# VW EOS factory installed iPod docking station with video iPod 5.5G



## rozum (Jan 31, 2008)

Hello All,

This thread is a summary of what I did along with what I feel will correct the problem (something to which I am about to do).
Recently, I purchased a Volkswagen EOS that came with the factory installed docking station. The controls to the iPod works as expected via the radio, but unfortunately, the quality of the audio playback had background noise "buzzing / hissing" that would come and go. This noise is loud enough to be really really annoying and unnerving in quite music passages.
First the symptoms
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If the iPod wakes up out of "hibernation" mode (Video iPod is turned off less than 14 hours) there is a background "buzzing / hissing" sound during audio playback...but not all the time. If one skips to the next song, the noise for the first 1-2 seconds sounds like cross talk between the audio lines and the hard drive spinning up. If one skips to the previous song, the first 3 seconds (exactly 3 seconds) is crystal clear with no noise. After 3 seconds the noise it comes back.
If I reset the the Video iPod or have the car turned off from more than 14 hours (i.e., overnight), then there is no noise.
Attempt to solve the problem via Apple and VW
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First let me say that support from both Apple and VW on this subject was sad considering that both products are new. 
VW did check the cables and docking station, and informed me that the problem was with the iPod since everything "looked" like was in working order. 
After going through 2 levels of support with Apple they replaced the iPod, but the replacement also had the same problem. I did borrow an iPod classic into the docking station with no problems what so ever. In other words, the problems followed Video iPod 5.5G. Apple informed me that the problem is with the VW docking station and since it isn't a certified apply product, there is not much more they can do. 
I did explain to both support parties that I have doesn't work and both parties stated it was the other party's problem. 
Observations and What I Believe is Wrong
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Thinking that maybe the problem was with my ripping of my music, I examined my mp3s it and found that maximum volume was around 91dB (normal is 89dB). In other words, they were ripped correctly.
I did noticed that when if I switched between playing the iPod audio to an FM or CD source the volume of the sound increased dramatically (approximately 10dB!!!). 
In my opinion, what was occurring is that he pre-amp signal of the iPod audio was being send directly to the line-in of the stereo system. In addition, I believe that the pre-amp circuitry for the Video iPod doesn't have as much drive capability compared to the previous iPods. Either ways, noise is being introduced on the audio line that is being amplified by stereo system.
Note: I feel that this whole problem could have been averted if the VW's docking station had a pre-amp installed in it.
Solution: Software
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This first and more easy solution was to increase the gain of my audio files. I used the program MP3Gain (http://mp3gain.sourceforge.net/). This enabled me to increase the gain (by 10dB)and keep the current dynamic volume. This worked as expected, for I no longer heard the noise, but the high volume sounds became distorted. This distortion was significant that it was difficult to listen to the music.
I next compressed the music, prior to amplifying. The music wasn't distorted, but it was always at the same volume (no dynamic range). 
Potential Hardware Solution
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While it is clearly evident that the docking station that came with the car has "issues," I don't necessarily wish to purchase a new $150.00 solution. So what I am planning on doing instead is installing a pre-amp on the line-out signals just as they leave the iPod. The product Pie Ld1 2-Channel Adjustable Line Driver (http://www.discountcarstereo.c...D=317) looks like it will do the trick.
Questions
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1) While this solution looks like it will work, has anyone tried it?
2) Is there another option that could solve my problem that I haven't found?
3) Has anyone else experienced this? 
Note: I have read one thread topic in other forum someone stating a similar problem, but the date was 2006.
Thank you ahead of time for your advice and assistance.
-- Stephen


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