weird; noise annoys

[CW]

"John Grossbohlin" wrote

So.... is it possible to develop noise cancelling sound for the shop? This along the lines of the noise cancelling systems in car audio systems?

***************************************** The short answer is yes. They have done it in small business type aircraft.

The thing is, the noise at each seat is different. You end up putting a microphone at each seat with its own canceling computer and speakers.

So, if you put 20 or 30 systems around the shop, you could help, a lot. You would also be much poorer.

If you want to help cut noise in the shop, you can also go for the sound absorbing approach. Brown builders board with burlap type material all over as much of the walls and ceiling you can manage. =============================================================== That and the mass amounts of sawdust it will hold should do a pretty good job. :)

[Morgans]

That and the mass amounts of sawdust it will hold should do a pretty good job. :)

********************************************** Yep. Kinda like what a big upper lip full of hair is good for; saving a little food for later!

Paper type egg cartons work pretty well, too. Not quite as much dust imbeds in them, but it does sit on them.

Acoustic ceiling tiles (drop in or other) works well, and doesn't collect as much.

-- Jim in NC

[John Grossbohlin]

With at least some hobbyist woodworkers in the same demographic as private jet owners there could be money to be made... ;~)

[Swingman]

That's certainly true, and if that is the case (which it most certainly is one of the components), then there should be a fairly specific frequency involved in the "siren/blow over a bottle" component of the overall sound, which lends itself even more to the additive/room acoustics theory ... particularly in light that the OP mentioned it was also noticeable in the living area above the shop.

A strong sine wave component added by your blade/air flow effect (with consistent air flow and blade rate) to the overall "noise" of both machines in the shop could certainly increase the overall SPL dramatically.

(I once recorded a "crystal bowl meditation" session for the wife of our local DA. She had a dozen different size crystal bowls that, when rubbed with her hands, would vibrate/resonate like wet wine glass rims, only much larger and louder. The additive effect (and standing wave generation) of these multiple bowls resonating in the room was enough to overdrive both the microphones, and the input of the console, to the point of necessitating strong compression be added to the chain, and could be heard, and felt, out in the parking lot ... virtually a "hands free" massage just being in the room. :) )

Safe to say there are a number of interacting components, both acoustic, mechanical, and environmental to the OP's phenomenon.

[clare]

Noise cancelling units to counteract the sound of air handling systems are quite common in offices. They are effective against relatively "constant mode" backround noise, and almost innefective against intermittent or varying noises.