What are the technical characteristics of an amplifier that define "soundstage"? And what are acceptable limits for human ears?
Phase response is apparently a non-issue in solid state amps but I know for a fact (and from experience) that tube amps require a lot of care to minimize delays.
I've also heard that channel separation of 30dB is more than acceptable for our ears. I don't know if this is true as I have never researched it. But it's not uncommon for amps to have a channel separation of at least 90dB.
What most of us know/believe is that the weakest links in objective measurements are the speakers and the environment. Some audiophiles cringe when they read a THD spec on an amp of 0.05% and look for a better amp. They forget that a typical speaker has a THD of 5% throughout most of the audible frequency band at real world listening levels. And I feel sorry for those that crank their systems because speaker THD rises to the point where the ears get over-whelmed with distortion. And most speaker sonic attributes are forever changed when pushed too hard.
Take a look at the phase response of all speakers out there. It's not uncommon for the phase to vary between +/-45 degrees. I would love to see a receiver that compensates for a speaker's phase response.
Add the room to the system equation and you have a God-awful mess on your hands
. I guess technologies like Audyssey are trying to address this but it will take at least two decades I'm sure before affordable systems that can totally compensate become avaialable.
We created this mess; we will have to bail ourselves out. This wasn't a problem 131 years ago when music lovers had only the choice of listening to live venues. This is just another fine example of how, throughout our history, we've sacrificed quality for convenience and safety.
