While preparing for a visit by some audiophile friends today, I noticed that the grillecloth covering the woofer of my HDTV had collected some dust.

It was easy enough to remove with a vacuum cleaner, but caused me to wonder if this effect could be purposefully harnessed to clean the local air of dust/debris.

Consider that a subwoofer pushes and pulls substantial amounts of air (will have to calculate this later.) Why not use this to advantage to clean out the fine particles of carpet, etc, etc. from the air?

Granted, the push-pull is symmetrical, but appropriate cloth material could easily be sticky for dust, while causing no decrease in fidelity.
-- csea, Feb 02 2008

On further consideration, perhaps electrostatic speakers (popular for some time in the 1970s - 80s) could also be combined with an electrostatic air cleaner, as the high voltage and air motion are present in both.
-- csea, Feb 02 2008


If anything, I would have thought that passing sound through the air will stir it up, making dust particles and the like take longer to settle.
-- DrCurry, Feb 02 2008


[DrCurry], I would have thought so, too, if I hadn't the experience of seeing a substantial buildup of dust on the woofer grille.

There must be some form of rectification going on, where dusty air is pulled in, and sticks to the cloth, but is not released on the outgoing flow.

I'm sorry now I didn't take a photo before I vacuumed.
-- csea, Feb 02 2008


Arrange for the electrostatics to work anti-phase with the sub, so the sub pushes out the dust, and the electrostatics attract it, then...I haven't thought this out very well, have I?
-- coprocephalous, Feb 02 2008


If you have central A/C you can witness this effect replicated by examining your air filter, which over time collects dust as air disturbed by the ultra-low-frequency rotary-monotone woofer passes through it.
-- Condiment, Feb 02 2008


OK for grins, let's assume a 15" subwoofer operating around 100 Hz, with a throw of 2 cm.

This gives a displacement of 1250 cm^3, and at 100 Hz, will displace ~0.125 m^3/second. Given that much of this will be "rebreathed" air, let's assume the local air currents are able to provide 10% "new" air.

If a normal living room / home theatre is about 3 x 4 x 5 m, or 72 m^3, a complete exchange should take place in 72 / 0.0125 = 5760 seconds, or 96 minutes, or about an hour and a half.

So your entire room air could be cleaned in the duration of Mahler's Second Symphony. Ymmv.
-- csea, Feb 10 2008



random, halfbakery