Audio Problems

[DR]

With a 1993 Explorer with stock JBL sytem all speakers make a popping noise when using the multi function volume -/+ switches in any mode. As far as I can tell this system only has one speaker in each door. At low volume there is static and no audio. There is some distortion in the front speakers. Turning the bass down all the way helps. With the receiver out and on the bench hooked directly to small speakers the volume is low as expected but all problems show up so this tells me the amp is okay. Feeding audio directly into each amp input one at a time seems to sound okay using a small tape play back unit as a test input. This tells me the amp is okay. So I buy a receiver off of ebay and it does the same thing. Has anyone got an input to what is the problem. Is there a source for an electronic schematic on these units that will not cost more than the unit is worth. Along with a schematic and someone telling me what the problem is I should be able to fix any problem.

Thanks for any help,
Don

02 19 2007 Problem Fixed

Thanks for some good input I now have a good working unit. Both the HU and all four speakers were bad. I replaced the HU and speakers to fix the problem. By taking a close look at the speakers found the cone was not connect/or broken at the outer frame. With the factory speakers having a built on grill one has to look real close to see the deterioration that has taken place over time. So if you have original stock speakers and distortion take a close look at the speakers to see if they are any good.

Thanks for some good help,
Don

 

[Crizz]

Put a 1.8 k-ohms resistor in the remote-line between HU and Amp, then the pop will stop. The problem is the Ford-stock amplifier, it needs 8 V switching / remote-voltage. Aftermarket HU´s give a 12 V / 13.8 V remote out, the Ford-amp gives that pop to the speakers.

Reason for that : Ford gives a clipping signal back to the HU on the remote wire, only supported by factory HU´s. That´s why they running 8 V remote-voltage.

A little 1/4 W resistor with 1.8 k-ohms fits to remedy the problem.

 

[DR]

I'll have to think about what you are telling me. It could be I have more than one problem, but the fact is the system I have is all stock. I think it is getting worse with time. Could the problem be the amp and my test methods are not good enough for me to beleive that is the problem? When I put the HU on the bench with the basic hookup and the problem still took place that points to the HU to me. I'm thinking this is a basic problem of the system so others would be having the same sort of problems. So I'll do some thinking on this and go from there. Thanks.

 

[Crizz]

Well, if it´s all stock than i guess it´s the HU - esp. when it does the same on the bench.