>Why not just use a synthetic "jelly" pad (like the ones used
>for wrist rests when operating a computer mouse)? A lot less
>heavy, and a great vibration damper.
Actually, no. The "jelly" pads tend to magnify vibration
instead of reducing. Think old Ford sedan with dead shocks.
The springs work, but there's no damping mechanism. Back in the
days when I worked in the electronics manufacturing realm we
tested this type of technology.
Real silica sand provides the best isolation. In recording
studios we've been known to float rooms on sand AND pour sand in
the walls. Twin double-studed walls with 1-2 layers of sheetrock
with sand inbetween.
The walls between studios looked like this:
1. Surface acoustical treatment
2. Plywood or sheetrock (depending on LF absorption issues)
3. Second layer of Plywood or sheetrock (depending on LF issues)
4. Split Studs (staggered one inch)
5. Fiberglass insulation between Studs
6. Sheetrock
7. Sand
8. Sheetrock
9. Fiberglass insulation between studs
10. Split Studs
11. One or Two layers of Plywood or Sheetrock (depending on LF)
12. Surface acoustical treatment.
We would cut the concrete floors between studios and made sure
that there was absolutely no mechanical connection between them.
One facility in Nashville has two-feet of poured concrete for
the floors. The mastering suites have the speakers mounted in
six-foot thick concrete walls.
Speaking of suspending... The old WXYZ studios in Detroit (where
the Lone Ranger, Sgt Preston, and the Green Hornet originated)
were suspended by piano wire. The entire rooms hung by wire and
had rubber bumpers on the sides.
In the RTE Studios (Dublin, Ireland), there is a soundstage for
broadcasting and recording orchestras that has an isolated pad
where the orchestra sits. Any microphone stands sit on the pad
and are isolated from the surrounding floor area.
The NPR studios in Washington DC are completely the opposite,
though. The building construction uses "post-tension"
construction. The floors are about as bouncy as a drum-head. You
can hear and feel it when somebody moves a file cabinet anywhere
in the building.
In San Francisco there is a pair of radio station studios
located on the upper floors of a downtown office building. Big
mistake. Every time the pumps, chillers or elevator motors kick
in the microphones swing and shake.
AG-Schnozz
__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|