[marcan_42]

It's a soundfield problem. This only works for wavelengths that are larger than the size of the emitters and the distance between them. And even then it only works well if you can get the emission pattern of your cancelling speaker exactly the same as the source.

So, assuming you had a magical beamforming speaker array around your circular saw, you'd still only be able to cancel frequencies around under 1kHz, because there's no way to get the thing in phase above that.

This is why noise-canceling earphones have much better active cancellation at high frequencies than headphones, which rely more on passive isolation until lower frequencies. They're smaller.