well,

now the 7500 is driving the center and two rears. But get this, the hum exists only in the center (as it always had) and only ONE of the rears.

And one question I just noticed: I own the Outlaw PCA interconnects to wire all of my speakers to their amps. The have arrows that indicate which direction the signal should travel. All of mine are correct, however, some of the cable have red lettering and some have blue. Does this mean anything?