Replacing room walls with MDF or Particle Board?

[Hybrid fourdoor]

Anyone ever replaced or upgraded their walls with MDF or particle board or similar? Does it help with sound dampening and lowering sounds from outside, or even outside hearing noises from the sound room?

We are going to have a house built this year, and the house has a large game room I want to use as a theater/entertainment room. I didn't know if using wood or somthing harder than sheetrock would be a good choice....since MDF is only like $15 for 4'x8' sheet (obviously need more than 1 though )

[Da5id4Vz]

Its tough to beet gyp board for cost and performance. If you want more mass/density double or triple up sheets of 3/8 and 5/8, stagger the seems, use construction adhesive in between layers, caulk at the top and bottom places. Need more isolation, stagger the studs between the inner and outer walls so they don’t make contact. Of course the cavity gets some dense fiber glass.

[sreten]

I agree with D5V,

plaster board is hard to beat and easier to work with.

The staggered studs sound an excellent idea, use different
thicknesses of plaster board on each wall section to stagger
the main resonances of the two sections.

sreten.

[FLZapped]

Originally posted by Hybrid fourdoor

We are going to have a house built this year, and the house has a large game room I want to use as a theater/entertainment room. I didn't know if using wood or somthing harder than sheetrock would be a good choice....since MDF is only like $15 for 4'x8' sheet (obviously need more than 1 though )

You certainly want to use a thicker stud plate, like 2x6 and stagger your 2x4 studs so that each wall surface is mounted on it's own set of studs. You'll want to weave fiberglass thoughout this arrangement before you seal it up.

Make sure you seal ALL openings for power, etc. Air leaks mean sound leaks. This means sealing your studplates at the floor so there are no leaks there, either. You might want to investigate the use of a gasket under them to help with this.

You could also stack your drywall over plywood to increase the wall density. The two different materials will have different resonances helping to reduce transmission through the wall. (Of course, if you take no mercy on your drywall man, you could specify 3/4" firebond)

One product I've wondered about, but never tried, is that concrete board used for tile backing in bathrooms. It's extremely hard and dense, but a bit thin. You'd probably need to put it over plywood.

Oh yeah, seal all your wallboard seams well too!

You'll probably want to look into a solid door, or even a fire rated door, which is usually heavy and dense. You'll need a good jamb seal and a floor seal.

If you're really serious, you'll also need to work on the AC ductwork that feeds the room. It will need to be a seperate feed and have a baffle in it somewhere. And if you're super serious, you might consider two seperate stud plates and set the room interior walls with various skews to help minimize room nodes.

A good book on all this is the Master Handbook of Acoustics by F. Alton Everest.

Having said all this, stopping high frequency energy is relatively easy, stopping bass takes mass and much more attention to detail.


-Bruce
(And then there is the ceiling...)

[SGregory]

Check your fire codes. Gypsum is considered as a fire break. There may be other materials for a fire break but gypsum board is the most standard. The fire break is required in my area.\Scott

[SimontY]

Hmm, I don't think anyone has mentioned this (sorry, I only skim-read it all)...

But if you don't need to trap in the sound, then building walls which are relatively transparent to the bass, will help in reducing the effects of room modes.

As we all know room modes are a pain in the **** for getting nice bass! So why try to keep it all in? Also, flexible walls will absorb some bass, which is probably a good thing, as long as the wall isn't so resonant that it is released with a big a delay and altered pitch.

It looks like you're (trying to write a letter (-just kidding)) trying to keep sound from getting out, so perhaps a thicker, solid outer wall, isolated from a slightly more flexible inner wall, which should absorb some bass, and lower the associated room modes.

Just some (daft?) ideas anyway!