Home Theater Audio: Tips, Advice and FAQs
Experts from DIY Network's hit show Hollywood Hi-Tech provide insight on how to set up the audio system in a home theater or media room.
Home Theater Audio Basics
Movies are recorded so that the audience hears noises all around, which makes you feel like you are a part of the movie. That is why you have multiple speakers in a surround-sound system: Each speaker in a surround-sound system is assigned different sounds.
Whenever possible, use a complete sound system from a single manufacturer. The sound quality of speakers can vary a lot, even between speakers from different lines from the same manufacturer. Always try to get speakers that were designed to be used together.
Get the biggest and best quality speakers your budget can afford. Inexpensive "home theater in a box" systems with small cube or desktop speakers are fine for home offices, dorm rooms, etc., but they can't produce the volume or sound quality needed for a home theater environment.
In-wall and ceiling models are fine for surround speakers since most of the music and almost all of the dialogue in a movie comes from the front speakers, with the surround speakers used mainly for sound effects.
Most home theater speaker systems are either 5.1 or 7.1 channels. The five main speakers in a 5.1 system are the front left, center and right (LCR) and the two back surround speakers. The ".1" is the subwoofer, which produces the deep bass. A 7.1 system adds two rear surround speakers.
What exactly are woofers and tweeters? A tweeter is for high-frequency sounds and woofers are for low-frequency sounds. A tweeter ranges from 200 to 20,000 hertz, which is the upper limit of human hearing. The name comes from the high-pitched noise that birds make. Good quality in-dome tweeters should be lightweight, high stiffness and damping materials. A woofer is usually the largest cone inside the speaker. Subwoofers range from 10 to 120 hertz. They should also be made of lightweight yet stiff material. The name comes from the sound of a dog's "woof."
Setting Up Audio Components
When setting up your home theater, avoid using a room where the walls are all the same length. Place your screen and front speakers on one of the narrow walls so that the speakers fire along the long walls of the room.
The back-surround speakers should be mounted on the side walls just behind the main listening position, at about five to six feet off the floor. The rear-surround speakers should be mounted about two feet apart on the back wall of the room and placed at the same height as the back surrounds.
In general, freestanding speakers sound best. Wall-mounted speakers are a close second, while built-in wall speakers rank third. Only use ceiling speakers for the front channels if you have no other choice.
Make sure to hook up your speakers in phase, meaning whatever wire is attached to the red terminal at the receiver should be attached to the red terminal on the speaker; the same applies to the black terminals. Otherwise, your speakers will sound thin and diffuse.
Unless you have large front speakers with big, powerful bass drivers, you'll need at least one subwoofer to create the low bass. Subwoofers usually sound best when placed in a corner of the room, but experiment until you find a position that creates strong bass that isn't rumbly or boomy.
In larger rooms (at least 20' x 14'), it often helps to have at least one more subwoofer. The second subwoofer usually sounds best in the corner farthest from the one where the first subwoofer is located. Experiment until you find the best position.
Tips for Running Audio Cables
For the best sound quality, keep cable runs as short as possible.
Use at least 14-gauge speaker cable. (The lower the number, the thicker the cable.) For runs of 50 feet or longer, use at least 12-gauge cable.
Cables with metal connectors make a more secure connection with the speaker than ones with bare-wire ends, resulting in better sound. Most inexpensive speakers have spring-clip terminals, which are designed to be used with bare wire. But even spring clips will accept cables with pin connectors.
If you have multiple cables running next to each other from your receiver to your speakers, consider buying a sleeve from a company like Monster Cable to give them a neater appearance. The sleeve bundles the cables together, making them easier to route and manage.
If you have basic carpentry skills, consider running the cables behind your baseboards and under your door sills. (Make sure to use wire rated for in-wall use.) Most home and electrical supply stores sell wall plates for feeding cables through the baseboard.
Information courtesy of Roberts Home Audio and Video.