3 ms·

The existence of the moon is not a metric someone invented. It can be detected by many (at least 5 available to general populace) means, its shape and features

The existence of the moon is not a metric someone invented. It can be detected by many (at least 5 available to general populace) means, its shape and features too. Stop making bad analogies and howaboutism. Our "distortion metrics" are barely validated garbage that has not been corrected since 60s. (Including THX standard which uses them, a pretty funny joke. It does better at room and speakers.) Hence, they are only useful as a check not a rating. We do know what sounds good, obviously it is an application of a bass boost knob. /s What's under the question is what sounds accurate (or accurate enough) and high fidelity. And the metrics we have typically do not answer it in the positive, only in a weak negative. People designing amplifiers typically do not chase these numbers too hard either, since that ends subjectively audibly poorly. We do not happen to have perfect amplifiers, it turns out. The metrics are not psychoacoustic for one, nor have been correctly validated. Better ones have been proposed but not applied. There are some definitive statements like "distortion 80 dB lower than signal cannot be heard in headphones" but there's no validation of it. (Plus it seems suspicious compared to what we know about psychoacoustic masking and absolute thresholds of hearing. Plus time domain behavior might be audible too in some cases, we just don't have an audio metric for that.) Some people have taken to plotting harmonic distortion graphs for multiple orders separately already, but it is way rare and still hard to interpret and it still does not differentiate audibly different (and differently annoying) kinds of distortion.

JohnBooty 4y ago
My goodness. How spectacular of you to claim this area hasn't been researched! There has been massive amounts of research on the audibility of various aspects of audio reproduction. Literally tens of thousands if not hundreds of thousands of papers. For starters: https://www.google.com/search?q=audibility+site%3Aaes.org https://www.google.com/search?q=audibility+site%3Aaes.org https://www.google.com/search?q=preference+site%3Aaes.org https://www.google.com/search?q=preference+site%3Aaes.org This discussion is over.
- AstralStorm 4y ago
  Oh come on. I namedropped AES papers almost by name. (The response to it in particular.) And definitely by name in another post. Nobody uses that metric, because industry Does. Not. Care. It's also still an integral unvalidated metric - it has not been subjected to listening tests to evaluate the thresholds nor figure out its limitations. If I missed a paper, point it out in a less lazy way. The last one that did something was in 1984 by Edward Cherry with a funky tunable distortion generating ampliifer. Even that was not a panel evaluation. There are more or less two benchmark quality amplifiers out there (I know of, and happen to be Benchmark) done by chasing the numbers, oscilloscope traces (because metrics are insufficient), a lot of modern error correction maths (90s era) in addition to validation by ear. I gave up trying to decode their feedforward plus feedback topology in detail, it's hard and not the usual example. These cost serious money. Trades some power efficiency too. One could use one of these to evaluate any and new metrics more easily, but nobody does that.

JohnBooty 4y ago

My goodness. How spectacular of you to claim this area hasn't been researched! There has been massive amounts of research on the audibility of various aspects of audio reproduction. Literally tens of thousands if not hundreds of thousands of papers. For starters: https://www.google.com/search?q=audibility+site%3Aaes.org https://www.google.com/search?q=audibility+site%3Aaes.org https://www.google.com/search?q=preference+site%3Aaes.org https://www.google.com/search?q=preference+site%3Aaes.org This discussion is over.

AstralStorm 4y ago
Oh come on. I namedropped AES papers almost by name. (The response to it in particular.) And definitely by name in another post. Nobody uses that metric, because industry Does. Not. Care. It's also still an integral unvalidated metric - it has not been subjected to listening tests to evaluate the thresholds nor figure out its limitations. If I missed a paper, point it out in a less lazy way. The last one that did something was in 1984 by Edward Cherry with a funky tunable distortion generating ampliifer. Even that was not a panel evaluation. There are more or less two benchmark quality amplifiers out there (I know of, and happen to be Benchmark) done by chasing the numbers, oscilloscope traces (because metrics are insufficient), a lot of modern error correction maths (90s era) in addition to validation by ear. I gave up trying to decode their feedforward plus feedback topology in detail, it's hard and not the usual example. These cost serious money. Trades some power efficiency too. One could use one of these to evaluate any and new metrics more easily, but nobody does that.