Clarion DXZ735MP Head Unit Cutting Out

Hey guys, I just put a new head unit in my '97 Pontiac Grand Prix, and I need some help.

It's a Clarion DXZ735MP head unit, and when I turn the volume up loud (not excessively loud, IMO), the sound will start cutting out.  Never had this problem with the factory head unit.

Here's my system set-up:   Infinity Reference Series 5.25" components and crossovers up front, and Infinity Reference 4"s in the rear. Factory rear 6x9's removed. USAcoustics 100x2 amp running 300x1 into a MTX 12" 4 ohm sub in a sealed box. I've got in-line filters going to the front and rear speakers, I forget exactly, I think 150Hz up front and 400Hz for the rears.

At first I was using the power and ground in the factory harness, so I tried switching to dedicated power and ground.  I matched the wire gauge of the Clarion harness, 14 ga.  Should be enough for 17 Vrms x4, right?  Still have the problem. 

Disconnected the sub and amp in the rear, still have the problem. 

Played with the fade and balance, still have the problem.  Do I need to totally disconnect the speaker to determine if it's shorting out, or would moving the fade and balance be enough?

So, I don't know what else to look for.  Any suggestions?

Thanks,

Matt

I'm using the factory wiring with aftermarket speakers.

I replaced the factory 5.25" and tweeters up front with Infinity Reference Series components and crossovers.

In the rear, I removed the factory 6"x9"s, and replaced the factory 4" with Infinity Reference Series.

Thanks,

Matt

CruisinS&S wrote:

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sounds like you mine have the speaker leads out of phase somewhere. Did you make sure to match the polarity?

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Yeah, I went back in and checked the adapter harness I put together, everything looked good.  

I put in the Infinity speakers a long time ago...never had any problems with the stock head unit.  I'll try out one of those audio diagnosis CD's.  That would be funny if I'd had a speaker out of phase for years. 

Thanks for the suggestion!

Matt

defective wrote:

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Had the same problem with a Clarion, tried matching the Clarion harness guage, same issue, changed to a 10 gauge.... works great now.... I know a chain is only as strong as the waekest link but may have been the quality of the 14 guage wire.   just a thought.    BTW: The clarion was also in a boat.

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Wow, thanks for that tip! 

How many watts was your head unit?  And did you use 10ga just for power, or both power and ground?

Thanks,

Matt

Okay, I have gone to 10 gauge power and ground....still have the problem.

I used some test tones and determined that my speakers are wired in phase...Left/Right, at least.  I've got crossovers for the front speakers and none for the rear, would that cause any problems?

Also, I have in-line "bass blockers" (capacitors), could those cause a problem?

I took it to a local car stereo shop and had their guy listen to it, he was telling me he thought it was a problem related to the factory amp, and could be avoided by running new speaker wire directly from the head  unit to the speakers. 

I had the Delco "Premium" system, which, as far as I know, had one external amp that was only for the 6x9's.  Since I don't even use the 6x9's anymore, I disconnected the wire connector going to that amp.  For some reason, both front and rear wires are routed in and out of the amp.  However, after disconnecting the harness, my front and rear speakers still work.  So maybe that amp was wired in parallel with the speakers?  I guess I need to do some more investigation.

Any help is appreciated!

Matt

Okay, I busted out the shop manuals, and the schematic shows the factory amp is wired in parallel with the front and rear (4") speakers.  I guess it takes the low frequencies from these signals and sends them to the rear 6x9's.  I confirmed that with the amp disconnected, the 6x9 wiring in the rear gets no voltage.

So....I guess the only thing left to do is open up the door panels (ugghh) and run speaker wire directly to the speakers, and see if I've got bad speakers or a bad head unit.

When I faded the sound seperately to each speaker, the problem was still there.  And when the cutting out would occur, you could hear a popping in the speakers that were not being driven.  Does that tell us anything?

Thanks,

Matt