Geistware, not to start an argument here but Carroll specifically said 3-D. The very nature of 3-D and high alfa flight requires RPM's in the mid to upper rpm range where throttle response is at its best. The Brison should twist 7200-7500 static according to Gary Allison at Brison engines. 3-D is throttle happy flying and if you can't use your left thumb your not ready to try. As far as prop noise, the shape of the tip has a lot to do with that. I think a Pro Zinger at 7000 makes less noise than a Master at 6000.