I have a Sundown Audio SAE-1200 amp running 2 SA15s. I'm having a problem getting sound out of my subwoofers. At first I had a Pioneer 4100 DVD when this first started happening. The Subs would cut in and out, then finally stayed off but the amp stayed on. So i had my local shop check the voltage and they said no power was going through my rca's. So I had a different cd player and installed it. After I installed it everything was working fine again. Then today the subs started going in and out. Right before the subs went off, it sounded like the subs were crackling but still had sound going through them. So i turned down the radio and they stopped working after i tried turning the volume back up. I changed out rca cables and still nothing. The amp still has 12.5 volts or high from the power wire.

Process of elimination.

Check to verify the RCA cables have voltage. Check to make sure the fuse isn't blown. Check your speaker wire connections. Check to make sure the REM wire has 12V.

That's in no particular order. But some things to check.