Thoughts for Future Speaker Designers

...and even then, latency would be an issue with speech. How can you damp everything in RT?  There's bound to be some 'leakage' that would be experienced.  Noise-canceling headphones work on aircraft because the turbines and the fuselage of the craft are a form of white or pink noise, which is relatively easy to damp out.

"I may be wrong, but I could be right." *G*

Personally, I'm working on getting rid of the enclosure entirely, except for the low fq.  Not a new concept, but taking my own approach.

As for 'noise' cancellation, unless it's a reasonably steady source one would have to employ a means of inverting the incoming sound(s) at a matching db. Get Smart's Cone of Silence comes to my mind...

Even if it could be set up to be 'selective' as to what needs to be canceled, it would likely damp 'wanted' fq as well.  Speech would make anyone within the field being effected sound very strange IMHO.

Set That up on your porch for Halloween.  The kids would think they've arrived a Real haunted house... ;)  "Trick or Treat", indeed.