Radio issues, '90 Vert. front door speakers poor sound.

Ok, time to ask for help. On my ’90 Reatta vert., I am having issues with my factory radio system.

The sound from both front speakers is low in volume and ‘tinny’ with the tone equalization controls set in their midpoints. In this configuration the two rear speakers sound about right.

Here’s what I’ve done:

1) Replaced the six caps in the power module with new caps—no change

2) Replaced the power module with a used module believed to be good—no change

3) Tested new speakers, Pyle combo. 5.25” and coaxial tweeter—no change (I did not leave the Pyles in as I’m not sure the Pyle’s will fit with the door panel—they look like they would, but the tweeter does stick out just a little past the frame, so as I noticed no change I kept the original speakers). Sound does come from both the 5.25" and the tweeter.

4) While there, I disconnected the factory tweeter and it’s crossover circuit to be sure it wasn’t causing the problem—it wasn’t.

5) Replaced the complete radio with a ‘believed to be good one’-no change.

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If I set the equalization controls at about ¾ up, the fronts sound almost OK, but then the rears are ‘boomy’.

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If you have a convertible, can you see how yours sound with the fader set to 'full front' and the tone equalization set to their midpoints? Nice sound or tinny?

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I’m an engineer and love a challenge, but this one has me stumped.

Thanks in advance,

Tom

I'm wondering if one or more of the speakers could be wired out of phase (reversed polarity). It should be correct from the factory but you never know. Speakers wired out of phase can have a significant impact to the mid and lower frequencies.

I'm wondering if one or more of the speakers could be wired out of phase (reversed polarity). It should be correct from the factory but you never know. Speakers wired out of phase can have a significant impact to the mid and lower frequencies.

I suspect not, the sound is low and tinny with the tone equilization centered and the fader is set to full front and the balance to either full LH or RH speaker, so that only one speaker is on.

As information I have used a place called Speaker Exchange in Tampa Fl. for both my 1989 and 1999 Riviera. Recently they rebuilt the 1999 door speaker for $40.00 plus shipping phone 813-237-4800. Just in case someone needs it.