Okay so for quite some time I've had a Pioneer stereo deck hooked up to an 500w RMS Alpine mono amp and a single Pioneer 10" sub. The whole setup was working great until today when I hooked up a second Pioneer 10". The wiring doesnt seem to have any issues, and the amp light turns on with the car, but I'm getting no bass from the subs. I didn't change any of the settings on amp or the deck, and everything seems to be right, but still nothing from the subs. I'm thinking that something is wrong with my deck, but it is functioning totally fine other than that, ad everything was fine before I disconnected the amp to install the second sub. Any thoughts as to whats wrong?