The purpose of the insulation is to provide lots of dead air spaces. The
smaller the spaces, the more likely to "eat" the sound waves rather than
allow them to pass through or transfer by medium vibration.

What insulates in heating/cooling applications is the air, not the fibers.

"Luigi Zanasi" wrote in message
...
On Wed, 16 Jul 2003 05:48:59 GMT, Steve Knight
scribbled

On Tue, 15 Jul 2003 09:46:58 -0700, Luigi Zanasi
wrote:

Ceiling:
Stuffed the cavity between the joists with fiberglass insulation (and
I mean stuffed, packed in tight)

this is a mistake. air space is the best thing you can have to help stop
sound.
dead air space is very effective.

Hi Steve,

I hate to disagree with you, but you might want to refer to any number
of research studies, reports and manuals on this issue, for example
from the Canada Mortgage and Housing Corporation (Kanuckistan's
equivalent to HUD):