If I read this correctly the speaker and amps are used to drown out road and engine noise. For those who have changed out their speakers and amp for aftermarket. Are you noticing more cabin noise ?

Active Noise Cancellation(TM)
In order to provide a more hushed driving environment during highway cruising, the 2007 TL Type-S uses Active Noise Cancellation(TM) (ANC), which is designed to dramatically reduce low frequency exhaust booming 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 headliner, one in the front passenger cabin, and another in the rear. The microphones capture low-end drivetrain frequencies entering the cabin, and send a signal to the Active Noise Cancellation unit hidden in the dash. 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 deck.

Since the system is designed to cancel low-frequency sound, it doesn't use any of the audio system's tweeters. The system dramatically reduces the booming sound of the exhaust, front and rear. In the rear seat, "boom" is reduced by a very impressive 17 db.

 

changing out the speakers wouldnt affect the ANC because the speaker should still be receiving the same signal

 

It's fine to install aftermarket speakers but if you go with aftermarket subs you have have to disable the ANC.

 

What they said.

It's a gimmick anyway.

 

I heard it has something to do with making extra noise in the system....I could be wrong though.

 

Yep, that out of phase low rumble it's designed to make to match the exhaust rumble is now many times louder with aftermarket subs and 10x the power. In theory you don't notice it or the exhaust when stock because they're the same level and it's 180 out of phase (just like wiring two subs opposite one another produces no bass). Once you add power and bigger more efficient subs with a different frequency response that rumble becomes a problem.

Most people who have gotten rid of ANC say they can't tell a difference or it's minor. I guess you could keep the ANC if your aftermarket sub matched the response and level of the stock setup but there would be no point.

 

Thx for all the great comments