generally, lower pitched sounds are harder to block than high pitched
ones. 60hz is a rather low pitch. if you're hearing a whining buzz,
it's much higher than 60hz, even if the sound is originating with
something to do with ac-dc.

there is an entire industry built on blocking out sound. check out
www.silentsource.com

for real heavy duty blocking, we're talking building a separate wall.
which isn't that extreme. you can become bob the builder for the
weekend and go crazy and build another wall or two. at minimum, you
can brick shut the window you are talking about. but if that's your
only source of ventilation, then you're screwed unless you install an
air feed in from somewhere.

light blocking:
studio foam, drapes, boarding up window

heavy duty:
walls within walls, thick massive stuff like bricks and thick
fiberglass insulation in walls. airspace between walls between walls.
float your floor off the ground and put it on special springs.

without knowing your situation, i'm guessing you need "medium
blockage". so you should build a fake wall in front of the one with
the window, leave a foot or two in between if you can, and stuff the
fake wall with fiberglass insulation, and drywall it. this is really
easy stuff if you don't have to deal with electrical stuff. you can
always run a power strip from the real wall if you need an outlet
there for some reason. if you need that window for ventilation, then
you can build a door to get to it for occasional survival air breaks.
or you could hook up a simple tubing to get to that window and rig up
some sort of blower system. not sure if that will affect the
possibility of someone breaking in if it's not secured properly into
the window frame.

anyway, it's late night. just some thoughts off the top of my head.

Pete Frose wrote:
What materials can absorp mostly the 60 or 120 Hz hum and is there a
contraption to null the noise in the room?

An NPR station that I once worked for had little choice
but to put their best studio in one of the noisiest locations
in the building. The room was located right beside the air
handling system for a 3 story building. They solved the
noise problem by installing a sheet of lead in the wall.
I don't know where someone would even *get* a sheet of lead
for this purpose, but the material they found worked very
well and they ended up with a nice quiet studio.

Chip
San Francisco, CA

Briarpatch wrote in message ...

I don't know where someone would even *get* a sheet of lead
for this purpose, but the material they found worked very
well and they ended up with a nice quiet studio.


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