Re: cheap-shit laser displays

On Fri, Jul 09, 2010 at 08:10:51AM -0700, Don Marti wrote:
> begin Kragen Javier Sitaker quotation of Fri, Jul 09, 2010 at 01:59:15AM -0400:
> > Presumably the lower-frequency vertical scan wouldn’t suffer from this
> > problem if it’s built out of the same mechanism.
> 
> >From the description, it sounds like this device
> would produce an audible 10khz whine and a 60Hz hum.
> Put it inside an evacuated capsule?

It surely would. You could diminish the problem by punching the speaker
membrane full of holes, which would be a lot easier than evacuating
something. The 60Hz hum would diminish fairly rapidly with distance
because of the small size of the cone; most of the energy will remain
localized around the cone instead of propagating as a wave. I think.

BTW, I'll fix the problem with kragen-discuss messages bouncing soon. At
the moment the milter is using an old static allowed-addresses list. I
need to fix it to pull the list from Mailman.

Kragen
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