Home Theater 101What Is Home Theater?Home theater is the combination of big-screen television and surround sound. That is the shortest definition, though not the only one. Home theater can refer to an entertainment system including a large high-definition video display, a surround sound system, and source components. It can also refer to a room dedicated to such a system. Some audiophiles use the term home theater to distinguish between surround and two-channel audio systems. And the term is used to market a wide variety of audio and video products. On the video side, home theater products may include flat-screen TVs, rear-projection TVs, and front-projection video systems with separate screens. Direct-view TVs, the kind with a single large picture tube, are generally not large enough for home theater use though other display technologies, especially new kinds of flat panels, may emerge in the future. On the audio side, home theater products may include speakers of many sizes and types—towers, monitors, satellite/subwoofer sets, left/center/right speakers, bipole/dipole surrounds, bar-type speakers, in-wall speakers, on-wall speakers—as well as the audio/video receivers and other components that power them. Signal sources—the content that is played through these devices—for home theater are those that provide both digital TV and surround sound, most notably Blu-ray and DVD players, but also including DVRs, antennas, and set-top boxes provided by cable, satellite, and telco. High-definition sources are preferable. There are also "home theater in a box" systems that consolidate what would otherwise be separate purchases into compact packages that are easy to set up and use. This array of products may seem bewildering. But if you're interested in home theater, it's safe to say that you love movies, television, and/or music, and you're interested in finding the best way to fit them—comfortably and practically—into your own home. This primer will help you sort through the available options. Big-Screen TelevisionThe video display in a home theater system should be big enough to pull you out of real life and immerse you in a movie, TV program, sporting event, or video game. What Is the Right Display Size? Display size and viewing distance are interrelated, but in most rooms, viewing distance is fixed, so screen size is the variable you need to consider. Measure the viewing distance from seating area to screen surface, then take your tape measure to the store and find something that looks good at that distance. You want as big a display as you can get without the pixels—the dots that form the picture—becoming visible to a person with good eyesight. What Is the Right Display Type? Flat-panel HDTVs have captured everyone's imagination. LCDs (liquid crystal displays) are the most common choice. They are available in a broad range of sizes, offer an array of Energy Star-rated models, and are the lightest and easiest televisions to mount. Possible drawbacks include limited viewing angle, greyish black-level reproduction, and motion smear. Plasmas tend to have better black level and less motion smear, though their size range is more limited than LCD, they can use more energy, and can be heavier and harder to mount. For value, consider a rear-projection set. Though shrinking, this category offers the most screen inches per buck. Its main drawback is lack of brightness uniformity at the corners. For maximum picture size, consider a front-projection system with separate screen, as long as you can use it in a darkened room. Shopping Tip: HDTVs with resolution of 720p (720 x 1280 pixels) provide good value in screen sizes under 40 inches. While they have less resolution than 1080p (1080 x 1920 pixels), your eyes can't tell the difference at smaller screen sizes. Note, however, that 1080p source material, such as Blu-ray, will have to be downconverted to 720p, and you may see conversion artifacts. For screen sizes of 40 inches and up, get a 1080p set. Surround SoundThe audio part of a home theater system should surround you with sound, literally amplifying the impact of what's happening onscreen. It is also highly desirable for the system to perform to audiophile standards, making the musical experience as powerful as the cinematic one. What System Architecture Fits Your Needs? Most home theater systems are built around an audio/video receiver, which provides source switching, surround decoding, and five-to-seven channels of amplification. However, to fill larger rooms, or to obtain better performance, some audiophiles prefer to split the receiver's functions into a multi-channel power amplifier and separate preamp-processor. In smaller rooms, people prefer simpler in-a-box systems or sound-bar speakers that mount below a flat-panel TV. In any case, a true surround system has 5.1 to 7.1 channels: three in front, two on the side walls, and optionally, two more on the rear walls, plus a self-powered subwoofer. What Surround Technologies Do You Need? Surround technologies are a complex subject, but they can be loosely grouped into three generations. First-generation surround formats include Dolby Surround and Dolby Pro Logic, which extract surround signals from the stereo soundtracks of videotapes and other legacy sources. The second-generation formats, Dolby Digital and DTS 5.1, arrived with DVD and DTV broadcasting. Their 6.1/7.1-channel versions are Dolby Digital EX and DTS-ES. The third-generation surround formats are Dolby TrueHD, Dolby Digital Plus, DTS-HD Master Audio, and DTS-HD High Resolution Audio. They are included in some Blu-ray disc releases. Dolby TrueHD and DTS-HD Master Audio are state-of-the-art lossless formats which provide the home listener with a signal identical in quality to that heard by the mastering engineer. Dolby Digital Plus and DTS-HD High Resolution Audio offer more modest improvements over Dolby Digital and DTS, though they are not as good as the lossless formats. Shopping Tip: It's desirable for receivers and Blu-ray players to include surround decoding for all of these formats and to pass the bitstream from player to receiver via HDMI—get version 1.3 to cover all the surround formats listed above. However, to provide compatibility with entry-level or older receivers, surround formats (including Dolby TrueHD and DTS-HD Master Audio) can be decoded within a Blu-ray player and passed to the receiver as high-res PCM signals (via HDMI) or analog signals (via the multi-channel analog interface), so it is not absolutely necessary for the receiver to decode all of them. Signal SourcesFor a home theater system to perform well, it must be fed video and audio signals of the highest quality. That means HDTV and surround sound in the best possible format available for a given piece of material. Does HDTV Make a Difference? In screen sizes of 27 inches and up, high-definition television provides a discernibly sharper picture, usually in widescreen proportions of 16:9, or about a third wider than now-obsolete 4:3 sets. HDTV enables you to see more detail in movies and sporting events—not only in long shots, but also in close-up shots. And the wider 16:9 aspect ratio gives a wider perspective to still shots, as well as greater sweep to Hail Mary passes and other onscreen motion. What Are the High-Def Signal Sources? The two best sources of HDTV are the Blu-ray disc format and over-the-air ATSC broadcasts, both of which support not only HD resolution but extremely high data rates, ensuring a more artifact-free picture with less blocky pixellation and other forms of video distortion. DVD is a standard-definition format, which means it has lower resolution than HDTV. Cable and satellite operators provide some HDTV channels, but due to bandwidth constraints, they provide it at lower data rates, which often don't match the quality of a good antenna-delivered picture. To get the latest lossless surround formats, Dolby TrueHD and DTS-HD Master Audio, Blu-ray is currently the best option. Shopping Tip: When buying a Blu-ray player, get the last profile to obtain the latest interactive features. Currently the highest level is Profile 2.0, BD-Live. AccessoriesA few pragmatically chosen accessories will help get the best possible performance out of your investment in a home theater system. Mounting: Wall mounting is a great space saver. It enables you to enjoy big picture and big sound without dominating the room or hogging floor space. And it can work both for flat-panel displays and some speakers, such as compact satellite, on-wall, and bar speakers. This may be a job for a professional. If you go it alone, any mount should be rated for the weight of what it holds plus, to be safe, another 50 percent. Heavier objects will require that you penetrate the wooden stud behind the wall. Speakers may have threaded inserts that need to be matched to mounting hardware, though smaller ones may have simpler keyhole mounts. Tilting mounts can be a big help for aiming speakers at the seating position. Furniture: The bulky armoire-like a/v cabinetry of yesteryear is passing into obsolescence along with the direct-view TV. If you don't want to wall-mount your flat-panel HDTV, consider a low credenza, with space for speakers on either side, and a center-channel speaker on the shelf below, and more space for a few key components such as your Blu-ray player and cable box. Speakers will sound their best on stands a few feet from the wall. Stands can rest on spikes to couple them to the floor, clarifying the bass. One of the attractions of small satellite speakers is that their stands can be slender rods, which intrude less into a tastefully decorated room. Cables: Speaker cables should usually be at least 16-gauge (or AWG) in thickness or more—the lower the number, the thicker they are—especially for long runs. Some of the smallest satellite speakers are designed for thinner cable. Bare wire tips provide a good connection but the exposed copper corrodes over time. For protection against corrosion, speaker cables may be terminated in spade lugs, banana plugs, pins, or soldered tips, depending on what the speaker allows. Premium cables can offer better insulation and other design features, and may offer better performance, especially speaker cables and analog interconnects. However, your investment in cable should not approach the total cost of your system. Very expensive cables should be auditioned with care. Power Line Accessories: Cheap power strips should be avoided—for safety reasons, and because your equipment deserves better. At least use a surge suppressor to protect your system from power spikes. A good one will indicate whether the outlet is correctly polarized and grounded. Better yet, consider a power-line conditioner. A good one will filter out radio-frequency and electromagnetic interference and isolate components from one another. A relatively new category is the voltage stabilizer, which ensures that your gear receives a steady 120 volts when the power supply is sagging. To determine whether you need a voltage stabilizer, use an inexpensive volt meter to check your power outlets, especially during peak-use times, such as the summer air-conditioning season. Remote Controls: Most DTVs and audio/video receivers come with remote controls that are either preprogrammed with codes for other manufacturers' products, can learn codes from other remotes, or both. For something better, consider internet-enabled models that let you input information about your components on a website, then download the relevant data into the remote via USB. Antennas: Digital television is broadcast on both the UHF and VHF bands. You can find out what frequencies your local stations are using, and determine what kind of antenna you need, at AntennaWeb.org. Putting It All TogetherHooking up a home theater system may seem intimidating. Here is a brief checklist to get you started on connecting an audio/video receiver-based system.Placement: The display should be far enough away to make the dotted pixels invisible. Front speakers on stands should form an arc in front of the screen. If wall-mounted, they should be in a straight line below the screen. Side-surrounds go on the rear of the side walls, back-surrounds on the back wall. The receiver or amplifier needs at least two inches of space above for ventilation. Most components should not be stacked, especially those that run warm. An equipment closet must be ventilated. Video Display: Ideally, a single HDMI connection between video display and receiver is sufficient. Most receivers route all incoming signals through their HDMI outputs, enabling a single-HDMI connection to the display. However, if your receiver does not do this, additional connections may be necessary. Component video is the second best choice because it is HD-capable. Speakers: When using speakers with a subwoofer, use the receiver's setup menu to set speakers "small" and sub "on." When using full-range speakers without a sub, set speakers "large" and sub "off." When using a subwoofer, you will need to set the crossover, which is the frequency at which the subwoofer takes over the task of producing bass from the speakers. The setting may be anywhere from 80 to 120 Hertz—look for it in the speaker manual. There are two ways to set crossover—with the receiver's setup menu, or with the sub's back-panel dial. Whichever crossover you don't use should be deactivated. When using the receiver's crossover, disable the sub's crossover using the bypass switch (or just turn the sub crossover dial as high as possible). When using the sub's crossover, disable the receiver's crossover in the receiver menu. Keep cable runs as short as possible. Subwoofer: Use a single line-level analog interconnect cable from the receiver's "sub" or "LFE" (low-frequency effects) output. Experiment with different sub placements to obtain not just the strongest bass (which will be near corners and walls) but the most even bass. Source Connections: Use HDMI or component video wherever possible—both are HD-capable. S-video and composite video are lower-quality connections—neither is HD-capable. HDMI is both a video and audio connection. However, pre-HDMI components may need digital connections (coaxial or optical) or analog connections (7.1-, 5.1-, or 2-channel). When using a Blu-ray or SACD/DVD-Audio player with an older receiver, use the multi-channel analog connection. For more information on connecting your equipment, visit www.CEAConnectionsGuide.com. Getting Your TV Up to Speed: Run the TV's channel scan to detect your local stations when using antenna or unencrypted broadcast-basic cable. For the ultimate in performance, have your set calibrated by a certified technician. Getting Your Surround System Up to Speed: Either run the receiver's automatic setup routine, if it has one, or run its built-in test tones, monitoring levels with a sound pressure level meter and adjusting them manually. The meter isn't as helpful with subwoofer volume—you may need to knock the sub's level down a few times after the initial setting till it blends with the other speakers. If your receiver has room correction, try switching it on and off to find out which setting you prefer. More Audio Articles to Explore:
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