Why your pan control doesn't really work
You know how the pan control works... turn it to the left and all the sound comes from the left speaker; turn it to the right and all the sound comes from the right speaker; turn it dead center and the sound appears to come from a point exactly between the speakers (if your system is set up properly).
Works so far...
But now, try turning the pan control half left or half right. Where does the sound come from now? Listen carefully and you will be able to imagine the sound coming from an area towards the left of the space between the speakers, or the right if you panned that way. But you'll have to listen carefully to hear this effect, even if your system is good and well set up.
So how come the pan control works well for hard left, center and hard right, but not so well for in-between settings?
The answer is in the way the brain perceives direction. If a sound comes from the left, then it strikes the left ear directly. The right ear also hears the sound but muffled by the acoustic shadow of the head. The pan control mimics this quite well. But also, a sound coming from the left strikes the left ear first, then reaches the right after a short delay. The brain is very sensitive to this time-of-arrival difference, and the pan control does nothing to mimic this.
So the three positions that do work...
- Hard left: the sound comes from the left speaker only, exactly as it would if there were a single real sound source on the left.
- Hard right, similar to the above.
- Center: the sound reaches both ears from both speakers at the same level and at the same time, just as would happen with a single sound source directly ahead.
In all other positions, the mimicry is partial.
You might think it would be a good idea for the pan control of a mixing console to include delay as well. In fact, in a digital console there is no reason it couldn't be provided. However it turns out that it causes more problems than it solves, the key problem being what happens when your recording is played in mono. And of course mono will be important to you if you ever expect to get your recording played on TV.
How would the perfect pan control work? Tell us what you think.