[Mr.T]

"Richard Crowley" wrote in message
...
dpierce wrote ...
Irrelevant. Take a signal, run it through ANYTHING
that inverts the phase. A transformer, an inverting
op amp. No discrete sampling, no DSP of ANY
kind required.

But that's not how noise cancellation works. That method
would merely create acoustic feedback.

You do know the difference between positive and negative feedback right?
*Negative* acoustic feedback is actually what they are trying to achieve.
And Dick specifically said to invert the phase, i.e. negative feedback.

MrT.