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help - speakers cutting off


Well-Known Member
September 13, 2003
Reaction score
City, State
Pennsauken, NJ
Year, Model & Trim Level
97 Sport
yesterday i put my kenwood deck up all the way during a quiet song to see how loud it went, and its been acting funny since. i have a set of infinity components in the front, a set of midranges in the rear, and an amp/sub. so the problem is, if i turn on the unit, the 4 speakers will be fine for about 10 seconds then just go off, while the sub still plays.

any idea what is going on ?

ps i thought i should also add that the head unit (not the amp) powers the speakers.

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Not quite sure, but a few steps in troubleshooting:
-Try fading all fwd and all rear
-Try balance all left then right
-Try both at same time (ie all sound to right/front)
-While doing this adjust volumn through entire range
-These steps may isolate a failed speaker (a speaker that has blown and is "pulling down" the entire sound stage)

Well, post some more once you've tried this and let us know.

Naw. If the speakers start to play fine every time he turns his headunit on, it's most likely the internal amp, not the speakers. Only chance it's a speaker (and this is possible) is if the headunit was turned up so loud it clipped the audio signal. In a nutshell, clipping makes your speakers overwork themselves, and given enough time, WILL ruin them. If you fried a speaker's voice coil and shorted it, the headunit is likely going into a protection mode. If isolating one speaker doesn't work as the headunit shuts its amp down, you can measure resistance between each speaker's + and - wires. You could measure at the speaker, or what's probably easier is measuring each speaker at the headunit's harness. Make sure you check them all.

Yup, sounds like a shorted voice coil/speaker wire or you blew an output and it's trying to send raw DC to the speakers and the protection is shutting down although I don't usually see that kind of protection except on home amps ... be careful because raw DC will toast a voice coil real fast

Like the gentleman said, measure the ohms of each speaker at the head and look for a short or abnormally low resistance in one speaker, if they look OK then put a voltmeter on the output wires of the head unit and look for dc voltage, any more than a couple of millivolts means you have a shorted output IC/transistor ... that's why you hear most home stereos go click a few seconds after you turn them on, they look for DC on the outputs and only click in the protection relay if everything is OK

I wouldn't run the unit with any speakers hooked up when testing because as I said if it's sending raw DC to the speakers you can toast a voice coil very easily before the protection shuts it down ... then you'll have a blown output amp AND blown speakers to deal with

That's true... I was assuming (I know, I know an a_ _ out of me and you) that his unit would automatically self protect and shut down if his speakers clipped again. I had a similiar issue with my clarion head unit and the stock MACH audio door speakers... after I changed to the Memphis 5x7, I have not had an issue. Reading the DC resisitance of each speaker is the best option...... provided the guy has a multimeter (preferably a digital one since 4 ohms is quite hard to distinguish on an analog unit). Of course the Rat Shack has a $19.99 Digital Meter that would sufice for simple car audio applications. Well, keep us posted on your findings.

You can usually find a digital multimeter for around 5 bucks that will work just fine for most people, I keep one 'cheapie' in my car, one in my boat and one in my house in addition to my 'good' multimeters ....