After market spells distortion!!

[Higgs]

What's the story with the wiring on my 89 325is? The factory player died, I installed an old Sony XR C210 cassette stereo (25watts) and I am getting distortion and cutoffs.

Any help would be great.

[BlazeMan]

to the head unit?

Are factory wires going to some hidden BMW amp/crossover in the trunk that could be causing this prob?