Another possible solution?
When I first hooked up my Def Tech PM 700s to my TX-DS797 2 years ago, I had a similar problem. Higher-pitched sounds- female voices, brass instruments, etc.- would cause a popping or snapping sound. As it turned out, I had both the re-EQ and upsampling turned on. Turning one or the other (in my case, both) off solved the problem. ------------------------------------------------------ My System: Onkyo TX-DS797; Pioneer Elite DV47-Ai; Def Tech PowerMonitor 700s (l/r); Def Tech CLR 2500; Toshiba 30" CRT (ab. 18 yrs. old!); JVC HR-S5400U SVHS VCR (on last legs); Microsoft XBox; Nintendo GameCube; Nintendo 64; old JVC jam box speakers for surrounds! (eventually Def Tech BP-Xs)