Designing and setting up a home theater

Long lines and loud crowds can ruin any movie. However, you can escape those cinematic distractions by bringing high-quality movie theater ambience into your living room. By using the proper equipment and installation techniques to set up your own home theater system, you can achieve earth-shattering sounds and a vivid viewing experience every time you press the On button.

The All-Important Receiver

The selection of a high-quality receiver—the piece of equipment that brings together all elements of your home theater system—is a crucial decision. When you buy a receiver, make sure the unit contains the proper input and output jacks to connect all elements of the system you've decided to install, as Figure 1 shows. The receiver's available input and output jacks will dictate components that you can include in your home theater. Generally, receivers have four audio-only input jacks (including RCA connections for analog signals, digital coaxial connections for digital audio, and optical—i.e., fiber-optic—input jacks for digital audio signals), five audio and video input jacks, speaker output jacks, line-level output jacks, and a video monitor output jack. In addition, many high-end receivers have S-Video and component video input and output jacks.

The various inputs give you flexibility when connecting equipment; some technologies provide better quality than others. For example, optical input provides a high-quality signal from the source device (e.g., DVD player, CD player) to the receiver because optical signals aren't susceptible to interference from electrical signals. Your system components will dictate, by virtue of the outputs on the back of each device, which type of connection to use.

You can buy a receiver (aka tuner) that's integrated with the amplifier, or you can purchase the amplifier as a standalone component. Separate units give you more flexibility when you design a system and allow for easier upgrades. After you decide how much you want to spend on your system, you can more easily decide whether to buy separate or integrated components. Basic components of your home theater system include a TV or video monitor, an audio CD player, a DVD player, and possibly a tape deck and VCR.

More Component Options


For receiving video signals into your home theater, a satellite receiver offers twice the picture resolution of a standard analog video signal; satellite also offers digital video and audio. If you buy a satellite receiver with Dolby Laboratories' Dolby Digital output, you'll pay $200 to $300 more than you would for a standard Digital Satellite System (DSS). Most advertised bargains for satellites carry only an analog Dolby Surround Pro Logic signal.

Some of the newer and more innovative devices available for your home theater system are MP3 and digital audio players and recorders and MPEG2 digital video players and recorders. Examples of digital video recorders are TiVo, ReplayTV, and WebTV Networks' UltimateTV. These devices let you record digital audio and video to a hard disk. Additionally, these devices let you share this stored media throughout your home.

Sound Formats


Sound signals on audio CDs, videotapes, and DVDs are embedded in the media. These signals travel to the receiver, which decodes them and sends them to the proper speakers in the proper format. Usually, different modes are available on each source disk or tape, and each kind of surround sound system specializes in one of those formats.

When purchasing or upgrading a home theater system, you'll need to consider the various kinds of sound systems that are available. The basic surround sound format begins with analog Dolby Surround. The next step up, also an analog format, is Pro Logic. After Pro Logic, surround sound moves into the digital domain with Dolby Digital 5.1 and the top-of-the-line 6.1 Dolby Digital Surround EX format. Dolby's competition, Digital Theater Systems (DTS), offers the digital formats DTS-ES 6.1 and DTS 5.1. Most receivers offer Pro Logic and Dolby Digital capabilities, and higher-end receivers also offer DTS.

Speaker Selection


Your choice of the type and number of speakers depends largely on the sound format you select for your system. Basic surround sound typically requires a left front speaker, a right front speaker, and two mono rear speakers. Pro Logic requires the basic surround sound speakers and a center-channel speaker. The Dolby Digital 6.1 and Dolby Digital 5.1 formats require a subwoofer and two supplementary side-channel speakers. Specifically, Dolby Digital 5.1 systems use five speakers and one subwoofer, and Dolby Digital 6.1 systems use six speakers and one subwoofer.

A crucial part of your speaker system is the subwoofer, which produces low-frequency sounds for your theater. The sound travels equally in all directions and can pass through walls or floors. Subwoofer placement is an important facet of your theater because you can use the walls and floor to adjust the amount of "boom" your system generates. Subwoofers are either powered (i.e., the speaker plugs into a standard 110-volt outlet and is powered by an internal amplifier inside the cabinet) or passive (i.e., the speaker's power comes from the receiver).

Good Vibrations


After you choose the products you want to install, you can now set up the room, system, and speakers. A crucial step in obtaining a high-quality theater sound and feel is to determine the room's acoustics.

You can significantly adjust the room's acoustics by using a suitable equalizer and a sound-measuring device. For example, you can use a one-third octave graphic equalizer and a Real-Time Analyzer (RTA). The RTA measures and displays the room's sound absorption and reflection so that you can properly adjust the gain of each frequency on the equalizer.

Cabinets and Components


Some homeowners use custom-built cabinets to hold their entertainment centers. Adjustable shelving lets you make future improvements to your system and upgrade equipment. Avoid white as the cabinet's interior color; white can make infrared (IR) signals from remote control systems bounce around inside the cabinet, thus causing erratic behavior of equipment. You also need to avoid using solid doors on the equipment cabinet. Solid doors can trap heat inside the cabinet, which can damage your equipment. A wooden cabinet frame with an acoustic screen as a cover allows some ventilation. A fan or air-conditioning intake in the cabinet can also help keep the cabinet interior cool.

Place each piece of equipment on a separate shelf instead of stacking multiple components on each other. This arrangement will help prevent heat buildup. If you're using a standalone amplifier, place it on the lowest shelf; amplifier units are typically quite heavy. Adding support braces under each shelf can ensure that the shelves will support heavy pieces of equipment.

Your system will need sufficient electrical power to operate, and your home theater can place a huge load on household circuits. Consider installing a UPS, offering both power backup and surge protection, which can save you time in reprogramming equipment after a power failure.

In many home theaters, the TV is some distance from the rest of the audio and video equipment. (A tip for determining proper TV screen size for your home theater is that viewing distance should be three to five times the diagonal measurement of the screen. For example, if your favorite chair is 10' to 15' from the screen, a 36" TV screen is ideal for your needs.) In this case, you need to run the necessary wiring between the receiver and the TV. Usually, a dual run of RG6 quad shield coaxial cable; a run of Category 5—rated computer network wire; one 16-gauge, 2-conductor (i.e., 16/2) cable for the center channel; and one 22/4 cable (for future additions to your system) will suffice. The Cat 5 wire, which has eight 24-gauge wires, can let the system send multiple IR video signals and sense the initial state of the television as "on" or "off."

When your system uses digital signals, all audio and video components need to connect directly to the receiver with component cables or optical connections. Your system also needs one cable from the receiver's video output to the TV. These connections let you simply press a button on a remote control unit to change the audio and video outputs. For example, when you press the DVD button on the remote control, the receiver switches to DVD mode, sending DVD audio to the speakers, accepting video input from the DVD player, and sending the video signal to the TV.

Connecting and Placing Speakers


To connect speakers to the receiver, use wire between 16 gauge and 12 gauge. The larger gauge (i.e., 12-gauge) is best for longer runs. Typically, a 16-gauge cable will be sufficient for most home theaters.

Proper speaker positioning in your home theater is crucial to achieving the best sound quality. Front speakers should point toward listeners, with the front left, front right, and front center speakers on the same horizontal plane, if possible. The rear speakers should be off axis (i.e., not pointed directly at the listening position). If you're creating a seven-channel system, which Figure 2 shows, position the front-effect speakers (i.e., side speakers) to the front of the listener on both sides.

For optimum bass response, place the subwoofer in a rear corner. You can place the subwoofer closer to or farther away from the corner to adjust the "boom" of the low frequencies, and you can set some subwoofer models on spikes to isolate the speaker from the floor, thus tightening the bass. Don't place the subwoofer in a cabinet because low-frequency vibration can rattle the cabinets and doors, producing undesirable sounds.

An important aspect of setting up the system is balancing the sound between front speakers, center speakers, rear speakers, and the subwoofer. Using a Sound Pressure Level (SPL) meter, a highly technical process that's best handled by an experienced professional, will greatly improve the listening experience.

Control and Interfacing


IR remote controls are the most basic and well-known way to control and interact with a home theater system. Instead of maintaining an arsenal of remote control units for each system component, buy a universal remote control, preferably a model that can learn unknown IR codes. An example is Universal Remote Control's Home Theater Master SL-9000.

The next evolution in control is the IR remote with a small black-and-white touchscreen. The touchscreen UI is easier to see and operate than a standard button remote. An example of a touchscreen remote is Philips's Pronto. These units require more programming than remotes with buttons, and some use PC software for programming. Another option is the wireless radio frequency (RF) color touchscreen. Examples of this type of product are Crestron Electronics' ST-1550C Wireless Touchpanel and AMX's CP4 Color Touch Panel. These units can use icons for various TV channels, such as A&E and ESPN. RF remotes let you control the audio system from any room in your home. Such systems generally demand a dedicated processor, such as Crestron's CNMSX-AV or CNMSX-PRO control system, and require extensive programming but allow the fastest and easiest operation of your home theater.

Some remote controls, including the models I've mentioned, offer macro capabilities, which let you build several functions into one button. For example, you can program the DVD button to set the receiver to accept DVD input and to output DVD video to the TV. By pressing another button, you can turn everything off. Without macro capabilities, a remote lets you complete only one step with each press of the button.

When one component of your system gets out of sync with the others, your remotes won't work properly. The typical result of such a problem is that when you turn the system on by remote control, half of the equipment turns on and half turns off. The remedy is to buy a standalone control system that has a state-sensing device, such as a current detector or video sensor. The sensors plug into an output on each piece of equipment and tell the control system whether a component is on or off. The programmed control unit ensures that the system components work together.

An example of such a control system is the CNMSX-AV integrated control system. With this system, a programmer can design macros that sense each component's initial state and change settings accordingly. Typically, control systems can control many other devices in addition to audio and video, such as drapes, lights, and air conditioning. Integrated systems give you more versatility and control than other types of control systems, and they have room for upgrades and add-ons.

Integrated systems can bring high-quality cinema to the comfort of your home. When your home theater is fully outfitted and integrated, you can program one button to start the entire movie-viewing experience. Simply touch the button, and the control system will switch on the TV, DVD player, and receiver; set the proper modes and sound; close the drapes; adjust the air; and dim the lights. The only things missing are long lines and talkative neighbors.