Quote Originally Posted by hermanv
I guess it matters what you mean by evidence. To me, common sense says that if I am listening to an artificial placement of a vocalist then how do I know my speaker set up is correct?
Here is were I think you are missing a huge point. It is very difficult to have a vocalist centered naturally without panning. If you try and record using two microphones to "center" the vocalist naturally, you run into bleeding, or phasing issues. And if the vocalist moves too close to one of the microphones, then the image will wonder between channels. If the vocalist is panned correctly, then it will be centered correctly and you will know that your speaker is correctly setup. A center vocalist is nothing more than a signal that is playing in both channels with equal amplitude and phase. That can be done acoustically or electronically with equal results.


The problem is nuch the same as trying to hear distortion on your amplifier while it is playing an electronic guitar recorded with a Fuzz box, your ears are incapable of seperating near end from far end distortion.
That is easy, don't use a guitar with fuzz to try in identify distortion in the amp. Use something else!

By adjusting your speakers you can move the apparent location of the lead vocalist to a number of places on the stage. If the recording engineer has also moved the lead vocalist around you have no way to tell which of you got it wrong. I know the previous is over simplified, but the inherent problem is; you must use a known good source to evaluate equipment.

Garbage in, garbage out.
Well you actually cannot do that. If you move the left speaker far enough away from the right one the sound will break apart. Even if the recording engineer panned the vocalist slightly off center, the mastering engineer can fix it. A recording engineer who has his lead vocalist moving all over the soundfield is incompetent. That is not the problem of the technology, but the person using it.

Very few of us have access to the master tape, so how do you know what is pristine source and what is not?