Wall construction can make or break a high-end home theater renovation project. Poorly constructed walls, the wrong materials, and even the wrong choices in wall treatments can make the most expensive audio and video systems appear worse than old, secondhand systems. When drywalling a home theater, every element is essential, but there is help and guidance available.

Soundproofing Home Theaters

High-quality home theater systems often have noise levels of 100dB or more. These sound levels can be highly problematic for anyone trying to sleep in the next room. Therefore, you'll want a Sound Transmission Class (STC, a noise reduction level) of about 70 or higher and a Total Loss (TL, total loss at low frequencies) of 40dB, which is about twice the STC and TL of a standard wall.

Older soundproofing methods often included adding another layer of drywall, insulation, foam barriers, or installing mass-loaded vinyl beneath the drywall. Unfortunately, these construction methods only reduce sound by 2-9dB, which isn't nearly enough. Today, newer techniques use alternative construction methods to reduce sound levels by as much as 100dB.

Decoupled Wall Construction

One way to lessen sound from traveling into adjoining rooms is to create air cavities. So, if the room is quite large or has concrete walls, you might consider wall decoupling. With this method, you essentially build another wall in front of the existing one on an acoustic underlay. It's completely detached from the existing wall, and the space between the walls is loosely filled with insulation.

You can further increase the sound attenuation of a decoupled wall by installing resilient clips and channels. Here, you attach one side of a metal strip to the studs. Then, attach the drywall to the metal strip, which allows it to "float" while not touching the stud.

However, there are a few important things to remember:
  1. Don't allow the drywall to touch the ceiling or the floor, and
  2. Seal all the seams with soundproof caulking.
Otherwise, the sound will easily travel through the wall and remove most of the soundproofing benefits.

Sound Isolation Clips and Hat Channel Installation Techniques

Sound isolation clips are also a great alternative, provided the screws and studs don't touch. These are metal clips with a rubber washer-type gap between the screw and the stud. Next, a hat channel clips into the front of them.

A hat channel is an aluminum or stainless-steel strip that runs perpendicular to the wall studs. Then, the drywall is attached to make a 7/8" to 1-1/2" gap between the studs, screws, and the drywall. The result is a 35 to 70dB reduction depending on the materials and techniques you choose.

Staggered Stud Construction

Staggered stud construction may be a better option if the home theater is in a smaller room that lacks the space needed for decoupled construction. This building technique won't have as much soundproofing power as a decoupled wall, but it will still reduce the noise by 50-60dB.

Staggered stud works by using a wider sill plate and offsetting the studs to prevent them from touching both sides of the wall. Alternating between 2x4 and 2x6 studs, stagger them on the frame and use furring strips and sealant to ensure they don't touch the drywall on both sides. This method helps prevent the sound from transmitting through. Lastly, don't forget to use a soundproofing compound to seal everything off, including outlet boxes.

Drywalling for High-End Home Theaters

Standard drywall isn't going to cut it when it comes to soundproofing a home theater. You will need something specifically designed to deal with sound and the challenges of loud, low, persistent noise. There are several options on the market, however.

QuietRock or CertainTeed are quickly becoming a popular choice among drywallers. This variety is easy to install, quick, and keeps the mess down while acting as a dampening panel. But this drywall type does come at a higher cost.

What makes it effective? This drywall type has two layers of gypsum with a layer of viscoelastic sound-absorbing polymer to help stop the soundwaves from entering the wall. Some varieties of QuietRock include a quick-install style that installs like drywall but snaps into place. The reward, however, is up to 80 STC.

For a more affordable option, brands like National Gypsum have put out several varieties of soundproof drywall. It's moisture-resistant, mold-resistant, and has the viscoelastic dampening polymer in the middle. Their Soundbreak XP wallboard comes in 1/2" and 5/8", but the high-density gypsum shouldn't be a problem. It is still easy to cut, decorate, and work with.

If you do choose to use multiple layers of standard drywall, one on top of the other, you'll need a 0.5mm layer of damping compound between them. (You can skip this step if you're using resilient channels or another technique to create large gaps between the Gyproc.) However, you will still need to seal the joints with acoustic caulking regardless of which method you use.

Speakers, Audio, and Video Installations

If you've ever had to replace broken drywall because someone missed the stud while installing a speaker or projector, you'll already know why proper installation matters. And while, as a drywaller, you might not be installing a projector or speakers, understanding what the installation needs are can help avoid disaster.

The distance from the screen to the projector, called the throw distance, depends on the device's picture quality. And while some equipment like the Sony VPL-VW325ES Projector has excellent flexibility and fine-tuning due to its motorized zoom and lens-shift range, not all units will have this ability. Therefore, the installation might require some patience and some good, old-fashioned trial and error.

The throw distance for the Sony VPL-VW325ES, for example, is 91" to 187" for an 80" screen and up to 231" to 472" for a 200" screen. The manual includes a helpful guide to help with measurements. But don't forget that projectors come with remotes, so you'll need to make sure it's accessible and the signal isn't blocked.

How to install a projector will depend on the mount type. Generally, there are two types of projector mounts:

Ceiling mounts depend on what type of ceiling the room has. Vaulted ceilings, for example, will require special vaulted ceiling adapters that have a telescoping pole to adjust the height. There are also adaptors for hung ceilings since the framework can't support much weight. (Some projectors require proprietary mounts, but most work with a universal support.)

Wall mounts are the second type available for smaller rooms. Some wall mounts have a broad base, but others have an extendable arm that allows you to pull out the projector up to 4' from the wall. However, it's essential to make sure the mount is strong enough to handle the projector's weight and won't get in the way. These types will require some coordination to find the right location.

And while it goes without saying that projector and speaker installation will require having studs or supports in the right places, it's helpful to double-check before you start sealing everything up. However, you may need to have custom metal or wood brackets made if it's too late. Just check it to make sure they don't vibrate and are wide enough to work with the chosen mounts since some of these can have a wide base or set of "feet."

Getting Drywall Help

Drywall is a vital step in any home theater renovation. If you've never done a high-end home theater before, and you are unsure of what you need to do, don't be afraid to reach out. Many expert drywallers here can offer advice or help you solve any tricky problem you might face. And if you're eager to try some of the new soundproofing drywall on the market, don't be afraid to contact the manufacturer. They have all sorts of resources and experts available to help you make the right choice for your next big drywall project.

Sponsored by: Sony