Most of the time I fly solo but w/ a passenger
the inherent loud noise from the engine
 even with a muffler interferes with the
intercom mode of the Bendix/King kx125 nav/com.
  I am thinking that I will have to buy a
separate intercom for noise attenuation. Does
 any one have a recommendation for a manufacturer/model?

 John P

 Just curios John. What does your muffler system look like.
 Got any pictures? Are your rotor housings turbo type
 or normally aspirated?


 Paul Lamar

 The engine is normally aspirated w/ a Stainless works -Smooth tube
muffler st252425 which is under hung out in the breeze. 240 hrs on
it to date. Will send a picture next week.

John P   

Thanks John. I assume the rotor housing exhaust ports look like
this?

The muffler looks low aero drag. Sounds like it would be a good second
muffler along with a tangential under the cowl to quiet the system
further if it is too loud by itself.

Hear are the specs on this Smooth Tube 304 SS muffler.

"2 1/2" ID, center inlet/outlet, standard
finish. Exclusive louvered core creates a sweet
"Street Rod" deep tone that is not overly
aggressive. On a 1-10, 10 being the loudest,
these mufflers are a 7. Mufflers are sized so
that they can be reversed for an even more
aggressive sound. Can be welded or clamped in
place.
**PHOTOGRAPH SHOWS POLISHED MUFFLER PART NUMBER ST252425P**"

I would get one of these Harbor Freight Cen Tech Wireless inspection Camera
and keep an eye on the guts from time to time to make sure they are
not melting.

Paul Lamar


 My coot is the loudest plane I have ever been
in, I use a PS engineering aero com 3 intercom
which is the best on the market for noisy
cockpits and David Clark noise cancelling head
sets.
 Ken