Driver's door speaker distortion

[beyonce_boy]

Hi all. I noticed that I posted this question in the "general E46 area" so I'm posting it here in Audio & Electronics as no one has responded yet...

My problem is with my 2002 325i with the Harmon Kardon stereo. When I bought the car, the stereo was awesome. As the car aged, though, the driver's door started to sound less crisp than the front passenger door -- most noticeably with the high-end sounds. As the problem progressed, the driver's door started sounding more muddy than the passenger door. I took it to the dealer, but trying to explain that the sound was more muddy to a BMW repairman proved to be a fruitless effort; they couldn't tell a difference.

The next stage of this problem came when the mid-bass (the bottom speaker) started distorting at high volume. The speaker was replaced, and this solved the distortion problem temporarily. The speaker started distorting again, and was again replaced. Recently, I hit a speedbump while shutting off the stereo and broke the volume knob. The dealer replaced the head unit (which is cool, as my car was produced 01/02 and before this replacement wasn't capable of Bluetooth, Sirrus, iPod, etc.) and the problem persisted. They then replaced the amp in the trunk. Still there.

Last week they had the factory rep look at it and the mid-bass was replaced again, along with the tweeter (the one up by the outside mirror that says Harmon-Kardon on it).

With everything they do, the problem is temporarily fixed, but now (four days later) it's worse than it's ever been. When you go from right to left with the balance, it sounds like a completely different stereo and the mid-bass is distorting again. My problem is, aside from the wiring harnass(es) there is nothing left to replace and the factory rep told me that very specificly.

Has anyone else had this problem? Any insight as to what could be the problem and what can fix this?

[El Presidente]

I've never heard of anything like this. Usually replacing the amp would eliminate any problem not solved by everything else. The only thing I can think of that is left they haven't changed are the crossovers. In the e36, they are part of the amp though, so I'm really stumped.

[beyonce_boy]

I mentioned crossovers to them as well, but they said that there's none in the car. Looking at the amount of wires coming out of the (tiny little) amp, the E46 is probably the same as the E36.

One thing I didn't mention is that it sounds fine for about the first 5 minutes, then gets worse after that length of time. Also, it's especially noticable when you get up to freeway speed and the equalization/volume changes.

Do you think it's possible that I have a bad wiring harnass in the door?

[jllphan]

You can rest assured it's not the midbass speaker, tweeter, or head unit. These have been replaced and the problem persists. It could be the wiring but the chances of that are VERY slim. From the get go, I would have said it is the amp. The amp has a built in crossover network, and either the crossover or amp itself are the likely culprit.

The aforementioned advice is predicated on the fact that the e36 and e46 share similar audio components.

Sorry your having all this trouble, it's nice to know your dealer is actually doin what they can....

[El Presidente]

but since he already replaced the amp, is is possible the one he got had the exact same defect?

[beyonce_boy]

it wouldn't seem likely, not in the exact same door in the exact same way, anyway... maybe it's just something i'll have to live with? that sucks...

[jllphan]

Whoops, didn't catch that part.

The only thing I could think of would be to closely examine the troubled door/speakers. Is it possible that rain water could be seeping down and destroying the components?

Other than that, by process of illimination (or in this case process of replacement)it would have to be that the wiring is exposed at some point between that particular channel's output and the speaker.