The noise pickup must be very close to the ear piece to allow proper and constant phase for effective canceling. Having a separate box would mean the phase would change if you moved your head so would't work.
I haven't noticed any "noise blanker" effect. There are surely minor errors in the canceling process but Bose seems the have it pretty well worked out. iPod music is great through them even at 40000 ft. :-) Brian , K0DTJ > On Dec 26, 2013, at 5:20, "N2TK, Tony" <tony....@verizon.net> wrote: > > Is there such a thing as a noise cancelling black box you can plug in a > headset such as the CM-500 and get good noise canceling? No knobs. Just an > ON-OFF switch like the headsets have. > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html