The Super Tigre GS-45 is a powerful motor. It probably wouldn't meet most standard definitions of "quiet," but there are some things you can do to reduce operating noise. Operating with a three-bladed (or four-bladed) propeller instead of a two-bladed propeller will help reduce overall noise. If the engine still seems noisy, try to fly at a high altitude so you don't have to listen to it so close-up.