Hi,

I've tried searching through the forum and haven't found the answer so I wanted to start a new post.

I have a 2008 535i with built-in iPod/Aux port inside the center armrest compartment. I have been extremely disappointed in the Aux In sound quality when using my iPod and wanted to get inside to see if the famous resistor/capacitor protection circuit is embedded in the wiring so I could remove/bypass them. It has been well documented by a few folks that removing the resistor/cap on the Aux input on older E60 models improved the Aux In SQ...however the Aux port was in more accessible locations to remove.

It looks like I would somehow need to go through the center compartment removal procedures to get to removing the USB/Aux port module and looking at the internal cable. Can somebody shed some light on if there is a simpler way or it's got to be all the way? thanks.

Alan

 

Anybody tried this yet? Thanks.

 

Just to clarify, are you connecting the iPod through the Aux Input only? Not using the BMW supplied "Y" cable that connects to both the USB and Aux Input?

My sound quality is just fine using the BMW cable though once I had the signal dropping in and out and the dealer changed the connector and it's been fine since. The service guy popped it out but as I recall the USB and Aux Input are a single unit. Agreed, it is an tough spot to reach...

 

I am using the BMW supplied iPod Y-cable which has 1/8 miniplug and USB. The sound still goes through the analog portion of the Y-cable and I want to make sure there isn't the resistor/cap circuit limiting the sound. Uncompressed audio playing through iPod line or headphone output into the AUX/USB input inside the center console loses "life" compared to a CD playing through the head unit. The iPod is not audiophile quality, but it isn't crappy either. There just seems to be some filtering going through the AUX port.

...in process of removing the armrest to take a look.

 

I went ahead to partially disassemble the armrest console using guidance from some other posts here on the 5series.net forum where I was able to reach under the console assembly and push the AUX/USB module out into the armrest compartment.

I have attached pictures where I disassembled the aux connector to find a small PCB with two capacitors. One cap was connected between right channel signal and GND. The other cap was connected between left channel signal and GND. There were no resistors on this board like the other AUX port kits for older cars. I removed the caps from the PCB and reassembled the module and center console. Guess what... the sound from my iPod is no longer muffled!!!

The caps measured 100nF (0.1uF), so these caps acted as a low pass filter and I could definitely hear its effects.

If you spend a lot of time listening to music via iPod or other player through the AUXIN port, the modification is worth the effort to getting sound quality similar to what comes off the head unit CD player on the E60. I actually compared four combinations:

Stock BMW speakers + original AUX - bright/lean midrange
Stock BMW speakers + caps removed - brighter midrange with more high frequency
BSW Stage 1 + original AUX - iPod sounds restrained/muffled
BSW Stage 1 + caps removed - this makes the iPod sound the best to be more comparable to built-in CD player

 

Pictures attached...

 

Nice job! I always thought there was a little high end attenuation on my Ipod thru my '08 535. Thanks for posting.

 

How did you remove the armrest console ?

 

I have upgraded the system in my 08 535i with a JBL MS8 and find the sound of my ipod direct into the MS8 much better than thru the BMW aux. There's a lot more going on in the MS8 thru the BMW aux but would be nice if this fixed it. I hear the same kind of differences you do. How did you remove the caps? Doesn't look like you can bypass the whole board like on earlier models.

 

I have a USB flash drive as my source for music on my 08 528i....I can definitely hear some "noise" compared to when I had my old car (which had a nice aftermarket sound system). Does this also improve usb audio quality?