RE: DA-50 noise restrictions?
I can only offer observations, since I don't have a DA50. The DA50s that I have seen are pretty loud w/ a Pitts muffler. I have a BME50 w/ Pitts muffler, and I think it too is pretty loud. The Pitts mufflers also sound rather "harsh". I also have a 3W-75 w/ a canister muffler that I have a hard time hearing when someone else is flying their .40 size trainer. The pipe would be much better sound wise than the Pitts, but the Pitts is probably still "legal" -just much louder than your other options.