I have a way of looking at things .. my sixth sense guides me to building and modifying a system that is as accurate as I can get it. There are engineers who disagree, and that's fine. For the most part I think their work does a poor job of reproducing a musical performance, but I'm sure from their own perspective they think it does a good job.
To each his own.
Here is my thing
- My Premise #1: music creates experiences and feelings in listeners. If these are pleasant feelings, the listener wants to come back for more.
- My Premise #2: a recording is an attempt to spread musical experiences and feelings to more people at later dates and times
- (Note. Premise #2 does not require that all people experience music the same way or that the reproduction feels exactly the same as the original. Premise 2 basically rules out classes of other possibilities, like "recording exists to help people enjoy watching an oscilloscope", "recording exists to frighten people", "recording exists in order to push some distortion numbers toward zero". None of that is why recording exists. )
- My Premise #3: there is always distortion in the playback chain. From microphone to speaker, every device along the way adds at least a small bit of distortion. What's more, the playback is not creating the true wavefront heard at the microphone position, so the imaging in your 2-channel home setup is always going to be "faked" to an extent.
Okay, so we have distortion. Here are some examples.
- The violins are too bright.
- The violas are muffled.
- The bass is flabby.
These are descriptions of a human perception. But these happen to correlate fairly directly to simple objective measurements.
the violins are bright: might be caused by a tilted-up frequency response
the violas are muffled: maybe a dip in the f.r. around 3-4 KHz?
the bass is flabby: poor damping factor in the amplifier
Okay, that's great, but these are relatively simple "trees"-- but what of the forest, the Gestalt? Here's one possible gestalt factor:
British reviewers use the term Pace, Rhythm and Timing (PRAT). They observed that most music has a rhythmic quality to it -- it's not simply the beats repeating over and over.
The beats could
- Feel very insistent, demanding. Or be sneaky.
- Create a driving forward feel, or a laying back feel.
- Come at minutely different times and thereby make powerful musical/emotional expression. (the Time dimension of music conveys much intense feeling)
Furthermore, the quality could change throughout a piece. How well-differentiated are the different sections? Do they sound clearly different?
The PRAT accuracy of a system can't be reduced to one cause/effect. It emerges from many features.
The interesting thing is that when a playback system gets the PRAT wrong (relative to the original performance), it changes the perceived performance. It's not like a muffled viola, in which the listener can tell it's a muffled viola and still do their best to pay attention to the player's performance. But when a system changes PRAT it is changing the performance. A person may not be able to tell--- does the bass guitar sound lazy and late because the player was bad, or because the system messed up his playing?
So in my book it is critical to look at distortions first and foremost as distortions in performance, and only secondly as some individual "trees" (specific measurements).