I pulled out my trusty old sound meter and did sound measurements while my wife drove. I left the AC on which was at quite low fan speed. With ANC microphone blocked with my finger (ANC defeated) the sound level was 68dBA.
In normal mode (ANC functioning) the sound level was 62dBA. This was at just over 50 MPH on an asphalt rural road, which while not bumpy has a fairly worn and rough surface.

For those of you that aren't familiar with logrithmic scales this is much bigger sound level drop than it first appears. Every 3 db is double the sound level so the ANC appears to have cut the ambient sound by 75% (4x). To me that's a very big deal! I'm guessing that has to equal several 100 pounds of sound deadening. Also sound deadening material never is tuned quite right. While it may do well on some frequencies it doesn't do that well on resonant frequencies all cars have. An active sytem can account for this and be good across the whole low frequency spectrum.
To me, a real step ahead.

 

wow. thanks for the info. that is impressive!

 

Rich,

Am I correct in assuming the ANC is always turned
"on" in the car or is there a special button I need to push?

 

always on . . .

 

 

It is always on. Just hold your finger over the little hole just back of the sunroof control to hear the contrast.

 

rich - great post!

btw, where is the mic for anc?

mark

 

above your head, where the onstar/homelink/sunroof buttons are. there are two mics, one for the ANC and one for the HFL/onstar. I don't know which one is which though...

 

I tried this today. There really is a noticeable difference when you cover the mic up!

Try this.. cover the mic with your finger and gently accelerate, you'll immediately notice the tone of your exhaust has become lower and louder! It practically vibrates the entire car at certain rpms! Uncover the mic and all of a sudden, all is quiet again!

wow!

Oh, and for you folks who dont know where the mic is located, it's right between the moonroof and the headrest/rear shade/dome light stack. It's a small square with a little hole in it.

 

Is the ANC different than Audio Pilot?? Reason I ask is everyone is saying the ANC is always on. The Audio Pilot can be turned on and off where the bass, treble etc is found

 

ANC and Audio Pilot are two totally different things. We have yet to figure out a way to disable ANC besides covering the mic.

 

Have had the RL for 7 months and I'm still finding new stuff. Will have to get out the owners manual and check out the ANC thingy. How does it work? I just found out about the touch sensor on the trunk latch last month when a friend of mine opened it. I have been pushing the button on the door or fumbling for the remote.
This site is so cool

 

I tried it tonight. It was amazing the difference, especially when accerlerating. I guess it isn't a gimmick.

 

I don't think that it is this site is so cool, although I think that it is, I think that it is this site that allows people not to have to read the manual.