I know there has been alot of discussion about this on this board but I figured I would post my findings. I have just purchased an new 2007 525I I had a 2005 525I previously. I was so excited to pick up the car yesterday and if you can believe it the AUX input was one of the reasons. However I was affraid that I wasnt going to be able to enjoy it untill I removed the Cap. So here is what I found. I have been using a product for my ipod for years called a pocket dock from sendstation. It allows me to have a fixed low level output from my ipod it plugs into the bottom of the ipod and doesn't use the headphone jack. This product has worked great for all applications in my boat and when I am at home on my home theather. I know some people have complained of lack of bass so here is what i used for my test. I took multiple CD's from different genres of music I ripped them to MP3's at a fairly High rate 256kbps I then burnt them to a data disk and copied them to my ipod. I brought my ipod to the car I turned the volume up on the car to just above 1/2 and i played all 3 versions. It was very tough to tell any difference at all including heavy bass track songs. As a matter of fact when you did a blind comparision the AUX input sounded a little bit better maybe because you couldn't hear the CD spinning. Now i know this is just my opinion but the next thing that I am going to do is get a sound meter and a test cd that goes thru the entire spectrum and see if there is a volume difference. That will take a couple of days. The other thing i did notice was that if i hooked my cable up to my head phone jack on the ipod it did sound slightly different and definately not as good. That is just my own 2 cents once i get my sound meter I will be able to prove if it is infact louder or softer then the actual CD across the entire range. Obviously you are going to loss some quality going to MP3 but it shouldn't be enough to notice especially in a car.

 

I have done A/B testing between on an MP3 file burned onto a CD being played throught the in-dash player, and my i-pod connected to the auxillary input via the line level output. Listening to the same song, there is a very noticable difference in bass levels, with the auxillary input just lacking.

I have yet to do the capictor removal, but someday when I get the time I will attempt it.

 

OK, since I'm a NEW convert to the "CHIP" cap/resistor removal, and though I've done this the quality doesn't reach the level of the actual CD. But that's expected as you know because of the conversion to MP3. It doesn't matter what bit rate you use, there's gonna be loss in level and clarity. The question really is, How does the Sendsation piece work? What's the connection from the bottom..............? 1/8in connect? You mentioned it was LOW LEVEL. That means the output is not as hot as the headphone preamp out....correct? Please elaborate on the Dock piece a bit more, and a link also, oh and picture please.

 

I know some people have noticed a difference (using Line Level) maybe my ears aren't as good but I couldnt tell the difference using 3 different CD's. The true test is to use a sound meter to see if there is a noticable difference on the meter. Here is the link to the sendstation piece but the only proper way to hook it up to the aux in is via a line level input which this is. http://www.sendstation.com/us/products/poc...ineout-usb.html

 

Try setting your iPod's EQ setting to R&B... I have found this to be the best sounding