One extremely effective way to absorb sound in a home theater is carpeting. A thick Berber with standard padding underneath is a good choice. If you have hardwood or tile floors, lay down an area rug to absorb sound.
Lighting is also crucial to the overall quality of a home theater. The room should be dark, much like a movie theater but with just enough illumination so people can move around safely. Arrange the light sources so they don't cast any glare on the big screen. Directivity of the lighting is important. For example, track lighting, where you can aim and focus the light, works beautifully.
Avoid table lamps and fluorescents because they will flood the room with light and cast a glare on the screen. Use directional lighting instead.
One of the most important things is to install dimmers – they are an inexpensive way to adjust the level of light in a home theater.
Thick draperies can block out most of the light from windows, but specialty manufacturers make motorized shades and drapes. They cost more than standard fabric draperies and most require professional installation, but they're designed to completely block outside light.
Furniture for Your Home Theater
When it comes to furniture for a home theater, you can find expensive, high-quality cabinets to house gear. For the DIYer on a budget, equipment cabinets don't have to be made of expensive wood or have a fine finish.
For the DIY project home theater, build a simple plywood cabinet to go under the screen to house the subwoofers. Place a hinged door frame covered with acoustic fabric on the front of the cabinet so sound can pass through. Paint the cabinet black.
If you can, place the receiver, DVD player and other gear in another room. By being in another room, it cuts down on acoustic interference from cooling fans and other sounds from the equipment.
Media storage cabinets are best placed in the back of the room. They'll be out of sight from the viewing positions and also double as acoustic absorbers for sound waves bouncing around the back of the room.
Walls and Doors
The color of the room can also help reduce screen glare. When it comes to the walls and ceiling, the goal is to not use anything that would distract from the room's focal point – the screen.
Cover walls with acoustic fabric, like in movie theaters.
Paint the home theater a dark color, but don't use a gloss, semi-gloss or satin finish paint. Use a flat, no-glare paint.
The door is the weakest link in sound transmission. Standard-grade interior doors can let sound filter into other parts of the house via gaps between the door and walls.
Pocket doors can also let a lot of sound leak through. If you do have one, you may have to add special sound-isolation material.