Polar Bear

I have noticed when I play certain CDs that the automatic volume control will activate when there is no reason to. For example, I will be driving at a constant slow speed with no change in road noise, tire noise, A/C fan noise, talking, etc., and the radio will increase and decrease in volume and it is very noticeable. Is there a software update to the COMAND or AGW that perhaps addresses this? It tends to happen more when an MP3 (higher quality bitrate) CD is played in the COMAND unit and not the CD-Changer.

W211 US model with COMAND and Navigation. Late 2004 software is in COMAND.

Thanks.

konigstiger

AVC is checkable through SDS. In addition, mention DTB P-B-82.62/387 SEPT04 – corrects poor sound in logic7 surround mode by updating the AGW software or replacing the AGW and P-B-82.60/382b AUG07 – updates COMAND headunit software using service disc (tool) w211589142200.

SEC1939

I did not know the W211 had auto volume control? If it does mine does not work or is not turned on. How does one turn this feature on? I have it in my BMW's & like it.

Polar Bear

It is typically enabled from the factory and I think it can be disabled/enabled through Star Diagnosis. Unfortunately there is not a way for the owner to change/check the settings.

The H/K system works off of ambient noise - I can actually whistle in my car for a few seconds and hear the volume increase, or especially open the sunroof. It is not very noticeable when it working as intended, but I have a case where (it seems like only on certain CDs) that it works in an unusual manner.

The H/K system seems to be overly sensitive to the volume in which a CD is recorded - if you play a CD (I have some MFSL CDs that are really bad) that are recorded at a lower volume, the "loudness" compensation (the curve at which the system attempts to compensate for the lack of hearing sensitivity at lower volumes for bass and treble) is way off. Even at moderate volume the system has no bass whatsoever because it is turned up to 85+% volume and reduces the bass output. Lower the volume slightly and it sounds great, but just is not loud.

The loaner ML350 I drove while my car was in service didn't have this cutoff point, or at least it wasn't nearly as noticeable.

Barry45RPM

Most of the time this AVC feature is not too obtrusive, unless you are sensitive or listening for it.