Auto volume control: As you go faster, the volume turns itself up. If it's on low, it turns it up a little, med is more, etc. Since my ears ring all the time, I have mine on high. Some owners complain that their avc doesn't work; mine works fine.
Right about that Dr. Phil, mine never did work. I have a question about it though. As the AVC increases the volume, do you see the numbers go up on the digital display as you would if you were increasing the volume manually?
I always have mine on high. I notice the volume increasing when you get to about 60mph. When you drop below 60, the volume goes back down to where it was before. As was said above, it only works with speakers, & not headsets.
Well I hate to disagree, but mine definitely works with the both the speakers or the headsets. I just checked this out the other day while running 70mph down the highway. I agree the change is very subtle, but having the AVC on HI makes a difference with the headsets on.