solderdude
Grand Contributor
I will just repeat what I wrote earlier and am quite sure this is what Dr. Olive is talking about.
There simply is no single number that can capture signal fidelity. The closest thing could be something like PK metric but that should also have AI to analyze the null with perceptional algo's.
Then again ... that, at least for amplifiers, might need to give a range of numbers it falls in with different loads.
With DACs you might need a range of numbers for 0dBFS and say -1dBFS program material so again... not a single number.
Then one would need to understand how you personally can relate to those numbers, in other words below which number you might hear audible degradation related to signal fidelity (excluding frequency response).
So ... one can dream on with wishing there will even be a single number that actually says someting.
Case in point: Some folks prefer tube amps that substantially modify the original signal and that effect should also be included in that single number.
What sounds nice to person A may not be nice to person B and may or may not measure well. How can you fit that in a single meaningful number applicable to all ?
The biggest problem with using the word 'distortion' is that there are many kinds of distortion and the threshold of audibility differs with test program material (music, tones), type of distortion and listening level (SPL) and training of the listener(s).
There is no single number that can describe all these variables. That makes distortion measurements pointless in regard to perception.
There simply is no single number that can capture signal fidelity. The closest thing could be something like PK metric but that should also have AI to analyze the null with perceptional algo's.
Then again ... that, at least for amplifiers, might need to give a range of numbers it falls in with different loads.
With DACs you might need a range of numbers for 0dBFS and say -1dBFS program material so again... not a single number.
Then one would need to understand how you personally can relate to those numbers, in other words below which number you might hear audible degradation related to signal fidelity (excluding frequency response).
So ... one can dream on with wishing there will even be a single number that actually says someting.
Case in point: Some folks prefer tube amps that substantially modify the original signal and that effect should also be included in that single number.
What sounds nice to person A may not be nice to person B and may or may not measure well. How can you fit that in a single meaningful number applicable to all ?