Hooked up an amplifier and two woofers to my car stereo. the amp powers up but no sound comes out of the woofers. they work when hooked up to the stereo directly but not when i hook up the amp...what am i doing wrong?

FIRST OF ALL --- THERE IS A FEW THINGS YOU NEED TO KNOW BEFORE HOOKING UP
A WOOFER LIKE THIS ---- IS THIS A STORE BOUGHT POWERED SUB WOOFER ? DOES IT HAVE IT'S OWN CROSSOVER BUILT INSIDE ?? I WOULD GUESS IT NEEDS TO BE HOOKED
UP TO A SUB WOOFER OUTPUT FOUND ON THE BACK OF THE IN DASH PLAYER ..
THE WOOFER NEEDS TO RECEIVE ONLY LOW FREQUENCY AUDIO WHICH MOST OF THE NEWER CAR STEREOS PROVIDE BY AN RCA JACK ON A SHORT WIRE COMING OUT OF THE STEREO ...
IF YOU TRY AND TAP IT TO FULL RANGE SPEAKERS THAT ALREADY ARE CONNECTED TO AN AMPLIFIED SIGNAL THE SOUND WILL BE DISTORTED .......
POWERED SUB WOOFERS NEED A LINE LEVEL INPUT WHICH IS MUCH LOWER THAN SAY
SPEAKERS ALREADY RECEIVING AN AMPLIFIED SIGNAL.
POWERED WOOFER WILL ALSO NEED TO HAVE A 12 VOLT ELECTRICAL CONNECTION AND A GROUND WIRE TO OPERATE THE AMPLIFIER BUILT INSIDE.
IF YOU HAVE NO EXPERIENCE WITH THIS TYPE OF HOOK UP I WOULD STRONGLY RECOMMEND SOMEONE WHO DOES [ CAR AUDIO SHOP ]

The six 1/2 speakers are your woofers,connect the positive and negative wires from the speaker to the 2 connections labeled on the crossover as W(woofer)+ pos and W(woofer) -- neg,hook the tweeters to the crossover connections labeled T(tweeter)+ pos and T(tweeter) -- neg,then hookup the 2 remaining connections labeled Amp to your amplifier,amp must be 2 or 4 channel stereo capable and give out enough power to properly drive the speakers so they achieve optimal performance.

If your sub woofers are SVC (single voice coil) 2 OHM each, then connecting one to each channel would make the amplifier run in 2OHM stereo Then again, if your sub woofers are 2OHM each, it would be better to connect both together in series and connect them to the BRIDGE specified speaker terminals of your amplifier making it run a 4OHM load into one channel. This will give you all the power the amp can give and still run stable. A 2OHM load into one channel will likely damage your amplifier. Do not forget to set the LPF (low pass filter)on if you are going to use the amplifier to run sub woofer/s. dreamsystems

No use the head units wiring for the speakers use amp only for subs

IT MIGHT BE A BAD WOOFER, AMP.. WHAT YOU CAN DO IS PLUG THE AMP UP WITH NO WOOFER AND THEN SEE WHAT HAPPENS AND THAN PLUG THE WOOFER UP AND IF AMP GOES TO PROTECT THEN ITS WOOFER IS BAD AND MAYBE ITS VOICE COIL

check your amp fuse also any car fuses, then check inside the sub box at the connections as they dont come connected when you buy it, try that 1st

This amp (kenwood  819)  was designed for use with a sub-woofer, hence the single chanel. It will however power up 4 speakers in mono, and if they are capable of handling the amps.while robbing you of the benefits of stereo as well as left, right and fade control.Good luck...
If you still want it connected. You should purchase an amp installation kit, and review the topics and videos at this web site. www.installdr.com

Good luck...

I would double-check your RCA's on the amplifier. You should hear a thud if you unplug them. If not they are either not hooked up or defective.

You need to check your woofers. Most likely one or both may be a) blown or at a dead short or b) the ohm rating on them may be too low. What model woofers and amp do you have??

Hey Yoo,

 

Go to Radio shack and get you an adapter that will take an earphone jack and convert it to RCA male.  You use this to simulate the signal coming from the reciever.  Hook up to a Cd player or Walkman, anything with an earphone output jack. Test that the device actually puts out music or anything worth listening to.  Connect the device to the input of your amp, with the car running, and the reciever turned on.. This will tell yo if the signal is getting from the reciever to the amp. You may not be getting signal from the head unit. 

If you still get no sound to the woofers, dsisconnect the woofers and try a different speaker.  If that speaker dont work,  Change setting and switches., and if you still get no sound, then your amp is toast.