This has to do with the drivetrain of the car. In simpler terms, the power delivery system of the car. A 2wd or a two wheel drive is any general stick shift(manual transmission) car you drive. Either the front two rotates and pull your car or the back two rotates and push your car forward. For a 4wd or a four wheel drive, you can switch to all of the wheels being driven. Provides better grip on the road.
How the system works. 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.
TIPS TO ELIMINATE THE ECHO. 1  For those using external speakers, position the speakers away from your laptop microphone and try reducing the volume. 2  If you are using external microphones, position it about 12 inches away from your speakers. 3  Try downloading the latest version of Skype that has a built-in Echo Cancellation feature which detects and ... Try reducing the volume level of the microphone to 50% or turn off the mic boost option. 2  Try downloading the latest version of Skype that has a built-in Echo Cancellation feature which detects and reduces the echo. 3  Try using a headset or headphones instead of speakers and microphones, if none of these suggestions work.