[geaux_tigerss]

I’ve had an issue to which I’ve recently figured out the solution and I thought I’d share.

After installing my long tubes and tuning I noticed some weirdness in the sound doing high load pulls during the top of the rpm range with the windows up and NPP open. I drive with windows down a lot so this is a bit of a distinction. It almost sound like it was running rough or missing or the ecu was pulling spark. This was strange to me because my datalogs showed everything was good, it pulled great (no driveability issues), and with the windows down it sounded great. I wasn’t the only one that noticed the weirdness either. One of my buddies (also a tuner, but more of a vette guy) pointed it out when we rode somewhere.

I was reading a post about subwoofers messing with the active noise cancellation on the 2SS models and it occurred to me that this could be my issue as well. As an experiment I decided to disable the ANC at the amp and test drive. The problem went away 100%. I reconnected it and it came back.

Long story short, the ANC microphones are picking up the exhaust noise with the NPP valves open during high load pulls while the windows are up and it tries to cancel it which just results in things sounding bad.

Just something to check if you guys are having a similar problem. I haven’t discovered any downsides to disabling the ANC yet. I think this will only affect 2SS models since they have the ANC Bose amp. 1SS and V6 models should t be affected.

[Joshinator99]

First I’ve heard of this, but since I’m planning on adding headers, I’m glad you brought it up. How did you disable the ANC? I didn’t even realize we had that on the 2SS...lol

[6spdhyperblue]

Makes sense. Good post

[geaux_tigerss]

Originally Posted by Joshinator99

First I’ve heard of this, but since I’m planning on adding headers, I’m glad you brought it up. How did you disable the ANC? I didn’t even realize we had that on the 2SS...lol

As with anything, there are options. I just pulled the X3 connector on the bose amp in the trunk. This has the added problem that my turn signals don’t work and the reverse parking sensors don’t chime. I’m sure there’s a few other things as well (key left in vehicle warning, etc.) - basically all chimes. This is fine for troubleshooting purposes, but not long term.

Long term there are 3 options:

1. Install an ANC delete harness. This is what I will be doing. I ordered it from ********. It was $23 shipped. This is the simplest and least intrusive option.

2. Remove the door panels and disconnect the microphones. Supposedly you only need to do one side. This is simple, but a little more involved and, at least imo, opens you up to broken clips and rattles. If you’re removing the door panels anyway, this is a great free option.

3. Cut the wires at the plug in the amp. You only need to cut one side of the microphone wire to disable it. There are pinouts of the Bose amp on this site if you search. This is also an easy, free option.

[Joshinator99]

Originally Posted by geaux_tigerss

As with anything, there are options. I just pulled the X3 connector on the bose amp in the trunk. This has the added problem that my turn signals don’t work and the reverse parking sensors don’t chime. I’m sure there’s a few other things as well (key left in vehicle warning, etc.) - basically all chimes. This is fine for troubleshooting purposes, but not long term.

Long term there are 3 options:

1. Install an ANC delete harness. This is what I will be doing. I ordered it from ********. It was $23 shipped. This is the simplest and least intrusive option.

2. Remove the door panels and disconnect the microphones. Supposedly you only need to do one side. This is simple, but a little more involved and, at least imo, opens you up to broken clips and rattles. If you’re removing the door panels anyway, this is a great free option.

3. Cut the wires at the plug in the amp. You only need to cut one side of the microphone wire to disable it. There are pinouts of the Bose amp on this site if you search. This is also an easy, free option.

Great info, thanks again. That delete harness looks like a winner to me.

[Booher]

Pull the pins on the harness going to the amp, for the anc, do not cut anything. That is a common thing to do when installing an aftermarket amp in this car.

[L78toLT1]

Mine's probably doing this too, but I'm too old and hard of hearing to detect it lol!

[s346k]

i got the poverty trim option, no worries here.

[squish72]

Did yours sound like a consistent wave of sound? Almost like surging? I guarantee that's the sound I'm hearing and didn't dive too much into it as my logs wouldn't show what I was hearing. At the top end of the rpm range my car sounds like the rpms are not smooth at all. At first I was worried it was my tune but this is a solid possibility for me. Makes total sense

[RLNTLSS]

Is it that noticable... Sometimes i feel bass when im leavn home.. but im cammed and catless longtubed..i can feel bass kick up until my engine quites down after 6and 7 gear

[cmitchell17]

I didn't think the V8 SS's had noise cancellation? I am going to check the wiring diagrams, There are times my npp sounds good and times it sounds bad, and then I've heard YouTube videos of in car npp at WOT that sounded amazing and sounded very similar to the Corvette npp which sounds way better than the Camaro npp.

[geaux_tigerss]

Originally Posted by squish72

Did yours sound like a consistent wave of sound? Almost like surging? I guarantee that's the sound I'm hearing and didn't dive too much into it as my logs wouldn't show what I was hearing. At the top end of the rpm range my car sounds like the rpms are not smooth at all. At first I was worried it was my tune but this is a solid possibility for me. Makes total sense

Not really a constant wave, just that something sounded “off”, like there were gaps in the rpm range. It wasn’t the smooth roll of V8 scream that I’m used to.

[squish72]

Originally Posted by geaux_tigerss

Not really a constant wave, just that something sounded “off”, like there were gaps in the rpm range. It wasn’t the smooth roll of V8 scream that I’m used to.

Hmm weird the sound I'm hearing is almost like someone is turning the nob on a stereo up and down quickly. Like there is a rise and fall of the engine sound but only towards the top of the rpms range (when. It's at it's loudest). I'm betting that's what is causing what I'm hearing.

[Mov Ov3r]

Originally Posted by s346k

i got the poverty trim option, no worries here.

same