Home Theater Surround Sound Hierarchy: Why TV Speakers May Not Be Enough
Home theater is the union of two technologies: big-screen HDTV and surround sound. The runaway popularity of flat-panel television sets has brought big screens into more and more homes—and in a form that's more palatable than the hulking boxes of older TV technologies. Unfortunately, these flat-panel HDTV purchases are not always accompanied by a comparable investment in surround sound, so a lot of big-screen-savvy homes are not yet surround-sound savvy.
Aren't built-in TV speakers enough? For watching the news, certainly. And it's unlikely that a surround system will do much to enhance your enjoyment of I Love Lucy. But today's movies—and today's primetime TV programming—are both made in surround sound. That's the way they were meant to be heard and that's the way you should hear them if you want to get the full impact intended by the creative community.
There's no need to panic when you contemplate the transition from the two-channel world to surround sound's 5.1 or 7.1 channels. Don't worry—no hostile army of equipment is going to occupy your home. The system that's right for you can be scaled for your needs and lifestyle. The following primer will discuss four entirely different ways to implement surround sound:
Bar Speakers: The One-Piece Solution
Home-theater-in-a-box systems (HTiB)
Component systems based on a receiver
Component systems based on separate
If you're hanging a flat-panel HDTV on the wall, what could be more natural than hanging a one-piece sound system beneath it and calling it a day? This exciting new product category was designed specifically to complement flat-panel sets.
Types of Bar Speakers: While a bar speaker may look like a bigger version of the horizontal center speaker included in many surround speaker packages, it is something quite different, handling more than one channel. Some bar speakers contain their own amplifiers, and therefore need only to be connected to one or more source components. Others require outboard amplification, such as a receiver.
Bar speakers handle varying numbers of channels. Five-channel models can usually operate on their own, though adding a subwoofer to beef up the bass is often a good idea. Some models handle fewer than five channels and require a pair of surround speakers in the back of the room as well as a subwoofer to sound their best. Others use psychoacoustic spatial processing to mimic surround effects.
Advantages of Bar Speakers: They are the least intrusive surround sound solution. Visually, they harmonize with your flat-panel HDTV, especially if you match the width of the bar to that of the set. And if you think all bar speakers are low-end products, you might be surprised to discover the existence of high-end models that perform extremely well. Some of the most ingenious speaker designers in the business, from some of the most reputable brands, have begun to apply their talents to bar speakers.
Disadvantages of Bar Speakers: Typically the soundstage—the perception of a field of sound in front of the speaker—is limited to the width of the speaker. This usually makes bar speakers unsuitable for large rooms. Some designers work around this using either psychoacoustic processing or drivers at the sides. Furthermore, as one-piece solutions, bar speakers are resistant to piecemeal upgrading.
Home-Theater-In-A-Box (HTiB): The One-Box Solution
If you want to distribute speakers around the room, but don't want all the fuss that goes with equipment matching, a home-theater-in-a-box system could be the solution for you.
Types of HTiB Systems: HTiB embraces a wide variety of system architectures. The number of speakers in the system may vary from two to 5.1 to 7.1—the “.1” is always a subwoofer, which produces low bass. Some of the two-channel versions incorporate some kind of psychoacoustic magic to produce surround-like effects. Most HTiBs come with an amplifier/controller specifically designed to drive the speakers. Some of these amplifier/controllers include a disc drive, either DVD (which is not HD-capable) or Blu-ray (which is HD-capable). Speaker cables and a remote control are usually included, so you needn't buy accessories—just uncrate the product, hook everything up, and you're ready to roll.
Advantages of HTiB Systems: HTiBs are well-suited for small rooms. With an HTiB, you never need to worry if the amplifier is powerful enough to drive the speakers. Everything is designed to work as a system. While some HTiBs have low-end pricetags and sound to match, there are some high-end selections that perform surprisingly well.
Disadvantages of HTiB Systems: As compact systems, HTiBs are generally ill-suited to large rooms. Their amplification and volume capability are generally limited. They usually have fewer connectivity options than a receiver, and sometimes fail to include HD-capable inputs. They are also less upgradable than a component system, due to the special matching of speakers and amps.
Receivers: Moving Up to Components
For the next step up in performance, get a surround receiver, also known as an audio/video receiver, and pair it with the speakers of your choice. The speakers may or may not be sold as a single-purchase package. DVD or Blu-ray disc players and other signal sources will also be separate purchases.
Advantages of Receiver-Based Systems: Receivers offer the possibility of more power. While the lowest-end models may have no more power than an HTiB, mid- and top-line models are definitely more powerful and can fill midsized or larger rooms with sound.
Receivers also have a lot more features than HTiBs. Among the most crucial is automatic setup, which uses a small microphone to help the receiver set speaker distances, channel levels, and other initial settings that may be intimidating to a newbie. Auto setup is usually accompanied by room correction, which adjusts for acoustic conditions and may achieve more accurate sound. An up-to-date receiver will have on-board decoding for the latest surround codecs such as Dolby TrueHD, Dolby Digital Plus, and DTS-HD. A THX-certified receiver will be designed to work best with a THX-certified speaker package. Other features available on some (though not all) models include Sirius/XM satellite radio reception, internet radio, iPod compatibility, Bluetooth compatibility, and the ability to pull music out of a PC via router. Some of these features may require extra-cost accessories such as a satellite antenna or an iPod dock.
Disadvantages of Receiver-Based Systems: While receivers offer a cornucopia of often useful features, there is a tradeoff between functionality and complexity. The more features there are, the more complicated the user interface becomes, and that's true whether you're working with the onscreen graphic user interface, the front-panel controls, or the remote control. Auto setup solves some of the initial headaches but you'll still have to tackle a fairly thick manual to understand how to adjust settings, select appropriate listening modes, and access other features. Owning a receiver therefore requires some commitment. Set aside some time to explore the menus and instructions before you show off your new system to family members or guests.
Separates: For the Ultimate in Performance
A system based on separates is similar to a receiver-based system, except that the receiver's functions are divided between two separate components, a multi-channel power amplifier and a surround preamp-processor (or pre-pro).
Advantages of Separates: Handling amplification in one or more components allows the amp to be more powerful and to drive more demanding speakers. This makes separates more appropriate for the largest rooms, especially for dedicated home theaters. In the most power-hungry applications, the multichannel amp may even give way to a rack of stereo or mono-block amps. Pre-pros, freed from proximity to hot and power-hungry amp parts, have the potential to perform better than the comparable functions in a receiver. Pre-pros are sometimes built in a modular architecture that allows for future feature upgrades.
Disadvantages of Separates: While separates offer the ultimate in audio performance, adding components to the rack will also involve extra cabling. That will include not only an extra power cord, but also eight analog interconnects to connect the pre-pro to the power amp. And if you opt for a more powerful amp, the system will consume more power.