Originally Posted by abneyxstar
I was getting pretty loud with my stereo this weekend and the sub stopped working. Everything else as it pertains to stereo is working just fine and I did not here anything that would make me think the speaker blew. There is nothing coming out at all. Is there a fuse or something I can check?
Pull the sub and measure across the terminals with a multimeter. You are looking for a DCR that is anywhere between 80 to 100 % of the stated impedance. Make sure that the woofer still moves and is compliant. If the woofer voice coil is open or the woofer is frozen then look no farther. Keep in mind that thermal damage can be accumulative with no major noise coming from the sub while being driven. Check the terminations inside the enclosure. Check the braided leads from the woofer terminals leading to the voice coil. If you do not have a meter ($10+) then test the disconnected sub with a quick pulse from a 9V battery. If the sub seems to be operational then move upstream to the speaker wire and the amplifier. If the amplifier is multi-channel and driving other satellites that play fine then check for an AC voltage with a multimeter on the sub channel output. If you get a voltage then the problem is elsewhere. If you do not get a voltage then the issue is isolated to that channel. Keep in mind that a supply fuse or internal protection circuit is likely to govern the entire amplifier and not just a portion. If you have a dedicted sub amplifier then check for AC voltage from the RCA source, check for AC voltage on the amplifier output, and check the supply DC voltage (a solid 12.0 + volts) across the amplifier primary supply terminals including the remote turn-on lead. Check all physical connections. Check fusing. Check for a status indicating LED on the amplifier per the amplifier manual.
If you invest in a multimeter and learn only three settings you can conclusively isolate the true problem in no more than 20 minutes.