[SierraMikeBravo]

I believe you can only change that by changing the absorptive properties of the room or the dimensions. I think what you are referring to is direct timing (the time it takes for sound to reach your ears directly from all sources) which is a function of distance. If it is not in sync, the waves will be out of timing causing a collapse in the immersive audio experience. The problem is, measuring with a tape measure doesn't always work. The DSP can induce a lag in time which Audyssey listens for and corrects.