Had a new powered sub (Rockford Fosgate P300-12") running from a Pioneer Deh-80prs for three weeks. Replaced the four stock Toyota speakers and am running them in pairs from separate 60-watt Kenwood amps - they sound fine - but the sub isn't working. Adding to the mystery is that the manual says the power light is green and the protect light is red, while my light is blue. I've switched wires to the other amps, and they all work except the sub. I believe the sub is 2-ohm, but so is the built-in amp, so I guess it shouldn't matter that the hu is not 2-ohm stable since the sub's not powered by the hu.
Also, sometimes the sub plays, but it's always too loud, but strained, if that makes sense. Naturally, it played fine until now it's too late to return it. I could use any insight I can get. Thanks in advance.