"lbbs" wrote:
It's a question that I posted on many news groups, but no one
is willing to answer my actual question. It is a simple question. There
are two different ceiling tiles to choose from. One is light, flexible
and made fiber glass insulation. The other choice is a heavy tile, that is
hard (made out of asbestos or dry wall type of material, not sure though).
Which is better for sound insulation? Simple question right!!

I have asked a slew hard ware store to ask this very question and every
one a ask says the exact opposite. I have always heard that you need
mass and air space to have good sound insulation. My thinking is that
yes, hard objects carry sound, but since this ceiling is free floating and
supported only by wire, the sound will not travel through the hard tile.
Those that make sense.


PREVIOUS POST:
I was just wondering if I replace my flexible 48" x 24" ceiling tiles with
the hard type (much heavier) will I notice the difference in sound
proofing?

I call all kinds of hardware stores to see which of the two is better for
sound. The opinions are split 50/50 between flexible and hard type. I
personally think the hard type are better, I wonder if replacing them with
this type will actually make a noticeable difference to be worth replacing
them?


Well, depends on what you mean by "better". You can do two things with sound:
absorb it and reflect it. Reflection occurs when there is a large impedance
mismatch (i.e., soft to hard, as in air to hard surface), while absorption is a
bit trickier. Preferably, you do both, using reflection to keep the sound in
an area with lots of absorption, and using absorption to reduce the amount of
sound that needs to be reflected (no reflector is perfect, so the less that
needs to be reflected, the better).

Anyway, that's a long-winded intro into saying that the soft tiles are probably
better absorbers, but the hard tiles are better reflectors. Assuming you're
trying to keep sound that is generated in the room with the ceiling from
propagating to the rest of the house, the best approach would be to use the hard
tiles (or better, a "sandwich" of air/tile/air/tile) to keep the sound in the
room, and then some sort of wall hangings to absorb the sound. Depends on how
serious the problem is....you can throw a bucket at money at these things, if
you're so inclined.