I don't want to beat a dead horse but I'm bugged.


I just can't clear my head of this. I don't want to start a measurements vs listening war and I'd appreciate it if you guys don't, but I bought a Rogue Sphinx V3 as some of you may remember and have been enjoying it quite a bit. So, I head over to AVS and read Amir's review and he just rips it apart. But that's OK, measurements are measurements, that is not what bugs me. I learned in the early 70s that distortion numbers, etc, may not be that important to me. Then I read that he didn't even bother listening to the darn thing. That is what really bugs me. If something measures so poorly, wouldn't you want to correlate the measurements with what you hear? Do people still buy gear on measurements alone? I learned that can be a big mistake. I just don't get it, never have. Can anybody provide some insight to why some people are stuck on audio measurements? Help me package that so I can at least understand what they are thinking without dismissing them completely as a bunch of mislead sheep. 

128x128russ69

 Would the issue be that you don't want accuracy?  You want artifacts?  I think that is the conclusion that can be drawn.  

Well, you're free to draw whatever conclusion that you would like.

My pursuit and objective  in home audio  has not changed in 30 years. I want to obtain the most natural and realistic music reproduction that I can hope to reasonably achieve. Actually listening to audio products and judging what I hear is the most effective and dependable process to achieve this goal. 

Measurements tell me next to nothing in regard to how these audio components will sound,  so I must hear them. I totally understand if others judge and select differently with buying audio components.  Do what suits you the best. 

Charles 

@realworldaudio , I feel most of what you wrote is made up. I don't think you will be able to clearly articulate what is missing from the measurements and certainly not 95% of the things that are missing. Perhaps this is the issue. This sounds more like outrage mob mentality that reasonsed criticism. I am welcome to be proven wrong.

@deludedaudiophile 

I came up with the 95% missing using historic precedents for scientific discoveries. (Throughout history the narrow minds all firmly believed that everything that could be invented was already invented, and now even a 6 year old kid knows it better.) The practices for audio gear measurements are relatively new (just a few decades old). In even 50 years, our practices will be proven as massively inaccurate, and in general quite useless as it probably covers about 5% of what our children's children will count as measurements that point towards sound quality perception. Although that will be in the future, yet it does not detract from the reality that our current practices are in their infancy. To think we know everything, and we have discovered all the secrets to sound and audio gear is the only sure bet to loose. Doing a google search will do no good now, but will help in 50 years. Also, if google search would answer deep questions on audio measurements, we would not have this discussion, and everyone would be at perfect agreement.

(BTW the 95% is just a symbolic value, please do not start a thread on whether it is 92% or 96.786734% exactly, or it's truly 57.4%... only time will tell, and although our view will change decade from decade, but the reality will be still the same: today we have a very limited concept of how to measure audio parameters to reflect on sound quality.)

So, a few examples on issues with current standard measurement practices that I know of, I will take only amplifiers for now:

*all parameters tested on non-inductive perfectly passive extremely simplistic loads, while the loudspeakers are highly complex live loads affected by the room.

*Only additive distortion is measured, subtractive distortion is not.

*Change of THD in function of output level and frequency are no paid attention to, while these are strong determiners in relation whether the sound is perceived as natural VS manufactured.

*Amplifier behavior is tested with constantly repetitive primitive signals, while the music output is a highly variable extremely complex waveform.

*It is not examined how an amplifier deals with small signals following a large pulse at the frequency extremes.

 

I mentioned the names of known and proven audio authorities in my initial post, because they have the answers you want from me, but I have no credibility in your eyes, so it's a waste from me to yap around. Do not believe me, as you do not know who I am, and that's fine. 

I just humbly point out to you (again), to listen to interviews with the fathers of audio measurements and high end industry and hear what they have to say. Thank you for the chat. I hope I have answered your concerns. What I wrote might be completely irrelevant to your quest, and it's quite likely that you have specific experiences that point you in the direction you want to go, where you will find fulfillment and purpose.

However, ignoring the experts on audio measurements will quite likely lead to a more protracted learning curve than what you are looking for. I wish you success and luck!

If it sounds more like a live performance, but isn't accurate by measurement standards, then what would be the point of accuracy if it doesn't sound closer to a live performance.

Great post!

I will only add that we cannot know how to measure and how to interpret these measures correctly if we dont have a correct model of human hearing at the end......

That was the subject of my last 3 posts here.... With some interesting  scientific articles about hearing ....

@deludedaudiophile

I came up with the 95% missing using historic precedents for scientific discoveries. (Throughout history the narrow minds all firmly believed that everything that could be invented was already invented, and now even a 6 year old kid knows it better.) The practices for audio gear measurements are relatively new (just a few decades old). In even 50 years, our practices will be proven as massively inaccurate, and in general quite useless as it probably covers about 5% of what our children’s children will count as measurements that point towards sound quality perception. Although that will be in the future, yet it does not detract from the reality that our current practices are in their infancy. To think we know everything, and we have discovered all the secrets to sound and audio gear is the only sure bet to loose. Doing a google search will do no good now, but will help in 50 years. Also, if google search would answer deep questions on audio measurements, we would not have this discussion, and everyone would be at perfect agreement.

(BTW the 95% is just a symbolic value, please do not start a thread on whether it is 92% or 96.786734% exactly, or it’s truly 57.4%... only time will tell, and although our view will change decade from decade, but the reality will be still the same: today we have a very limited concept of how to measure audio parameters to reflect on sound quality.)

So, a few examples on issues with current standard measurement practices that I know of, I will take only amplifiers for now:

*all parameters tested on non-inductive perfectly passive extremely simplistic loads, while the loudspeakers are highly complex live loads affected by the room.

*Only additive distortion is measured, subtractive distortion is not.

*Change of THD in function of output level and frequency are no paid attention to, while these are strong determiners in relation whether the sound is perceived as natural VS manufactured.

*Amplifier behavior is tested with constantly repetitive primitive signals, while the music output is a highly variable extremely complex waveform.

*It is not examined how an amplifier deals with small signals following a large pulse at the frequency extremes.

 

I mentioned the names of known and proven audio authorities in my initial post, because they have the answers you want from me, but I have no credibility in your eyes, so it’s a waste from me to yap around. Do not believe me, as you do not know who I am, and that’s fine.

I just humbly point out to you (again), to listen to interviews with the fathers of audio measurements and high end industry and hear what they have to say. Thank you for the chat. I hope I have answered your concerns. What I wrote might be completely irrelevant to your quest, and it’s quite likely that you have specific experiences that point you in the direction you want to go, where you will find fulfillment and purpose.

However, ignoring the experts on audio measurements will quite likely lead to a more protracted learning curve than what you are looking for. I wish you success and luck!

 

@realworldaudio , I am not an EE, but my I have an advanced physics degree, and have worked in semiconductors, batteries, and development and measurement of those a long time. I have gotten pretty good with metrology out of necessity. Hence I don’t claim to be an expert, but I think I have a good grasp of what is being communicated in the measurements:

*all parameters tested on non-inductive perfectly passive extremely simplistic loads, while the loudspeakers are highly complex live loads affected by the room

Stereophile specifically mentions they use for some of their tests a synthetic speaker load that models a real world speaker. This appears to negate some of the above statement. Testing into 4 ohm is standard. Testing in 2 ohms seems common. This will provide insight into more reactive loads. Testing with worse case synthetic loads is common and harsher than real world conditions. For characterizing semiconductor devices we test with synthetic loads to find the "corners" for stability.

 

*Only additive distortion is measured, subtractive distortion is not.

 

I am not sure exactly what you mean by subtractive distortion. Are you stating that the interaction of a particular amplifier with a particular speaker may result in lower overall distortion? This seems possible. I will note that @atmasphere who seems to know his stuff stated most (not all) speakers are designed to be driven with a voltage source which may negate the advantage you may perceive for most listeners. This would be dependent exclusively on the load (speaker) so I don’t see how this could be tested.

 

*Change of THD in function of output level and frequency are no paid attention to, while these are strong determiners in relation whether the sound is perceived as natural VS manufactured.

This is purely false. Read any of the more recent reviews on ASR. THD and SINAD is tested from very low power to very high power across a range of frequencies from I think 20Hz to 15KHz. I am too lazy to go verify the exact frequencies used.

*Amplifier behavior is tested with constantly repetitive primitive signals, while the music output is a highly variable extremely complex waveform.

This is also purely false. ASR tests with a 32 tone IM signal. This is 32 tones from low frequency to high frequency. That would result in a signal that is complex and varying in amplitude as the frequencies add together.

 

*It is not examined how an amplifier deals with small signals following a large pulse at the frequency extremes.

I will not call this false, but I think you are not interpreting what the other measurements will accomplish. The 32 tone IM signal will vary from large to small. The THD stimulation also transitions from a very small level to very large. If the measurement is -100db in both cases then that would also be the case for the special condition you are theorizing.

What may be missing is testing if the distortion rises under continued heavy load causing device heating. I do not know if that is a valid real world condition.

I have listened to Nelson Pass. He strikes me as very much a heavy measurements guy. He may tune intentional artifacts in his designs, but what I have read and what I have been on Youtube indicates he is very much measurement oriented.