Alpha1220

I have this posted in the 200/5000/V8, but I thought it might get more attention/responses here. To anyone seeing this again, sorry about the double post.

Here goes:

The car is a 91' 200 20v sedan, 105k

Problem 1: Back in 02', after having driven the car for about 5-6 months, I noticed that the volume of the sound coming out of the left driver door had become MUCH lower than the volume of sound from all the other speakers. For any given level of volume, the left front would be lower. But it wasn't out completely (you could tell by putting your ear to the door at normal volume levels). Volume would still rise and fall with adjustment from the radio panel, but, always a proportionately lower level.

Now, I may tend to ... play the volume of my radio/CD at slightly higher levels than advisable. So, my first inclination was 'oh no, I damaged the speaker'. However, to my suprise, I brought it into the dealership, and they said that the problem was just a balance issue, and that they had adjusted the balance on the front speakers through some internal control or something of that sort (since obviously, there is only a rear/front balance on the actual radio panel).

I didn't question a good result at the time. However, sometime in 2003 (so, in a matter of months) the exact same problem reappeared - VERY low proportionate level of volume in the left front speaker compared to the rest of the system. How should I proceed on this? Is it just a balance issue? Can I adjust this? Why did it reoccur?

Problem 2: Fall of 04 this issue cropped up. When listening to the radio or to a tape (I use a CD player with a tape-convertor) you hear a distinct buzzing noise. Very odd behavior: it is always there when I turn on the system. Many times, after listening to the radio for a few minutes (30, let's say) the buzzing will go away, but not always. If it does go away, it sometimes returns during the same driving session. In short, behavior is very random. One thing I noticed is that the volume of the buzzing does not raise/lower in proportion to the system. If you play the system very low, the buzzing is very evident. If you raise the volume enough (not a very good solution, I know) then you aren't able to 'hear' it above the music, but it is still 'there.'

Again, not sure really where to even begin with this problem.

Any comments / advice are greatly appreciated. If I can be useful and give any more detail / answer any questions, please just ask!

A sad audiophile

P.S. I did have the replacement work done on the system following the recall for the fire issue. I was the first one at the dealership to have it done, which meant I was the first one at the dealership to have them not properly fix it and make my whole system not work. However, they fixed whatever they had done the 2nd time around. That is the only history of repair work I've had on the Bose system, other than the supposed balance adjustment that I mentioned above.

MacSub

Some systems are tuned to give less power at the drivers side to give the driver proper stereo imaging. Does the rear left suffer the same problem.
As regards the buzzing, is this alternator whine (does it rise & fall with revs)?
Does it still happen with the tape adapter taken out/disconnected?

Alpha1220

First off, thanks for responding.

The buzzing sound is constant in tone and volume, and doesn't rise or fall really. (Like I said in the first post, you can drown it out by raising the volume high enough) It's the same with the tape in or out. It's a werid sound. Not a whine -- I almost want to say that it has a staticy element combined with the buzzing sound.

In terms of the volume difference: To my memory (I haven't been home to drive in several months), the rear left isn't having that problem. However, I'm going to have to check it out once I head home (I'm in the UK for another 2 weeks) because I never bothered really sitting in the back of the car.

The volume difference, at least in my judgement, is VERY noticable. As in, enough to loose the sense of stero when you're driving the car. It's not just a '5' vs. a '9' in terms of difference: it's a '1.5' vs. a '9'

One of my big concerns is that, from another site, I've been told about the possibility of their being a l/r balance adjustment, even though the panel only has a rear/front fader. supposedly, you pull out the volume button and twist it L/R to adjust balance.

However, my concern is that, if the left rear is fine, then what I'm really dealing with isn't a balance issue at all. I'll just end up adjusting the front and ending up with the distribution in the back being like 80/20. I'm worried that something is fundamentally wrong with the left front spkr.

Again, I'll have to give a close listen when I get home.

Any advice you have is appreciated.

MacSub

You need to identify if the 2 problems are linked, then identify if it is the speaker wiring, amp or HU.
If the buzz is just from the left front then a quick look at the speaker will hopefully verify whether it is a dodgy connection, it could be a dry solder joint on a system 14 years old, either at the speaker or amp. If the wiring to from amp to speaker is OK then it could be the pre-out wiring to the amp. If it was me, I would dig out the amp and run a soldering iron (with a bit of new solder) over the solder side of all the wiring joints, just to heat up the joints and rectify any dry joint issues. Make sure the system is off before doing this.
It is far more likely to be wiring/solder problem rather than a component fault, but could be hard to identify. The HU could also be the culprit, the pre-outs have been known to "go fuzzy" but this usually effects the sound quality rather than just the volume.