Hi
cholmondeley
The "normal" Bose X (high impedance) work just fine in the Robinson (I've used mine in around five R22s and one R44). If you have problems in any particular helicopter, it's probably due to an impedance mismatch between the two headsets in the helo. However the high-impedance Bose seems to play well with all DC's on most all intercoms.
PS - the low-impedance is for military/NATO aircraft - the mic will not work in civilian aircraft, even if the plug is the same.
bladewashout, muffin the ANR of the Bose attacks large amplitude noises but has little effect on small ones. When I switched from DC 10.66's to the Bose, I was amazed at the additional noise detail suddenly apparent - transmission, tail-rotor, heck I can even hear the sound of the 300's clutch actuator over the engine and rotor on startup. At 70KT with both doors off I still hear the beeping voice-mail alert on my phone (oops, forgot to turn that rascal off...). With ATC, I always hear more than the dude sitting next to me in the DCs (and yellow foam plugs stuck in their ears), although it is sometimes a battle dealing with the volume turned up to earsplitting levels because THEY can't hear it. There may be ANR headsets which mask important sounds, but in my experience, not the Bose.
And Muffin, you may well hear more without a headset at all, but not for long...
