ORIGINAL: cappaj1
The plane is suprisingly quiet for a 2 stroke. Got several comments including three 'noise committee members' that the plane was really quiet for a 2 stroke. I recommend using foam under the engine and against the firewall behind the mount along with an APC prop and the muffler diverter to help quiet the plane. Everyone I asked about the foam said it'd do nothing, but I feel it is helping considerably. It seems to work for me. Almost sounded like an electric up there - it was amazing! Of course throttle management and a well broken in engine seem to be helping as well.
Fully enclosed set-ups, whether 2 stroke or 4 stroke, will practically always be quieter than open, or partially coweled. Add a dead medium like foam to the mix and you will get even more quiet. If and when you go to a piped set-up, you will find a big difference between a pipe that is burried completely inside a belly pan and one that is only partially burried or not burried at all. Add a thin layer of foam to the belly pan and get even more quiet.