Added sub/ANC making a lot of noise!

[Rush]

As the title states, I added a subwoofer... I tapped the Blue/Gray and Gray/Black subwoofer wires for my line out. One problem: The Active Noise Cancelling apparently uses the sub in some fashion--Long story short, I'm getting a lot of feedback in my sub while driving. I essentially can't even use the box. Anyone have info on disabling the ANC, or working around it while maintain sub functionality? Thanks!

 

[zolt11]

I remember seeing an option under settings that turns bose ANC on and off? Maybe check there if you havent already?

 

[Rush]

I remember seeing an option under settings that turns bose ANC on and off? Maybe check there if you havent already?

Didn't see an option to turn off the ANC... There is one to disable the Bose Audiopilot.

 

[Anon2015]

There is currently no menu item or setting to turn off ANC. Over at the GMT forum there is a post on degrading ANC by covering the microphones.

 

[Anon2015]

As the title states, I added a subwoofer... I tapped the Blue/Gray and Gray/Black subwoofer wires for my line out. One problem: The Active Noise Cancelling apparently uses the sub in some fashion--Long story short, I'm getting a lot of feedback in my sub while driving. I essentially can't even use the box. Anyone have info on disabling the ANC, or working around it while maintain sub functionality? Thanks!

You've pretty much screwed the pooch. Over on GM-T, there's post with some detail about ANC and vehicles. When the ANC system was designed for your vehicle, BOSE/GM knew exactly where the subwoofer would be located, the subwoofer's exact FR curve, voltage to output data, etc. BOSE/GM also knew where the seats were located. By adding that second sub, you have moved the sub's location, you have changed the output and delay which simply means the basic criteria required for ANC to work (exactly 180 degrees out of phase and exactly the same volume (SPL)) is completely broken. What it amounts to is if you want BOOM, visit the range.

 

[Rush]

You've pretty much screwed the pooch. Over on GM-T, there's post with some detail about ANC and vehicles. When the ANC system was designed for your vehicle, BOSE/GM knew exactly where the subwoofer would be located, the subwoofer's exact FR curve, voltage to output data, etc. BOSE/GM also knew where the seats were located. By adding that second sub, you have moved the sub's location, you have changed the output and delay which simply means the basic criteria required for ANC to work (exactly 180 degrees out of phase and exactly the same volume (SPL)) is completely broken. What it amounts to is if you want BOOM, visit the range.

I think I've figured it out... took to the back on a troubleshooting adventure in an effort to disable the ANC. I unplugged the first connector (pictured below) to see what/if any impacts it would have. It apparently controls seat vibration/Rear camera functions/door chime notification/and YES, the ANC (And maybe a few other features???). So I started by connecting/disconnecting the wires one by one & driving w/ the bass knob cranked all the way up. I then proceeded to cut the Purple/Blue wire and VOILA--No noise. I reconnected it, drove and the noise reappeared.

So, I'm guessing this is the fix... Looking forward to others either validating these findings, or suggesting another fix.

 

[Anon2015]

You're suggesting Purple/Blue disables ANC or am I missing something here?

 

[Rush]

Yes... Purple/Blue. The wire connected to it in the pic was just a quick connect for testing purposes; It's capped.

Actually, it would be great if someone without ANC could post a picture of their amp for comparison.

 

[jrodriguez_20807]

Mine does not have ANC where is the amp located at maybe I can snap a picture for you..

 

[Rush]

Mine does not have ANC where is the amp located at maybe I can snap a picture for you..

That would be great. It's in the jack compartment--driver's rear.