EZ2BEVILC5

Hello,

I ran an amp and two 12" pioneer shallow mount speakers in boxes through the high level inputs on the rear side speakers. Long story short getting a loud constant feed back noise when I hit the accelerator pedal. After trouble shooting, I narrowed it down the the closure of the rear hatch. When it is cracked no feed back. Anyone know what changes when the hatch is closed and which wire would I need to insulate or what I need to do?

Thank you,

KenHorse

It's not alternator noise?

EZ2BEVILC5

Its not a wine and only with the hatch unlatched...?🤔🤔

Matthewstorm

Did you happen to also install the NAV-TV GM650 along with the that Amp? Cause, if you didn't you're gonna have lots of problems.

Guard Dad

I’m not the last word on this but I think this is a result of him accidentally messing up the automatic noise cancellation function of the Bose system. Worth considering.

EZ2BEVILC5

Can you give me more info on this?

EZ2BEVILC5

I didnt. This is the only problem...

Jaykoh-Z51

the Bose system has some noise cxl input...theres a wire under the rear floor..bose amp area. I believe if you disable the noise cxl, this 'could' help.

Pretty certain an add-on amps require us to disable this.f

I'm not an expert tho...just going off of all the "adding subwoofer" threads recently.

Guard Dad

As I recall their is a microphone on each B pillar that monitors ambient noise and the Bose system generates out of phase sounds to reduce the cabin noise level. I think the speakers that you are using as your source are part of that system, if so, you’ve thrown the system out of balance, hence your problem, the system is fighting itself.

Look, I really am on thin ice here, I ran across this information on another thread while researching replacement of the front door speakers and the OEM subwoofer. My take away was don’t mess with the microphones or the fill speakers unless you know what you are doing. I’m sure that there are many folks on the forum that have WAY more knowledge on the topic. My advice is to do more research and see if my observations are relevant to your situation.

EZ2BEVILC5

For everyone, just disconnect the speed sensor plug and it takes care of the problem. You don't even have to cut the wires and modify anything.

Matthewstorm

What speed sensor plug?

JerryU

^^
Good question!! Love solutions that assume far more than you would naturally know. Where is it and if you can’t take a pic than a clear description of the location would be helpful.

Reminds me of iPhone solutions that assume you know how to get to the third step where they start!

Chance575

As stated above you need this

NAV-TV GM650

DWillys

NAV-TV GM650 -> DSP -> Amplifiers -> new speakers.

PAC has an interface you can use instead of the NAV-TV but it seems people have been having the best results with the NAV.

The OEM Bose system does a bunch of frequency/volume manipulation based on ambient noise, engine speed, how loud you have the stereo volume set, etc. The entire Bose setup is designed to work together. Change out one part and you will get weird results. Using the NAV takes all that away, you get a clean unadulterated signal.

I just finished my install. Compared to the original Bose, well, try driving a Yugo and then a Z06. Notice a difference?

JMII

Correct... you can't just grab the factory signal after the amp. You need an OEM interface. So one of these units:
M650-GM - NAV-TV
AX-DSP-MOST1
AP4-GM61

ersatz928

You must disconnect the two noise cancellation microphones. The 2 wires are easily cut, or removed at the connector at the Bose amp, under the cargo floor panel. The below post shows how to do this.

https://www.corvetteforum.com/forums/c7-tech-performance/3732274-how-to-install-a-sub-amp-from-start-to-finish.html

Matthewstorm

But why would you want to disconnect these?

ersatz928

Disconnect the mics to eliminate the engine speed related feedback noise the the original poster is getting from his add-on subwoofer.

bartsky

Did this recently, worked perfect!

GeoGS

Well, reading all these post on noise cancellation problems, I decided it is not worth trying to add reverb for just a few songs, well maybe several. I was going to use the back speakers for the reverb unit. I would have to disconnect them, use the feeds to go to a L.O.C., to bring the levels down then the output of the L.O.C. to the reverb unit, then the output of the reverb has to go to the input of another amp, then out put that to the 2 back speakers. This would have been a new all electronic unit no springs. Yes, reverb is not for every one. Not for every song. But for some it does work. It took me a while to find a new reverb out there for a car. As they still make hundreds of different kinds for the stomp pedals for guitars. I can only imagine the problems of what the sound would sound like, trying to fight itself with the noise cancellation. Here is the URL for the new unit and in one of the pictures in the listing they show the simple schematic, and the output has to go to an amplifier. https://www.ebay.com/itm/Color-Bar-P...UAAOSwuMRb-3IB