My sub off make sound hummm when on position it no sound at all.

Looks like the capacitors on the amp are going.
If you hear a hummm sound when you turn it on without anything playing on it, then the capacitors are to blame for sure -> Time to replace the capacitors.

Have you tried leaving the gas cap loose? Also you didn't say how many miles or what model but newer cars have cam position sensors, crank position sensors, map sensors, TPS , etc. My first thought is a worn throttle position sensor or a vacuum hose leak to one of the sensors.

If it's a single voice coil, it's probably 4 ohms. the sub only handles about 175w RMS, so don't expect earth shattering bass to come out of it. A single voice coil is easy. Positive from the amp to the positive post of the sub, negative from the amp to negative post of the sub. This sub sounds lots better if it's in a sealed enclosure. A ported enclosure allows too much cone movement, heating up the coils, and the sub fails prematurely. Hope this helps.

Phase reverses the polarity of the driver so it can be matched to the other speakers and bass-reinforcement characteristics of its position in the room. You don't want the sub 'sucking in' while other speakers are 'pushing out' or a bass cancellation will occur.

Set it, listen to bass from your normal seating position, reverse it and observe if the bass gets subjectively better. Leave it in the 'better' position.

Cutoff is a variable for the highest frequency where the speaker 'cuts off'. You can experiment with adjusting it for what sounds to you like the smoothest transition betwen the sub and the othere speakers. You don't want a lot of audible overlap where the sub and other speakers are acting on the same frequencies. It may sound to bassy in that area.

Try a different cable, make sure the cable you are useing is not a" twisted pair technology" cable, I have had that type of cable create a hummm in many subwoofers that I have troubleshot. Good luck !

Hello montez1599,

That's a great amp.

You do not say what subs you are connecting or what wiring configuration you are using. But there should be no problem if the amp is powering up normally. I'd check the gain and crossover settings to make sure they match the subs.

Having 2 +'s and 2 -'s is just a convenience for connecting more than one sub to the amp. If you have just one sub, connect to either of the positives and either of the negatives (they're connected internally). If you have 2 subs, you can run separate wires to each sub or you can wire the subs together and then run just one positive and negative to the amp.

Hope this helps.

try reconnecting your rca's from the deck to the amp when finished wire one speaker positive to positive on left channel and negative to negative on right channel then connect the 1st subwoofer. if all power and sound is fine and working turn off power to amp and connect negative terminal of 1st sub to positive on 2nd sub and positive from first sub to negative on second crossing the wires runs the speakers in series another way to try is parralel the speakers wiring by connecting positive left channel output of amp to positive on 1st sub same with the negative then splice positive to positive on second sub and same with negative.

you most likely mess up you wiring... im not sure what ohm resistance your subs are, but if its 2ohm or 4ohm you wire straight foreward one sub all positive wires to left positive, all negitive to left negitive, and the same with sub 2 to the right terminal. BUT if your subs are 8ohm then wire it with all positives from both subs to LEFT positive and wire all negitive wires to RIGHT negitive... and see if that helps and good luck!

IT'S YOUR DRYER MOTOR,IT'S SO WEAK IT WILL NOT TURN OVER,YOU MIGHT FIND A CHEAP ONE ON EBAY-MIKE

try hooking up your subwoofers in series. then connecting them bridged to the amplifier. as follows: positive from sub#1 into positive of amplifier left channel.. negative sub#1 into positive sub#2. negative sub#2 into negative amplifier right channel. turn the gain down as this will sound pretty loud.