Expert: Cleggsan - 3/13/2009

Question
I was running a JL audio w3v2-d2 bridged to a fosgate p3002 amp and it sounded good for about a day then it started cutting in and out and the amp protect light kept coming on. I assumed it was my speaker so i tried to hook it up to my friends amp and it didn't work so i thought it was blown, so i got a new speaker and it sounded even better a Kicker Solo barick L5. It only worked for about 30 min before same problem so i rewired the whole system and i could get the speaker to work only to a certain point once the gain or volume was raised the protect light on the amp would shut it down. So i hooked my friends amp up, and it worked fine. Something else you should know is that in trying to get the fosgate amp to work, when i pulled the red rca back tight i could get it to kick on and stat on as long as i held it, it would also work when the wire was unpluged. I tried the amp in his truck and it didn't work for his speaker, but when put into his wife's honda not bridged it worked fine. (I did try not bridgeing in my system it still didn't work) So i assumed it is the amp but i don't understand why the speaker didn't work in his tuck or amp and why it did in her car. What do you think the problem is and do you think my JL is blown and how do i tell? What do i do, is it possible a short in one of the rca jacks can be causing this? Tomorrow i am getting a kicker zx400.1 amp and i don't want to blow it or my solo baric. plus i will be devistated if my JL is blown. Any advice or input will be much appreciated. Thanks James

Answer
I kind of lost track of what was going on during your discussion.  But, based on what I understand I would venture the Fosgate is working just fine in the normal mode but has an intermittent or overload problem when it is in bridge mode.  Maybe the switch for bridge is not making contact all the way.  Or maybe you don't have the speakers connected to the right terminal when in bridge mode..  Check that out. Mis wiring or a short in the system can cause all these problems, too.

Also, watch the impedance match; if the speaker load is too low for the amplifier it will throw the amp into protection mode, also.

To check the woofer, just measure the dc resistance at the terminals of the sub. You will need an ohmmeter or good vom for that.  If you do not have one you can check the sub this way. Using a good D cell or 9v battery, using a couple of jumper wires, just connect the battery momentarily to the speaker terminals; the cone should move forward or inward slightly and you should hear a little thump when the connection is made.

Hope this helps.
C