Final word on noise cancellation-----
GM customer service set up a meeting for me with a cadillac technician to answer questions including one regarding showing me that the noise cancellation is working. He said that the noise cancellation does not go through the Bose system except for the speakers. The system cannot be turned on and off, and the noise that is being reduced by cancellation is only the drive train sounds, not road noise or any other noise. This tech gave me the most convincing information of the systems operation in our ST4 Sport, and I am pretty well satisfied that it is good information. I'm done with this issue.
GM customer service set up a meeting for me with a cadillac technician to answer questions including one regarding showing me that the noise cancellation is working. He said that the noise cancellation does not go through the Bose system except for the speakers. The system cannot be turned on and off, and the noise that is being reduced by cancellation is only the drive train sounds, not road noise or any other noise. This tech gave me the most convincing information of the systems operation in our ST4 Sport, and I am pretty well satisfied that it is good information. I'm done with this issue.
