Car Stereos: Amp problems, audiobahn a2300hct, kicker l5

Question
QUESTION: I had a single 12" alpine type r sub powered by a kenwood 800 watt amp in bridged mode that worked fine for months and then one day the amp kept going into protect. The strange thing was that every now and again it would come out of protect and work for a while and go back into protect. I suspected the amp at first and took advantage of a deal from my friend and got 2 15" kicker L5's powered by an audiobahn a2300hct amp in bridged mode. I heard these subs in  my friends car and they worked perfectly. The day after buying them i installed them in my car and they worked for a few minutes and the amp went into protect mode. I have tried running a better ground, checked the power wire and fuses as well as checking the remote wire and power wire to my head unit and nothing has worked and i am looking for some input on what may be the issue.

2 15" Kicker L5
Audiobahn A2300HCT
Panasonic CQ-C8413U

Thanks!

Mike

ANSWER: Hi Mike,

When you have an amplifier going into "protect" mode, it's usually (though not always) the result of an impedance mis-match between the subwoofer and the amp.  For example, with your Type R and bridged Kenwood amp, I'd have suspected that the subwoofer's voice coils were wired in parallel, resulting in a 2-ohm load, which is too low for most 2-channel amps in bridged mode.  This can also result from a blown or defective subwoofer; it there's a dead short in the voice coil, it's an extreme example of too low an impedance for the amplifier.  

This theory doesn't explain why the Kenwood amp would sometimes work for long periods of time, however; and it's somewhat less likely with the new system, because your Audiobahn amplifier was designed to be stable with a 1-ohm load in bridged mode.  However, one thing to try might be re-wiring the amp and subs so that you're using it in 2-channel mode instead of bridged.  This might result in lower power output, but as long as it plays loud enough for your tastes, the power isn't really an issue.  

Another thing to check, though it's something of a longshot:  many amplifiers will go into protect mode if the supply voltage is too high.  There's a possibility that your car's voltage regulator has a problem, resulting in the alternator producing too high a voltage level.  You can check this pretty quickly with a voltmeter; if you're getting voltage readings over 15v with the engine running (you might want to rev the engine while testing) then have your charging system checked.

Hope this helps!

Brian

---------- FOLLOW-UP ----------

QUESTION: Ok Brian ill give you an update. I have since tried a couple things. I took out the head unit and ran a separate ground power and remote wire through the car and only hooked the ground power and remote wires to the amp so that the only things running in the car was the head unit and the amp and it still went into protect mode. Do i have a cursed car or are there any ideas you can think of that may be problematic. And the volts at the battery with the car running did not peak over 14.5 volts.

Answer
Hi Michael,

If you didn't have any subwoofers connected to the amplifier, and it still went into "protect" mode, then that makes it pretty certain that the amplifier has a defect--especially if the voltage at the power terminals tested within spec.  I wasn't clear, from your question, on whether the subs were connected or not; but if they were, I'd try again without the subs connected.  An amp that triggers a protect mode with no subs connected must have an internal short.  On the other hand, if it's only happening when the subs are connected, then you can't rule out a problem with the subs.

Good luck!

Brian