“When I say "measure everything we can hear" I refer only to those things that gear does to degrade audio fidelity. I am specifically not talking about psychoacoustics, such as how we perceive the "imaging" that's embedded in a recording.”
The gist of this is so scantily understood that your words are worth repeating (so I did).
As a signal purest, the goal is to amplify or do whatever job, without any alteration of the signal, a “straight wire with gain” as they used to say.
30 years ago, the ways one could analyze an audio signal were limited without a large budget and even then it was crude by today’s standards. When Dick Heyser resolved time delay Spectrometry, time analysis became somewhat easy, now there are a myriad of ways open to the investigator.
Many based on the same basic idea that you can compare the input to the output.
What has not changed is the need to learn from the appearance of measurements what specific features might sound like as well as their cause and correction.
I wouldn’t say unfortunately but the designer of equipment that is for others to use is more or less boxed into the position of being that purest too.
Some people aren’t aware that say their loudspeakers polar pattern or amplitude and phase response have driven their musical taste in one direction or another .
I mean in ones personal system, they could let their musical taste drive the colorations they have / tolerate.
At least when developing loudspeakers for others to use, you don’t want bias, when you have “something’ that makes one recording sound better, there will be other things that it makes sound worse. The path is normally to go towards the better measured one, it will have less effect on more music.
With loudspeakers it’s relatively easy as they are orders of magnitude less ideal than most electronics, there also one needs to look at ‘faster” events than with loudspeakers.
One area that is lacking I think is measurements that span a large dynamic range. I sat in at an AES chapter measurement seminar in Atlanta on Saturday and it struck me that while many domains are covered, we do not examine much dynamically.
With loudspeakers , there are a number of things which can effect what a loudspeakers does relative to the input signal.
Power compression is the most well known but there are a number of nonlinearities and hysteresis elements involved so even recent history effects the response, distortion etc, what they do, and nearly all these problems get larger / louder faster than the desired signal.
In blind testing, the difference I reliably heard between a number of amplifiers fell into two groups.
One group sounded fine except that with some very dynamic program material, the decay side sounded “granular” or stepped somehow as the signal extinguished.
The other group sounded essentially identical except the decay was smooth to the vanishing point.
The one very surprising thing we found was that at a point WAY below 0dB (like -20) on it’s output indicators, one smaller amplifier was instantaneously clipping.
I don’t mean traditional clipping but a cycle here or there on peaks and something I would not have guessed.
That was inaudible as a “flaw” until compared to a larger unclipped amplifier when the unclipped amp had a more dynamic sound. Again if there were a dynamic measurement comparable to music, this would have shown up (other than on the oscilloscope I got out to find the cause of the difference I mean)
Best,
Tom Danley
Danley Sound Labs
I think the truth lies with using both.
