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.
Noise-cancelling headphones. Noise-cancelling headphones are headphones that reduce unwanted ambient sounds using active noise control. This is distinct from passive headphones which, if they reduce ambient sounds at all, use techniques such as soundproofing.
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.