Noise Solutions: "Ninety at nine feet"
Cheech,
Your field sounds like ours. A few years ago we banned gassers and required all planes must have muffler. Recently we have begun noise testing on our planes because we found that some plane with mufflers were quite loud but some of the newer twins without mufflers were quite. I contacted the AMA and they sent me some info on noise levels and how to setup the test stand. They suggest 98db at 9'. What we found with our planes was quite interesting,most of the planes were in the 92db range a few higher a few lower. We tested 2 gassers, a G45 and a US41, both came in at 98db. We also found that props were the culprit to alot of noise. Another interesting thing we found that some of the planes own fuselage made alot of noise, so isolation mounts were installed and reduced the db output 2db, amazing. Good luck with your field, by the way were are you located. We are in Riverwoods, IL.
Robert