I just installed a new subwoofer setup. Previously i had 1 MTX TT65 12" and a pioneer GM-5400T amp. I had NO problems with this setup whatsoever. Last night i replaced that with 2 Pioneer TS-SW2501 S4 subs(10" shallow) and a Pioneer GM-D8500M. The subs are rated at 4ohm, i hooked them up...