[blackvl]

It's one of the selling points for the CT.

Just wondering though, how does one know if it's working? I guess that environment is always there, but what happens if there's some sort of malfunction? How would I know if it's working or not? Is there some way to test it?

Thanks, Vince.

 

[chefmark]

Good question, I would venture to say you may never know unless you can really hear the difference. I wonder if there is a way of turning it off?

 

[Crashmaster]

Active Sound Control (ASC) uses the audio system to reduce engine noise inside the cabin. The system is linked to the throttle position and the engine's rpm to tune the V-6's sound, based on how it's being used. During normal cruising, ASC provides a quieter cockpit. During higher rpm situations, the system allows the more desirable notes of the engine's sound to be heard, to enhance driving enjoyment.

ASC system uses a mic in the cabin to "listen" for excess noise and vibration. When it hears this sound, the system generates sound waves that are complete opposite of the unwanted sound; to in effect, cancel out the sound. This sound is played back by the head unit though the speakers.

You might be wondering why would someone want to turn this off? For many reasons: Perhaps someone upgraded the stereo or speakers and it is not compatible with the ASC. Often after upgrading, you will get a buzz or popping from the new stereo due to the ASC.


But to try and answer your question: Basically, the ASC is integrated into the Honda Computer system to cancel noise and to my understanding it cannot be disabled, without manually cutting wires. To attempt this, you would need the CT Shop Manual to examine the schematics to know where and which wire to cut. Some people say that just disabling the microphone will turn off the ASC.

Hope this helps.

 

[blackvl]

Hey thanks for the feedback, but back to my initial question....how do I know it's working?

 

[chefmark]

Active Sound Control (ASC) uses the audio system to reduce engine noise inside the cabin. The system is linked to the throttle position and the engine's rpm to tune the V-6's sound, based on how it's being used. During normal cruising, ASC provides a quieter cockpit. During higher rpm situations, the system allows the more desirable notes of the engine's sound to be heard, to enhance driving enjoyment.

ASC system uses a mic in the cabin to "listen" for excess noise and vibration. When it hears this sound, the system generates sound waves that are complete opposite of the unwanted sound; to in effect, cancel out the sound. This sound is played back by the head unit though the speakers.

You might be wondering why would someone want to turn this off? For many reasons: Perhaps someone upgraded the stereo or speakers and it is not compatible with the ASC. Often after upgrading, you will get a buzz or popping from the new stereo due to the ASC.


But to try and answer your question: Basically, the ASC is integrated into the Honda Computer system to cancel noise and to my understanding it cannot be disabled, without manually cutting wires. To attempt this, you would need the CT Shop Manual to examine the schematics to know where and which wire to cut. Some people say that just disabling the microphone will turn off the ASC.

Hope this helps.

Kind of, so what your saying is that they are 2 different systems and the ASC is controled by the ECM computer?

 

[Crashmaster]

Hey thanks for the feedback, but back to my initial question....how do I know it's working?

To my research, there is no fuse you can pull or wire you can quickly disconnect to test the ASC system. The only test I’m aware of is to apply a thick padding around the microphone, preventing the counter balance sound, thus, you should hear more road noise and vibration. You would probably need a shop manual to locate the microphone, and when you find it, hold a thick wad of damp rags, which will prevent the sound from getting to the microphone. Then by covering and uncovering the microphone (while driving on a noisy bumpy road) you should be able to hear a difference. My guess is that you won’t hear a big difference. You might even have to remove a panel or so to get closer to the microphone.

 

[blackvl]

Hmmm, sounds like a bunch of hoo-haa, hocus-pocus if you ask me. Honda pitches this is the neatest thing since sliced-cheese and convinces everyone what a wonderful grand doo-dad ASC is, when none of us can know for sure, whether its working or not. How do other luxury vehicles deal with cabin noise? The CT is a quiet running vehicle, but is it more the result of quality engineering, sound-deadening materials, and quality components, rather than a bunch of white noise being piped over the speakers? No one knows for sure, eh?

 

[Crashmaster]

Bose noise canceling headphones work on the same principal. At least on these headphones you have the opportunity to turn the noise canceling off and on and can actually hear the difference.

Dual microphones - one located in the headliner near the overhead console and the other near the rear overhead light module - pick up low-end drivetrain frequency noise entering the cabin. This audio signal is sent to the Active Noise Control electronic processor, which creates and sends a precisely timed "reverse phase" audio signal to a special amplifier. In turn, the amplifier drives the door speakers to cancel the original noise signal.

ANC dramatically reduces the booming sound of the exhaust for passengers in the front as well as rear seats. In the frequency range below 100 Hertz, ANC results is a remarkable 10 dB reduction in noise level.

I found the below on how to disable the ANC for a Honda Pilot. It could be the same for a CT??

Service Bulletin
© 2006 American Honda Motor Co., Inc. – All Rights Reserved ATB 34078 (0612) 1 of 1
CUSTOMER INFORMATION: The information in this bulletin is intended for use only by skilled technicians who have the proper tools, equipment,
and training to correctly and safely maintain your vehicle. These procedures should not be attempted by “do-it-yourselfers,” and you should not assume
this bulletin applies to your vehicle, or that your vehicle has the condition described. To determine whether this information applies, contact an
authorized Honda automobile dealer.
December 22, 2006
06-092
Applies To: 2006 Pilot – All LX 2WD models
2007 Pilot – LX 2WD models from VIN 5FNYF2...7B000001 thru 5FNYF2...7B006392
Booming or Humming Noise From Speakers While Driving
SYMPTOM
A booming or humming noise is heard from the
speakers while driving with the radio on or off.
PROBABLE CAUSE
A faulty ANC (active noise control) unit.
CORRECTIVE ACTION
Replace the ANC control unit.
PARTS INFORMATION
ANC Control Unit: P/N 39200-STW-A02
H/C 8563413
WARRANTY CLAIM INFORMATION
In warranty: The normal warranty applies.
Operation Number: 0101C9
Flat Rate Time: 0.6 hour
Failed Part: P/N 39200-STW-A01
H/C 8159055
Defect Code: 03217
Symptom Code: 04201
Template ID: 06-092A
Skill Level: Repair Technician
Out of warranty: Any repair performed after warranty
expiration may be eligible for goodwill consideration by
the District Parts and Service Manager or your Zone
Office. You must request consideration, and get a
decision, before starting work.
DIAGNOSIS
1. Start the vehicle.
2. Turn the radio on, and make sure it operates
normally.
3. Turn the radio off.
4. Press and hold the preset buttons number 1 and
number 6, then press the VOL push PWR button.
The audio system enters its diagnostic mode and
Diagnosis (or Diag) appears on the display.
Release the preset buttons.
5. Press the number 1 preset button. ANC ON
appears on the display.
6. Press the number 1 preset button again to turn the
ANC OFF. You should hear a humming noise
coming from the speakers for about 60 seconds.
NOTE:
• To turn the humming off, press the number 1
preset button to turn the ANC ON, and wait for
the hum to stop. Press the number 1 preset
button again to turn the ANC OFF.
• Repeatedly pressing the number 1 preset button
cycles the audio unit ANC ON and ANC OFF, but
the ANC control unit won’t hum until the ignition
switch is turned on and off, and you put the audio
system back into Diagnosis mode.
• When the ignition switch is turned on and off
again, the audio system defaults to its ANC ON
mode.
7. With the ANC OFF (audio unit on), test-drive the
vehicle as described by the customer. If you can’t
reproduce the booming or humming noise, go to
the REPAIR PROCEDURE.
8. If you can still hear the booming or humming noise,
disregard this bulletin and do the ANC
troubleshooting in the service manual.
REPAIR PROCEDURE
1. Replace the ANC control unit.
• Refer to page 22-345 of the 2006–07 Pilot
Service Manual, or
• Online, enter keyword ACTIVE and select Active
Noise Control Removal/Installation (2WD)
from the list.
2. Test-drive the vehicle to confirm the repair. ​

 

[Army Dad]

Thanks for the explanation Crash, and especially for the great info on the Service Bulletin.

 

[schaloupka]

I went into diag mode by hitting the 1, 6 and volume all at the same time. when I hit a 1 after that I see... NPU1 on Max 16...does anyone know what this means? I believe my Active Sound Control is not working.....I have a 2010 crosstour EX-L

 

[salesrep]

One of my previous vehicles was a 2005 Accord Hybrid that also used the same technology with the ANC system of "listening" for what was typically ECO-mode cylinder deactivation drone noise making its way into the cabin and creating opposite-phase sound pulses to cancel them out. Not sure if the Crosstour system is completely identical, but I would imagine it's at least based on the Accord Hybrid system--and how much farther back from there, who knows. . .

Other than entering a diagnostic mode or cutting wires or removing the stereo system, you would basically only hear a malfunction during cruising speed when cylinder deactivation occurs. Either you'll hear a certain droning sound coming from the engine that you've never heard before, or you'll hear a low-frequency vibration sound coming from the speakers when the ANC system is trying to function but part of the system has failed--the amplifier, for example. Before I bought the Accord Hybrid, I test drove another one and when i got the car up to highway speed it kept generating the low-frequency hum through the stereo system--at the time I had no idea about any of this, but only as I discovered more about it later on did I realize what I had encountered.