Hey guys, I just got the 4100nex installed and it is awesome so far.  I have a quick question though about the mute function.  My last unit I was able to toggle between mute or attenuate and I know many other head units are like this.  On this unit there is an option in the sound settings for Mute level and you can change between Mute, ATT, or off.  No matter what setting I use it always just full mutes it.  Reading the manual more I think this setting might just be for external devices that use the radios "mute" wire which does not apply in my case.  Does anyone know if this is the case?  If so I'm assuming there is no other way to have the volume attenuate instead of mute when the "mute" button is pressed?  Thanks.

I'm just guessing here, but perhaps ATT just sounds like a full mute because your starting volume wasn't that loud to begin with? How does it work if you're listening at a higher volume and then try to mute [attenuate] the volume? 

Thanks for the reply.  I thought the same thing but even at about 3/4 volume I can't hear anything when I hit the mute button with the setting set to "ATT".

Did you ever figure this out? I was wondering the same thing.  The way I read the manual, I interpreted it as I should be able to attenuate the sound, not just mute it completely.

I pretty certain it is only for external equipment connected to the AUDIO MUTE lead (its yellow with a black stripe on my 8000).