio amplifier sound quality that is not explained by 1-4 above via sinewave signal inputs.

Make sure that you precisely match levels when comparing electronics, like +/- 0.1 dB or better. Otherwise, the louder one will tend to sound more "exciting".

As for sine waves, actually, complex signals including square waves are made up of sine waves, though they're composites of multiple frequencies. As such, there's really no such thing as a "pure" 1 kHz square wave, it's actually a fundamental tone and a bunch of harmonics.

 

[Gorgonzola]

First we must address the issue of whether there ARE audible difference among essentially sound electronic components. There are major segment of folks, especially here at ASR, who question whether people can hear difference as opposed to simply imagining them.

I'm not an engineer or any sort of scientist, so I can only speculate. I often hear difference and I am reasonably convince they are often real. But I'm inclined to believe that the difference correlated with measurements that are usually made by Amir, et al.

For example, I suspect harmonic distortion spectra correlate with sonic qualities often described as warmth, musicality, and layered imaging. I notice a tendency in some quarters to simply deny the audibility of whatever may be causing these perceived qualities rather than scientifically explore what is causing them.

 

[SIY]

For example, I suspect harmonic distortion spectra correlate with sonic qualities often described as warmth, musicality, and layered imaging. I notice a tendency in some quarters to simply deny the audibility of whatever may be causing these perceived qualities rather than scientifically explore what is causing them.

You answered that in the beginning- the first step is to verify that the differences are actually audible. When that's a positive, the measurements are extremely easy and straightforward, not much to "explore."

 

[BDWoody]

First we must address the issue of whether there ARE audible difference among essentially sound electronic components.

Right...evidence is needed in other words.

There are major segment of folks, especially here at ASR, who question whether people can hear difference as opposed to simply imagining them.

Because there is generally no actual evidence that they can.

For example, I suspect harmonic distortion spectra correlate with sonic qualities often described as warmth, musicality, and layered imaging.

Great starting point. There are many here who can help you create a testing process that can generate the needed evidence for further exploration.

Until then, there is an abundance of anecdote, with precious little evidence.

I notice a tendency in some quarters to simply deny the audibility of whatever may be causing these perceived qualities rather than scientifically explore what is causing them.

Those quarters tend to need...you guessed it...evidence...before chasing windmills.

 

[dfuller]

Example?

1 moment, need to go dig through Stereophile's reviews.

 

[PierreV]

I'm not an engineer or any sort of scientist, so I can only speculate.

Speculating about the possibility that as of now non-measurable differences could potentially result in audible differences is not worth consideration until the existence of the audible difference has been rigorously demonstrated.

It is not as if we were examining some strange correlation such as audiophiles having a lower life expectancy than the average population, in which case an open-ended investigation could be warranted and a full examination/analysis of possible confounding factors should be done.

Here we have nothing, except for feelings and random thoughts on the Internet.

My own unchanged systems can sound wonderful or awful to me, depending on the day/mood. In some cases, this is a huge subjective difference.

I have only two options here

1) something has changed in the way I subjectively experience music. Usually described as "I am in no mood for..."
2) some mysterious unmeasurable physical process has significantly perturbed my system.

Which one is the most likely?

 

[dfuller]

Example?

Looks like there are a few that have a bit more than a 0.1dB variance, but that's about as wide as solid state gets. Tube, on the other hand, gets higher, +/- 0.5dB or more.