Will isolated sheets of fiberboard help reduce sound?

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As far as I know...

Yes, you need mass, but it needs to be uninteruppted mass. Think of a boat -
if you have a leak, the water gets through. Even a small hole can reduce the
effectiveness of a wall by 6dB or more. I used plywood in my walls and ceiling
and it worked fine - but I didn't have holes. I would expect fiberboard to
work in a similar way.

Absorbent sheets, such as rigid fiberglass (Owens Corning 703 or 705) will help
to absorb reflections which will reduce the transmitted sound a little, but the
openings will still dominate by far. They will typically help it sound better
*inside* the room, depending on how they are used.

In the same way, heavy moving blankets suspended from the ceiling and covering
the walls will cut some of the sound down - but the bass frequencies in
particular are a real pain to handle.

-lee-

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Hellen,

> If I cover the windows and interior walls with, say, 8'x4', 1" sheets of
high density fiberboard <

Lee nailed it. If you have even a tiny leak that will negate any benefit
from adding mass. If the problem is mainly at the windows, which makes
sense, then just focus on covering the windows and forget the walls. Use 3/4
inch MDF or equivalent, cut a few inches larger all around than the window
size, and put it over the windows. You'll need caulk or equivalent to seal
it to the walls air tight.

--Ethan

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>There will be gaps above the boards (10 ft. ceiling) and the
>entirety of each wall will not be covered. Perhaps 70% of the walls can be
>covered with the fiberboard sheets.

Then don't bother. I can tell you from experience that unless you do
everything in your power to maintain an airtight fit you'll be wasting time,
materials, and money.



Joe Egan
EMP
Colchester, VT
www.eganmedia.com

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>From: "Ethan Winer" ethanwat

>Lee nailed it. If you have even a tiny leak that will negate any benefit
>from adding mass.

Does that mean that with "leaks" (ie, less than 100% coverage, or in
my case, perhaps 70% of an interior wall covered with MDF board), there will
basically be no sound reduction at all?
Or will there be "some" impact, just not nearly as much as 100% coverage?

I'm just looking for some sound reduction. If covering 70% or so of
the walls with some very dense board (a la MDF) will provide some reduction,
I'll probably try it. If it will provide next to no reduction, then obviously
I'd be wasting time and money.
Thanks!

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Hellen,

> Does that mean that with "leaks" (ie, less than 100% coverage <

I meant actual leaks, like openings. Then cover the glass with MDF or sheet
rock, because glass passes more sound than sheet rock walls. Once the
windows are covered, then you can look into beefing up the walls. For that
you can just use more layers of sheet rock.

--Ethan

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On Mon, 13 Sep 2004 04:02:16 -0400, Hellenason7 wrote
(in article <20040913040216.03847.00000473@mb-m10.aol.com>):

>> From: "Ethan Winer" ethanwat
>
>> Lee nailed it. If you have even a tiny leak that will negate any benefit
>> from adding mass.
>
> Does that mean that with "leaks" (ie, less than 100% coverage, or
> in
> my case, perhaps 70% of an interior wall covered with MDF board), there will
> basically be no sound reduction at all?
> Or will there be "some" impact, just not nearly as much as 100% coverage?
>
> I'm just looking for some sound reduction. If covering 70% or so of
> the walls with some very dense board (a la MDF) will provide some reduction,
> I'll probably try it. If it will provide next to no reduction, then
obviously
> I'd be wasting time and money.
> Thanks!

It ain't the covering. It's the combination of isolation and covering. Like
peanut butter and jelly; if you don't have both, it ain't a sandwich.

Ty Ford



-- Ty Ford's equipment reviews, audio samples, rates and other audiocentric
stuff are at www.tyford.com

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hellenason7@aol.com (Hellenason7) wrote in message news:<20040913040216.03847.00000473@mb-m10.aol.com>...
> >From: "Ethan Winer" ethanwat
>
> >Lee nailed it. If you have even a tiny leak that will negate any benefit
> >from adding mass.
>
> Does that mean that with "leaks" (ie, less than 100% coverage, or in
> my case, perhaps 70% of an interior wall covered with MDF board), there will
> basically be no sound reduction at all?
> Or will there be "some" impact, just not nearly as much as 100% coverage?
>
> I'm just looking for some sound reduction. If covering 70% or so of
> the walls with some very dense board (a la MDF) will provide some reduction,
> I'll probably try it. If it will provide next to no reduction, then obviously
> I'd be wasting time and money.
> Thanks!

Covering 70% of the walls might give you 10-20% reduction in
transmitted sound. Not worth it. Your OP mentioned windows and guitar
cabs. Spend your money on sealing up the windows as tight as possible,
making a 2nd barrier (insulated shutters) for the windows, and
building an iso cabinet for the amp. Maybe an iso room for the drums,
too.

Mikey Wozniak
Nova Music Productions
This sig is haiku

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<< If covering 70% or so of
the walls with some very dense board (a la MDF) will provide some reduction,
I'll probably try it. If it will provide next to no reduction, then obviously
I'd be wasting time and money. >>

With only 70% coverage of the offending sound leak, you will basically
accomplish no discernable improvement in sound transmission. It really does
need to be an airtight seal to get real results.

Scott Fraser

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I don't know the numbers, but offhand Mikey's numbers (10-20% reduction) sound
about right.

Another option, especially if you are able to wear headphones for the guitar
would be a PODxt from Line6 to cut that part of the sound down. The drums,
especially the kick, are still the killer. Of course, there's always Vdrums
for that too.....

-lee-

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hellenason7@aol.com (Hellenason7) wrote in message news:<20040911173914.01927.00000458@mb-m23.aol.com>...
> The sound leakage from my basement is okay in terms of not disturbing
> neighbors "too much," but I'd still like to reduce it further so that I can
> record later into the evening.
> Most of the sound seems to escape from window locations. I'm talking
> mainly about bass drum and toms, but also my guitar amp.
>
> I know you need mass to reduce sound. If I cover the windows and interior
> walls with, say, 8'x4', 1" sheets of high density fiberboard (compressed
> sawdust), will I get any appreciable reduction of sound through the
> windows/walls? There will be gaps above the boards (10 ft. ceiling) and the
> entirety of each wall will not be covered. Perhaps 70% of the walls can be
> covered with the fiberboard sheets. Would there be a better choice than the
> fiberboard? Heavy fiberglass sheets, perhaps?
> Thanks!

I had the same problem with windows, and I built "plugs" out of 2"
Johns Manville I/S 600 (equivalent to 703) and luan board. I covered
it with basic cotton cloth from Walmart, and stick the luan towards
the window, with the insulation towards the room. I also have
shutters I can close over that to really tighten things up.

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On or about 11 Sep 2004 23:32:38 GMT, Leoaw3 allegedly wrote:

> Yes, you need mass, but it needs to be uninteruppted mass. Think of a boat -
> if you have a leak, the water gets through.

That's not a bad analogy. Where there is an air gap, there is a hole for
the pressure difference (sound) to squirt through.


Noel Bachelor noelbachelorAT(From:_domain)
Language Recordings Inc (Darwin Australia)