For Home Theaters - Gypsum Board, Ficem Board or Plywood?

Among other things, plywood by itself is almost certainly unapproved for use as interior wall sheathing by your local building code authorities. You would be ill-advised to use plywood as an interior wall sheathing material.

Light weight interior grade fiber cement board (aka cement fiberboard,) such as GP DensShield, USG DUROCK, etc., is usually intended as a lining or backing substrate (aka backerboard or underlayment) for special applications. As an adjunct to (acoustical) gypsum board it would be fine ... and under some circumstances may even beneficial.

Nevertheless, one of the best—and most commonly used—materials is one or two layers of 5/8-inch or thicker gypsum board. There are also several specialized acoustical grade gypsum board products available such as QuietRock® Soundproof Drywall. Initially such specialty products may be more expensive but in the long run they often turn out to be more cost-effective, when installed properly, than conventional approaches and materials.

In addition, you can further increase the effective sound transmission loss of any wall sheathing by installing resilient sound isolation clips and metal “hat channel” between the framing and the sheathing. Another approach, in addition to screws, is to use an adhesive compound such as Green Glue Noiseproofing Compound between the framing and the sheathing. (Green Glue also works great for bonding two conventional sheets of gypsum board together when installing dual layers of drywall.)

There are many effective techniques and methods when it comes to soundproofing and noise control. I recommend spending a sufficient amount of time researching and investigating various techniques, methods and materials to find those that best meet your needs and budget.

While you’re at it do not neglect the potential issues associated with flanking transmission while you’re in the design and planning phase. I’ve listed several resources below that should be helpful in your endeavor.

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National Gypsum Company

– [PDF] Gypsum Board Partitions - Steel Framing

http://www.nationalgypsum.com/resources/Selector/S...

– [PDF] Gypsum Board Partitions - Wood Framing

http://www.nationalgypsum.com/resources/Selector/W...

National Research Council Canada

– Sound Transmission Through Building Components

http://www.nrc-cnrc.gc.ca/eng/ibp/irc/bsi/85-sound...

– [PDF] Airborne Sound Transmission Through Walls and Floors

http://www.nrc-cnrc.gc.ca/obj/irc/doc/sound-transm...

– [PDF] Controlling Sound Transmission into Buildings

http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/bpn/56_...

– Indoor Environment Projects - Acoustics

http://www.nrc-cnrc.gc.ca/eng/programs/irc/ie/proj...

– Sound Transmission through Gypsum Board Walls - Phase I

(See internal reports IR-693 and IR-761)

http://www.nrc-cnrc.gc.ca/eng/projects/irc/gypsum-...

– Sound Transmission through Gypsum Board Walls - Phase II

(See internal report IR-832)

http://www.nrc-cnrc.gc.ca/eng/projects/irc/gypsum-...

Serious Materials Inc.

– QuietRock Soundproof Drywall

http://www.quietsolution.com/html/quietrock.html

– QuietRock® ES 5/8", Type X, Sound-Reducing Drywall

http://www.quietsolution.com/html/quietrock_es.htm...

– QuietRock® 545THX THX-Certified Soundproof Drywall

http://www.quietsolution.com/html/quietrock_thx.ht...

Gypsum Association

– Online Library

http://www.gypsum.org/download.html

– Technical Information for Architects, Engineers and Designers

http://gypsum.org/architects.html

American Fiber Cement Corporation

http://www.americanfibercement.com/

Kinetics Noise Control

– Kinetics Home Theater

http://www.kineticshometheater.com/

– Products and Systems

http://www.kineticsnoise.com/products.html

Green Glue Noiseproofing Compound

http://www.greengluecompany.com/

Soundproofing Made Simple

http://www.soundproofing101.com/

Super Soundproofing Discussion Forum

http://www.supersoundproofing.com/

[PDF] THX Architectural Suggestions

http://www.film-tech.com/warehouse/manuals/THXAS.p...

Audio, Video, Home Theaters and Acoustics

http://docs.google.com/View?id=dhpmqnbb_20f7j2qmhc

Densshield Vs Durock

If you coat it with glasss beads, it will be much brighter, similar to actual projector screens. I don't know the exact process to get an even coating of beads, but it can be extremely, incredibly messy to do yourself. I don't know if they are adhered using an adhesive or clear paint of some sort. I would think it is a clear urethane coating, as an adhesive would pick up dust really quickly.

it varies, if it's for a relatively light weight speaker, you can simply just screw it directly into the plaster board of the wall, however if that is not possible, you want a wood that resists vibration well and at the same time is easy to manage, MDF, and plyboard are excellent for this and will also provide a nice finish.