I just got the AUX input installed in my '06 530i and I am really disappointed with the sound quality. Its horrible; much worse than I would ever expect. I use an MP3 cd in my car and have the same files on my blackberry and iPod. Both the blackberry and iPod sound horrible through the AUX playing the same MP3 as the CD, where the CD sounds great. First change will be to get a new input cable, but when I used my existing cable on my friends car, it sounded fine. I am planning on removing the high pass filter from the vehicle, but could there be a problem with my install? The sound is nothing near what it should be, but before I do anything, I might have the dealer take a look.
On a second look and some light analysis of the filter, it will stay. It is a high pass filter, and will only filter out frequencies below about 5 hz, which is below hearing range. The ratio of output to input at 5 hz is still .916 and it drops off quickly from there. Thats not the issue, but does anyone have an idea about what could cause such poor sound from this system other than improper hookup?
If you want an idea of how it sounds, go to your iTunes equalizer, bottom out all of the ranges except 16K > +12 dB, and 32 > -6 dB
'06 530iA, iDrive/Nav
Dead: 92 325i
Dead: 97 528i