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iPod Aux Input Sound Quality

14K views 46 replies 16 participants last post by  Nick11110000 
#1 ·
I recently had issues with the sound quality for my radio and the local BMW dealership swapped out the head unit and gave me a "BMW Business CD" head unit. Everything sounds great: sirius sat, cd, fm radio BUT, the AUX input for iPod sounds horrible (all treble...NO base). I did not have this problem with my old head unit before it started acting up. Any idea?
 
#37 ·
The BMW Business CD in mine is Part # 65-12-9-124-633

No chrome around the volume knob,
no separate on/off amber light in the display,
and AUX works perfectly.

The music note button does not do anything specifically for AUX in mine,
unlike what madurodave was describing.

When in AUX, pushing it just brings up the usual speed sensitive volume, bass, treble, balance and fader for the head unit in general (all modes).

AFAIK the input level for AUX can only be altered at the music device itself.

Not sure if 2007+ models can do more, or what exactly can be done control-wise in the case of the (more expensive) iPod Adapter setup.
 
#40 ·
Not sure if 2007+ models can do more, or what exactly can be done control-wise in the case of the (more expensive) iPod Adapter setup.
The 2007's have a level you can set as well. I have mine at 5 to get good listening levels.

Then I had to adjust bass and treble to get some decent lows from the music.
 
#38 ·
Apparently, they got it figured out and I am picking it up later today. The BMW Engineers said there was a problem with the "capacitor" and the "ground" (or something like that.....sorry, i'm not very technical). It may have to do with what Evlengr said in an earlier reply. I'll update the language from work order once I receive it.
 
#42 ·
As previously stated, the most likely problem is that the ground connection on the plug is not grounded to the car. There are two ways to quickly tell. If you or a friend have an ohmmeter, check for resistance between the little metal ring on the aux plug and the metal ring on the cigarette lighter. If there is no continuity, that will confirm the problem. Also, if you have a 12 volt power plug for your Ipod, if you run the device off of it, that should ground the device and make the sound better although it may introduce ignition noise. If the sound changes, then either the cable is defective or the ground terminal is on the wrong block on the back of the CD player.
 
#43 · (Edited)
The sound is much better but, it is still not great. I have to mess with the bass/treble settings just like Madurodave says above.

Unfortunately, there wasn't that much detail on the work order. It basically says they replaced my AUX input jack and installed an "in line audio filter." There were no details about the capacitor and the ground connections. The part # is listed as: 82 11 0 149 390

2006 X3 -
Original Radio Head Unit part # = #65 12 9 189 963
New Radio Head Unit part # = #65 12 9 205 279
 
#45 ·
It basically says they replaced my AUX input jack and installed an "in line audio filter."
That filter greatly reduces the sound output from your AUX jack. Volume levels as well as bass are reduced.

I found my X3 sounds better than my wife's 530xi with my iphone plugged into the AUX jack. I am not sure if it is a different filter or just due to the head unit. The 530xi sounds a lot more muffled.
 
#44 ·
Jlas, sent you a pm. Something smells fishy.
 
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