[A-Man]

Originally Posted by swamp2

To add to the drone description:

Drone is a cabin acoustic resonant mode excited by a peak in exhaust airborne noise output (at right around an undesireable frequency). The sound in the air, past the tip exit travels back through the vehicle. The noise level inside the cabin becomes very sensitive to small rpm changes (on/off resonance) and gets much louder in this narrow range. You can feel the bass, stereo like frequency everywhere in the cabin and it is super annoying. It is one hallmark of a poor acoustic design and poor design in general. It needs to be designed out unless you are very lucky. It used to be more common as folks (buyers and the companies manufacturing) just did not care or did not have the expertise to fix it. Luckily now you can find many M3 exhausts with no drone.

^ wat he said