I just performed this mod yesterday. My adjustment was from xAxx to x8xx. Worked. My understanding of the change is to subtract 2 from whatever value is found. So if your original value was x2xx, then you would change to x0xx. Could you have originally been x2xx?
I don't think so. I was very careful to double check all numbers; both to make sure I was on the 727- line, and to make sure I was changing the correct digit in the series. I know for certain the system was disabled because I heard a thump from the subwoofer when I wrote the change back to the computer, and normal whooshing sound you hear when you turn the ignition on without starting the car was gone. When driving after changing the car was eerily quiet. Just to be sure I had done it correctly I went back and changed the "0" back to "A" and re-enabled the system. I again heard the thump from the subwoofer, when writing the values, and the whooshing sound and fake engine noise were back.
Nope, I'm positive the fake engine noises were disabled. As I mentioned, I heard a thump from the subwoofer when writing the values back to the computer, and the car becomes eerily quiet when driving--absolutely no fake engine noises (my exhaust is stock, so I can't really hear it at all).
In this thread, we are not looking for a way to disable the fake engine noises (better known as the Engine Sound Enhancement or ESE) but rather for a way to disable the ANC. The deactivation of the ANC and the ESE is done by changing different values. I have deactivated the ANC but still have the ESE. Maybe deactivating the ESE is what you need for your subwoofer @TorqueMan (although I doubt), but those looking to get rid of the drone of an aftermarket exhaust have to deactivate the ANC, and this is done by changing the values I described above. Maybe someone with knowledge on hex numbers can chime in and explain this.
This is EXACTLY my point @Radiation Joe ! If you read the description in the spreadsheet in your post, you will find out that by replacing this digit with a "0" you disable the Fake Engine Noises (aka Engine Sound Enhancement or ESE), not the ANC.
I disagree with this. The ANC is meant to cancel out noise at frequencies between 30Hz and 180Hz, so it seems to me leaving it on will actually help to MUTE exhaust drone in that frequency range. That's it's stated purpose: to reduce exhaust, engine, wind, etc. noise the driver and passengers hear. The ESE adds to cabin noise and has the potential of resonating with the exhaust system when the exhaust note is at the same frequencies as the ESE.
I only mentioned the thump of the subwoofer as a way to tell that I had actually made a change to the ACM. I could hear the thump when I saved the changed value.
It appears setting the digit to "0" disables the ANC and tells the computer there are no front tweeters, while changing it to "A" turns off the ANC without affecting the tweeter setting. I didn't notice a difference in the way the stereo system sounded when I had the digit set to "0," but I'm going to test it to see if it turns the tweeters off.
The way I read this spreadsheet, the digit in question affects four options:
Ok, I don't want to keep answering both, so let's just keep this discussion public.
Roger that; this is how I understood the fake engine noise (ESE) to work. The problem, though, is that you keep distinguishing between ANC and ESE; there is no provision to enable/disable these two systems independently of each other using the data in the spreadsheet. According to the spreadsheet, the ANC (fake engine noise) should be disabled with the digit set to 8.
I think you have a fundamental misunderstanding of how noise cancelling systems work. Click here for a good discussion. The ANC system does not broadcast pre-recorded sounds, that's what the ESE does. The ESE system broadcasts pre-recorded engine noise through the car's speakers. The ANC system listens for noise in a specific range (which I believe is between 30Hz and 180Hz) using the microphone in the cabin and cancels out only what it hears. The ANC doesn't generate any noise not first heard by the mic in the cabin. Assuming it is functioning properly, the ANC system cannot make any noise louder. I suppose it's possible that by canceling out lower frequencies higher frequencies might become more noticeable for some; everyone's ears are different.
Based on the data in the spreadsheet, setting the digit to 8="FT present & CS: North American & ANC absent & USB absent." The column header says "FT" is front tweeter; "CS" is chime strategy; "ANC" is fake engine noise (it doesn't define "USB"). I'm betting you disabled the ESE (fake engine noise) by setting the digit to 8. I also suspect that setting the digit to any value that equals "ANC absent" disables both the ANC system AND the ESE system, which would explain why Radiation Joe's wife perceives more road noise with the digit set to 8. I suspect the ESE functions in some sort of test mode while you are activating map slots with your AP. You can test my hypothesis by activating your map slots with the digit set to "0." I believe you will still hear the fake engine noise even though you will have disabled ESE in the computer. I'm going to test whether ESE is disabled in my car with the digit set to 8. I know for a fact it's disabled when set to 0.