11-19-2010, 07:55 PM
Location: Ontario, California
Thanked 201 Times in 161 Posts
Feedback Score: 30 reviews
REFERENCE: Honda ANC
NOTE: I am not responsible for stupidity, or breaking of ANY components to the vehicle.
- This thread is solely for Honda's equipped With ANC. please use google to search if your vehicle is equipped with this, works in conjunction with Honda's that have VCM.
- This is also ONLY if you are using the stock Head unit with either a LOC, Line Driver etc.
- ALSO if you are searching for a remedy to a higher pitched hum through the door speakers OR a Heartbeat Like Pulse through the sub woofer OR BOTH ONLY WHEN THE ENGINE IS ON then you have found the right thread!
First 0ff what is ANC?
Active Noise Cancellation (ANC) is designed to dramatically reduce low frequency noise in the interior. The system operates whenever the car is running, regardless of whether the audio system is on or off.
There are two microphones in the cabin area.
The microphones capture low-end drivetrain frequencies entering the cabin, and send a signal to the Active Noise Cancellation unit. The control unit then creates a precisely timed reverse phase audio signal that is sent to an amplifier, which powers the door speakers and the subwoofer positioned on the rear parcel shelf.
Since the system is designed to cancel low-frequency sound, it doesn’t use any of the audio system’s tweeters. The ANC dramatically reduces exterior noise. In the frequency range below 100 hertz, ANC results in an impressive 10 dB reduction in noise level." -Honda.com
What does this mean when adding Aftermarket Audio products to your vehicle?
After installing in a friends car yesterday everything was said and done and all tidy like. Turned JUST the key to Acc. Sounded great. Once we turned the car on a god awfull heartbeat like sound came blasting through the woofer. extremely irritating.
After Making sure it was not a ground loop issue OR RCA issue i had nothing left... felt lost. I then turned to the internet to do some re-search on the car Make and model. Found countless threads with very scattered information. I then found ONE thread in particular which led me to believe it was this ANC as the culprit. We noticed that when the door was open with the engine on it would go away. Reading a manual it states "** Note: ANC is de-activated when any door is open" which gave it away.
Now to fix this issue.
- Before reading on make sure this is the ANC causing your issues and not a ground loop issue or bad rca's SIMPLY by opening a door with the engine on and see if the noise's go away.
- Upon finding out IF indeed the ANC is the issue here is a simple way to TEMPORARILY DE-ACTIVATE IT
YOU HAVE NOW COMPLETELY DE-ACTIVATED the ANC module.
- Turn the Key to the ACC Position
- Turn Off the STOCK headunit
- Press the 1 and 6 buttons. While holding theese press the On or Volume button.
- You should now be in the Diagnostic Mode. It will display either "DIAG" or "DIAGNOSTIC" on the scree
- Now press the 1 button again. you should now c what says ANC On
- Press the 1 button again to TEMPORARILY Dissable the ANC of turn it off.
- You should now hear a Loud 50-100hz tone coming through all your speakers. Dont fret! Simply turn the car on from the acc position and start the engine.
- Now the ANC is TEMPORARILY off.
- Take the car for a test spin and noptice if all the noises are gone either the Boom from a subwoofer or whine from the door speakers. IF it is gone go back and park your vehicle. If it is still there you DO NOT have an ANC issue. check for a ground loop issue OR RCA problem from the LOC , EQ or Line Driver.
- With the vehicle parked pop the hood and disconnect the NEG. terminal on the battery.
- Now remove the stock HU using instructions which can be found elsewhere online. NOTE Trim bezzels are often held in by small metal clips. dont be afraid to pull hard!
- With the stock HU No free, pull it out and get a clear view at the back of the HU
- There should be a Blue harness. this is the stock harness which houses the Speaker output's and 12v+, 12v switched, and GROUND.
- Directly next to that there will be a harness that is white. THIS is where the ANC module plugs directly into the radio. This is where the subwoofer leads are hooked to. If the car is equiped with a Stock subwoofer then there will be SEVEN wires coming from this harness. if not FIVE wires will be present.
- Disconnect said harness from step #14
- Replace the HU and any trim pieces/bezels.
- Connect the Ground terminal at the battery and shut the hood.
Check if all noises are gone by turning the car on. If they are gone GREAT! if not you shouldnt be this far hah!
Tags: ANC, heartbeat sound, Whine, Honda, LOC, issues