Did a booboo and need some help

[racer2086]

Its a 10 Channel Lear Amplifier non-HK. Found one on evay. Might take the plunge on it.
I am pretty sure this is what is wrong with the sound system.
Any other ideas?

What about the head unit? Check the tone controls? Maybe something reset, or blew out. I had a front left and rear right speaker problem in my car when I bought it. Tried a new trunk amp, but it was actually the radio that was bad. Can you swap for a known good radio to test?

[Oli77]

I tested everything in the head unit and it is looking like it can control output to the rear/ side/ bass/ treble. It sounds terrible as only the 4 high frequency speakers are active.

I assumed the lower frequency speakers were driven by the amp in the trunk (makes sense that the 4 high frequency speakers would work if they were driven by the head unit that does not have the power to drive the lower and mid frequencies in the doors).

I will test this hypothesis this weekend and will report back. I found a trunk amp for $55.

[Oli77]

Win!!!!!!!!!
That was the fix. All speakers are working again.

Hope this helps the future forum members who loose the sound to all but the high frequency speakers in the car. Those are driven by the head unit (which in my case was just fine), all the others (mids and low frequencies) are driven by the amp in the trunk.

Now on to try maybe do this fix:
https://www.bimmerfest.com/threads/e...5-mins.526646/