[KANWAR]

driving around last night, i looked up at the map lights and noticed something i hadn't seen before. i have a 1LT, and right behind the driver side map light is some sort of vent? There is a matching one next to it, behind the passenger map light, but it doesn't have 'slots' in it, it is solid. The one behind the drivers map light has slots, and is black behind the slots. At first i thought it was the mic for the blu tooth, but that is right above my head, in a round little speaker. Haven't had the chance to take a picture yet, so hoping this description is enough.[/color]

 

[cottonseed]

Thats the vent where onstar releases the nerve gas when your car has been reported stolen ;D I never noticed that I dont think I will have to take a look at it when I get back into the car

 

[KANWAR]

Thats the vent where onstar releases the nerve gas when your car has been reported stolen ;D I never noticed that I dont think I will have to take a look at it when I get back into the car

Nerve gas, now it makes sense. thanks! LOL! ;D

 

[Phantm006]

It's a microphone. I believe it's for the onstar and Bluetooth. The little circle above your head is for the ANC. There's also one over the rear passenger seat. I could be wrong on use, but it's a microphone.

 

[KANWAR]

It's a microphone. I believe it's for the onstar and Bluetooth. The little circle above your head is for the ANC. There's also one over the rear passenger seat. I could be wrong on use, but it's a microphone.

ok, dumb ? for you, what does ANC stand for. i don't remember there being anything above the passenger seat, will have to check. all i remember is the round little speaker/mic above drivers head on the ceiling.

 

[mnussbaum]

Interesting thread, I was wondering the same thing. ANC=active noise cancellation. There's a large speaker in the right rear cargo area that pumps out sound to cancel road noise. I had seen the small round thing over your head but didn't know what it was for. Now I would guess it's the microphone input to the system. Very cool!!

 

[INNOCNT]

It's a microphone. I believe it's for the onstar and Bluetooth. The little circle above your head is for the ANC. There's also one over the rear passenger seat. I could be wrong on use, but it's a microphone.

It is the microphone, but I don't have any other fixtures above the drivers head area or anywhere else in the headliner?
Possibly a Canadian model change?

I do have 8 other noise cancelling speakers mounted elsewhere! ;D

 

[rbarrios]

on other GM's there will be little vents around the car- that sample the temp inside the car. for the cars that have the multi zone AC system- (digital system). it samples and regulates temps accordingly.
the lower trim models have no use for the vents.

thats another explanation for such little vents.

 

[INNOCNT]

on other GM's there will be little vents around the car- that sample the temp inside the car. for the cars that have the multi zone AC system- (digital system). it samples and regulates temps accordingly.
the lower trim models have no use for the vents.

thats another explanation for such little vents.

True that, but the Terrain's don't have the dual climate control option, so I'm still curious as to why some vehicles have these 'vents/speakers' above in the headliner?? as posted above.

 

[Phantm006]

Well I have 2 Round mics. One over the drivers head. And one midway over the rear passenger seats. May be a little further back. But when I bought mine that's what the dealer told me it was. And I just looked at gmparts direct. It has the little vent/mic/nerve gas dispenser listed as a microphone.

 

[KANWAR]

Well I have 2 Round mics. One over the drivers head. And one midway over the rear passenger seats. May be a little further back. But when I bought mine that's what the dealer told me it was. And I just looked at gmparts direct. It has the little vent/mic/nerve gas dispenser listed as a microphone.

hmmm, well i guess there are two mic's then. i am going to call my wife when i am in the NOX tonite, and put my hand over each mic, and ask her if i sound muffled. want to know the difference. Maybe then one if for phone, and one for onstar?

 

[Phantm006]

hmmm, well i guess there are two mic's then. i am going to call my wife when i am in the NOX tonite, and put my hand over each mic, and ask her if i sound muffled. want to know the difference. Maybe then one if for phone, and one for onstar?

Could be. Or for ANC. Let us know how it goes.

 

[INNOCNT]

Well I have 2 Round mics. One over the drivers head. And one midway over the rear passenger seats. May be a little further back. But when I bought mine that's what the dealer told me it was. And I just looked at gmparts direct. It has the little vent/mic/nerve gas dispenser listed as a microphone.

Well that's interesting to know, must be a US standard, my MY10 Terrain didn't have these vent/mic either.

 

[Phantm006]

Well that's interesting to know, must be a US standard, my MY10 Terrain didn't have these vent/mic either.

Really. Thats weird. I have a '10. But I know they don't come on there if you have a v6. That could be why. I'll take pis in a little while.

 

[INNOCNT]

Really. Thats weird. I have a '10. But I know they don't come on there if you have a v6. That could be why. I'll take pis in a little while.

Well... this is really f#@* up, yes, pictures please.
Have no idea why GM would exclude this for the V6 models, how would that have any bearing on microphone usage or bluetooth or other??

Perhaps we should have William Shatner's Weird or What get on this!! lol

 

[Phantm006]

Well... this is really f#@* up, yes, pictures please.
Have no idea why GM would exclude this for the V6 models, how would that have any bearing on microphone usage or bluetooth or other??

Perhaps we should have William Shatner's Weird or What get on this!! lol

Well the V6's don't have them because they don't have ANC. So there's no need for the mics.

 

[INNOCNT]

Well the V6's don't have them because they don't have ANC. So there's no need for the mics.

So I4 models have more road noise than the V6 models that they require ANC?
GM built the V6 models with better sound dampening materials? Such as bodyframe foam filler and thicker carpet/underlay?

Just seems odd IMO.

 

[Phantm006]

So I4 models have more road noise than the V6 models that they require ANC?
GM built the V6 models with better sound dampening materials? Such as bodyframe foam filler and thicker carpet/underlay?

Just seems odd IMO.

No. It's because of harmonic distortion. Read here:http://www.2010gmcterrain.net/2010-gmc-terrain-quietness.html

 

[GARYD]

If the 6 doesn't have it and the 4 does, it has to be the ANC doesn't it?

I do like the nerve gas answer better.

 

[Phantm006]

To help quiet the four cylinder Terrain, GM has fitted the vehicle with new Active Noise Cancellation (ANC) system, which uses a microphones to detect booming sounds inside the vehicle, and sends counteracting sound waves through the audio system speakers. A more powerful 264 hp 3.0-liter V6 is estimated to bring 18 mpg city and 25 mpg highway and does not use the ANC technology.