i dunno what ur exactly doin here.... but for ur amplifier, that thing draws almost no current so run some 12 ga wire from ur battery (dual conductor), put a small inline fuse maybe 5A above what the fuse is on ur amp 12 inches from the...
try running the sub from a different source, like a portable cd player or something, something not pluged into the same outlet, if it stops, u probably got a ground loop, go buy a ground loop isolator from walmart lol its alittle...
bi wiring doesnt do anything at all, bi amping does, but like john i really dont think bi amping from ur receiver is gonna do much, but go get another power amp and u might hear a difference i dont know, that also depends on ur ears, u...