I`ve got two amps. One is an Alpine MRP-M1000 and one is an Alpine MRD-M1005. When I hook up the 1000 I get sound from my subs, when I hook up the 1005 I get no sound. The subs are wired for 2 ohms, which both amps can handle. What is wrong, do you think, with the MRD-1005