What are you guys running for exhaust? The thing is stupid loud and can barely talk on radio. Headset is LightSpeed wireless Tango's. Their ANR does not work well with the pitch of the rotary. Will try a Bose headset tomorrow.
I have 2.5" exhaust leaving the cowl. (ex1.jpg) It comes down and centers the bottom of the plane into a 4" outer pipe. (ex2.jpg) The 4" outer pipe (5ft long) is open to the free air and exits behind the rear bulkhead. The 2.5" converts to a 3ft long perforated pipe (ex3.jpg) and exits inside the 4" outer pipe. For fun, I filled it full of ceramic fiber insulation mat, which did help a little until it blew all out.