konigstiger

DTB S-B-82.85/544a FEB09
ML as of MY06, SLK MY05-08, C MY05-07, CLK MY05-08, E MY04-08, CLS MY06-08, and R as of MY06 with iPod interface kit

iPod intermittently cannot be operated or controlled using steering wheel controls, delayed response on IC display, and/or iPod volume too low compared to other audio sources this may be due to incorrectly loaded MP3 files onto the iPod, the Aux level of the iPod is too low, or a CAN communication error between the head unit and the IC. To resolve, the iPod Interface Module should be replaced with part #B67824252 or later.

FYI if equipped with the latest iPod interface, you can adjust use this procedure to adjust the Aux volume output:
- Use the MFD buttons to select the iPod menu (Aux) in the IC
- Simultaneously hold down the down arrow + Tel hang-up MFS buttons for about 8 seconds the IC displays “DIAG”, “HW” -> wait another 5 seconds -> “DIAG” “Vol…”
- Within 5 seconds of the “DIAG”, “VOL” display appearing, pres the up or down arrow to adjust the Aux volume. Make sure it is set to the loudest -> wait 5 seconds without pressing any buttons -> the display will return to iPod main screen automatically.

pinebaron

You may additionally install an IPOD preamp, an item available from MB; it connects between IPOD and the original connector wire to Command. It is plug in with no splicing required.

tivoboy

Is this adjustment listed above the best way to up the volume on the AUX/ipod in? i have just been trying the ipod connector in the new C300, but indeed the volume is a bit low and always has to be adjusted up.

Polar Bear

I have had mixed results in the amplifier. At first, I could tell a big difference in sound quality (it was much better) however after listening to many more songs, I noticed it introduces distortion/clipping depending on the max level the song is recorded.

I have normalized my library to a lower level to attempt to compensate, but it still seems to clip, which will damage speakers.

I am curious if the COMAND is causing the clipping, or of it's the iPod interface itself.

pinebaron

iPod quality cannot be compared to CD quality however clipping or distortion can be minimized by reducing input as described in post #1. I rarely use it at full blast hence cannot comment on damage to speakers. In recent years, MB have reduced Bass pre-amp output in Command to protect speakers. I have considered installing aftermarket speakers but have not got around to the task yet.

Polar Bear

My particular iPod adapter is the older software version without that feature.

As for the distortion/clipping damaging speakers - you do not have to listen at a high volume for it to damage speakers. If they are receiving a distorted signal (even a low to moderate volume) the signal is not clean and therefore can promote speaker damage.

I think it would be difficult to replace the speakers if you have an H/K system due to impedance matching, etc.

pinebaron

An interesting article for your reading:
http://www.monstercable.com/mpc/stab...Some_Facts.pdf

Polar Bear

Hmm - according to Richard (a very nice guy in the Grand National community and he actually hosted a meeting at his garage recently) it would not damage the speakers if it is clipping before amplification.

Good read!

Polar Bear

That post actually makes me feel a whole lot better because now I won't be as concerned that it will cause speaker damage... that keeps me from listening to my iPod as much.

I always knew that a stronger amp would minimize speaker damage over a weaker one causing distortion, but this obviously only applies if the amplifier itself is causing the distortion.

pinebaron

I worked as an audio test engineer for a Japanese Mfg. for several years. I took the easy way out by sending you a link.

Polar Bear

Thanks for the good info - I worked in the auto sound industry for a while and apparently that is a fairly common misconception. Glad to get the right answer to that question!

Polar Bear

I wanted to add some info to those who may be following this thread - and for the sake of future searches...

I had the DTB performed and had the outdated iPod adapter replaced with a current version. The distortion I was experiencing disappeared. It appears that the old iPod adapter was being overdriven by the iPod, instead of the AUX input on the COMAND unit being overdriven by the iPod module/amp.

A few experiences support this idea that I performed *before* changing the module -

I re-encoded my music on my iPod to a higher dB (target 98dB) to compensate for the lower volume issue that many experience *without the in-line amp* and still experienced the distortion.

I then lowered the volume of the music on the iPod to a lower dB (target 89dB) and reinstalled the in-line amp. I experienced nearly the same volume as the method listed above, and still experienced the distortion.

After the new iPod module was installed as listed in the DTB, the in-line amp was actually still in the car, and there were no distortion even with the amp installed and the iPod module configured for VOL: +++ setting.

So... it sounds like the old iPod adapter clips at a lower volume/input level than the newer one.

mprsev

Thanks for the follow up post. How can I determine which version iPod adaptor I currently have? I am running the $0.05 in-line amplifier and the sound definitely distorts now even with my iPod at half 50% volume, Flat EQ and Sound Check On, and iPod module configured for VOL: --- setting.

Polar Bear

To get the hardware and software version:

With the key on and the iPod playing and the menu displayed in the I/C press the ↓ button on the steering wheel, with the Telephone Hang-Up button at the exact same time (the post above states the ↑ button, but this did not seem to work on mine for some reason). Hold it for about 7-10 seconds and the display will display the hardware information and software version. Mine displayed HW2006 E41 and SW1706 100. This is before the VOL:--- is displayed.

With the updated iPod integration unit, the in-line amp is not needed (nor recommended from what I have read). Also, I haven't seen where the volume on the iPod actually makes a difference as I think it uses a "line-out" function on the iPod. I use an application called iVolume to normalize the iTunes library, and turn Sound Check on on the iPod and disable the EQ and get pretty good results now.

Polar Bear

If you would be interested in trying a test track, send me a PM and I will provide a download link. The track in question always distorted on my previous iPod module, but no longer does on the new one. It is a track from the Robert Plant and Alison Krauss CD Raising Sand.

I now get zero distortion with the new model - at least with the tracks I have played so far - so it was apparently the iPod module the entire time, and not the AUX input on the COMAND.

mprsev

Thanks Polar Bear! I checked and my dash displays HW2006 E41 and SW1706 100 as well so I guess I have the latest? So I guess I need to remove the inline amplifier.

Polar Bear

I would try that and see what it does.

I am enjoying my iPod 200% more than I used to with the old module!

Dtv211

Maybe this is a dumb question, but does this apply to ipods only, or for all audio aux inputs? I tried to play my 300 mb Paul Van Dyke mix on a blackberry storm today, and it sounded really low, bummer

t-bone

Was it free to have the module replaced?

hercules

I have all the symptoms that you describe above with an ipod iterface I purchased on Ebay, I can not remenber What part number is , but lately I have puschased at a good price a new interface B6 7824252 from a dealer in Germany and for lack of time I have not had the opportunity to fit it yet .

Do you think this should solve all the problems you decribe.

By the way it is for a W164

konigstiger

It should this is why MB released bulletin to address symptoms listed -- ML (164.175/186/871) as of '06