comb filtering is the most plausible explanation for many of the differences people claim to hear from cables, power conditioners, isolation devices, low-jitter external clocks, polarity reversal, ultra-high sample rates, replacement power cords and fuses, and so forth. Comb filtering is a specific type of frequency response error that occurs when direct sound from the loudspeakers combines in the air with reflections off the walls, floor, ceiling, and other nearby objects. Ask yourself, do I sit in the same spot every time? The answer will not surprise us because it most likely is NO.Unless you strap yourself in your chair and its bolted to the floor we do not always sit in the same place.This just might be the reason for comb filtering, moving even a tiny distance changes the response by a very large amount at mid and high frequencies..
