Yup, that jives with what I've seen. If you could cancel out the fundamental
and a couple of harmonics for a given direction, it's still going to be
freakin' loud.

"Jay" wrote in message
m...
The spectrum of the sound from the engine does indeed have several
strong harmonics that rise up from a random noise floor. I think
you'd be able to cancel the periodic components of the noise leaving
the random part behind. If I had to guess, you'd get rid of the buzz
and be left with the roar. So with cancelation it might be similar to
a jet turbine in sound.