Active Noise Canceling

As of late our shop is seeing more and more vehicles that have active noise canceling coming in for subwoofer installs. I am curious to see what everyone in the industry is doing about this issue. The issue is, when you install a subwoofer into a car with ANC, the ANC system makes the woofer hum or altogether freak out when the vehicles engine is started or at certain rpm's. Some cars we have dealt with, we just disconnect the mics in the headliner and be fine however if you do this, you loose your bluetooth mic as well and 99% of customers don't want to loose hands free calling and voice control. Also this is for when the customer wants to keep the factory head unit. So please weigh in on what your shop has done to get past the annoyance of Active Noise Canceling.

Brad
Install Manager
Quality Auto Sound
Greeley Colorado

The bluetooth mic is separate from the anc microphones. Honda Accord vehicles you have to disassemble the front microphone assembly, the microphone nearest the driver is the bluetooth microphone. The one on the right side of the module needs to be cut off of the circuit board. The rear one needs to be cut as well.

GM trucks and Suv. the bluetooth mic is the one directly in front of the drivers head. All other microphones need to be cut or unplugged. There is 1 on each side inside the handles mounted on the roof. You have to remove the handles in order to get to the wires of those 2. The 1 in rear of headliner needs to be unplugged as well. It is not easy to get to.

On the back of some honda radios there will be a plug that you can disconnect that will turn off the ANC and retain the bluetooth mic

https://www.hondaaccordforum.com/forum/attachments/audio-visual-electronics-10/16231d1461350732-active-noise-cancelling-fix-issues-when-adding-sub-20150711_134907.jpg

Found this today, it may help get to the rear microphone via the domelight. I will let you know if I do one and it is right there. If somebody else does one and it is as pictured please let us know.

i am an idiot wrote:

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https://www.hondaaccordforum.com/forum/attachments/audio-visual-electronics-10/16231d1461350732-active-noise-cancelling-fix-issues-when-adding-sub-20150711_134907.jpg

Found this today, it may help get to the rear microphone via the domelight. I will let you know if I do one and it is right there. If somebody else does one and it is as pictured please let us know.

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Do you know if the ANC is tied into the low level audio signal in the stock amplifiers or do they have their own signals?

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Rumors of Bob but never Bob......So what is it you tell people you do these days Bob?

Forget it,I just got a very detailed wiring diagram from my friend(gm certified mechanic) of the Infotainment,radio etc systems and a lot of my questions are answered.I now know what causes that humming people are talking about and pulling the microphones works but it is not the optimal way to do it.In fact,that disables the ANC system whereas the proper way to do it keeps the ANC in tact.

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Rumors of Bob but never Bob......So what is it you tell people you do these days Bob?

jh1973 wrote:

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Forget it,I just got a very detailed wiring diagram from my friend(gm certified mechanic) of the Infotainment,radio etc systems and a lot of my questions are answered.I now know what causes that humming people are talking about and pulling the microphones works but it is not the optimal way to do it.In fact,that disables the ANC system whereas the proper way to do it keeps the ANC in tact.

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Will you be sharing this new knowledge in the forum?

I too would like to see how you pull that off. The way the anc cancels the noise is to shift the noise 180 degrees and inject it into the system and thus cancelling out the noise. So if the system is "working" it is injecting non musical sounds into the system. The subs play this as non musical noise. I am really curious to know the right way to do this without disabling the microphones.

OK,here is the deal guys,I build amplifier bypass harnesses for these Equinox and Terrains.My T-harnesses for the amplifier plugs do not contain the 5 ANC wires in the speaker out plug so that basically shuts the ANC system down.That being said I am testing a theory and will know soon enough if it works a way to retain ANC functions while installing a subwoofer amplifier and sub at the same time.I apologize for stating it like it was a done deal.I have a tendency to get out ahead of myself.In any case,I know for sure that retaining ANC functions and bypassing the stock amplifier at the same time is NOT going to happen.I thought it could until I studied this detailed wiring diagram which clearly reveals how the ANC module is related to the stock amplifier.

Edit.....I may just well be able to bypass the stock amplifier and keep ANC functions in tact.It is a work in production and I will be making a new post when all of my research and testing is complete.

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Rumors of Bob but never Bob......So what is it you tell people you do these days Bob?

The ANC module receives reference signals from the microphones at various places in the vehicle.It then sends a signal to the vehicles stock amplifier which in turn shoot those signals through the designated speaker wires and out the speakers(and/or subs).When you tap those speaker wires and use that for a signal you are sending both ANC noises and audio signals into the new amplifier.Hence the annoying humming noises coning through the new subwoofer.

The fix.....Get a signal for the new amplifier by tapping the low level inputs from the stock head unit BEFORE they hit the stock amplifier.This accomplishes a few good things....

1.No ANC humming noises being amplified
2.ANC stays fully in tact and the customer now enjoys premium audio and the benefit of an ANC system.Basically they can have their cake and eat it too.
3.No need for a line out converter and the signal degradation that goes with it.You are now taking a low level signal and amplifying it once which is the ideal way.You're not taking a signal and amplifying it then lowering it and then amplifying it again.

I have had many happy happy customers that use my audio integration harnesses which utilize the principles explained.Keep in mind that my knowledge is that of GM ANC systems from 2010-2017.I'm not sure if these systems change from different manufacturers.

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Rumors of Bob but never Bob......So what is it you tell people you do these days Bob?