Car Stereos: car stereo, rca cables, 4 ohms

Question
my amp is powered up and it was powering both subs, then one, now nothing. amp still has power. i re ran rca cables from head unit to amp to no avail. what might the problem be????

Answer
Hi Bret,

It could be any number of issues.  The first thing I'd check is to disconnect the subs and connect a regular speaker -- see if you get sound back.  If you don't, then you might be dealing with blown subs.

If you have a multimeter, check the impedance being provided to the amplifier.  It must be at or HIGHER than the amp is rated for (ie if the channel is capable of 4 ohms, 4 ohms, 6 ohms, 8 ohms, 16 ohms are OK.  2 is not.)

If the amp's light is on, that only means it has power.  It doesn't necessarily mean it has signal or it is functioning internally.

If you have a laptop with a 1/8" to RCA output, you could use it to test the inputs on the amp to rule out the deck/wiring.

Justin