I've got an old 12" car sub in a sealed box, and I have just tried hooking it up to an amp, but it's not very loud. I've connected it to the amp correctly (bridged it as per the instructions, and connected LFE RCA to correct input), and the amp is meant to do 130W into 8 ohms. The subwoofer is 12", 300W RMS, 2x 4 ohm coils I wired in series for 8 ohm, and 88.1dB sensitivity. If I have the sub amp on like 80% volume, it's making bass, but the little yamaha I was using before with its 8" ported woofer and 75W RMS is louder at only 30% volume. Any idea what the problem could be? Maybe just too insensitive at too low power? If I didn't wire the coils up in series but did parallel instead (I did this part weeks ago, maybe I had a brain fart) that would be a 2 ohm load, and would that have just caused the amp to blow? I will consider pulling the speaker out if there are no other options, but don't want to right now, it's old wood and who knows how much life the holes have left in them. Edit: Don't think it's that, as I just hooked up the multimeter and it flickers between 7 and 8 ohms, as expected.