How to Buy an Integrated Home Theater Audio System
Introduction
Almost everyone wants a home theater with great surround sound and thundering bass. On the other hand, most people don't want the hassle that often comes with choosing and installing the equipment. This has led to the development of a wide variety of integrated home theater audio systems--a category often referred to as "home theater in a box," or HTiB. One, or maybe two, cartons contain everything you need to add surround-sound excitement to your video setup. Here's what you need to know before you buy.
HTiB systems range from the very basic, designed to plug into your TV set and be ready to go, to the very sophisticated, with features like built-in DVD players and performance rivaling that of elaborate component rigs. more
Of the many specifications used to describe audio systems, you may be surprised at the few characteristics that are really important. We help you demystify those cryptic names and numbers. more
Before you head to the showroom, check out these simple keys to choosing the home theater audio system that's right for you. more
The Big Picture
An integrated home theater audio system, or home theater in a box (often abbreviated as HTiB), includes all the equipment you need to add surround sound to your TV or video system. Some systems are more elaborate than others, and some include significant additional features, such as built-in DVD players. The basic elements, however, are these:
- Speakers for at least five channels of audio--left and right front speakers, two surround and one center
- An amplifier to drive the speakers
- A control center that connects to your video sources--DVD player, TV, digital video recorder, and the like--and decodes the multichannel audio signals from DVDs, TV programs, and so forth for delivery to your speakers. For many people, a standard home theater receiver can do double duty as a control center and an amplifier.
- Speakers first. Speakers affect sound quality more than any other part of a system. So try to listen to a system before you buy. All else being equal, a system from a company that specializes in loudspeakers is likely to have better speakers than one from a company known primarily for its electronics.
- Think digital. For the best possible surround sound from DVDs, make sure the system provides Dolby Digital decoding.
- Check your inputs and outputs. Make sure you have all the inputs and outputs necessary to accommodate whatever equipment you expect to route through the controller. For example, if you want to connect audio and video from a progressive-scan DVD player, look for component-video inputs. Another potential "gotcha" involves digital audio connections, which come in two flavors--optical and coaxial. Be sure you can match the types of digital inputs and outputs on the devices you want to connect.
Prices range from a few hundred dollars for extremely low-end systems to several thousand for the most ambitious. Systems with good overall performance, sound quality, and bass typically start at around $500.
Speakers
Systems typically include five to seven relatively small satellite speakers plus a considerably larger bass module, or subwoofer, which reproduces most of the low frequencies.
The satellites break down into three functional categories: center, front left and right, and surround. The center speaker goes directly above or below the TV screen (usually right on top of the set). Front left and right satellites are placed at the sides of the screen, at equal distances from it. Although the two main surround speakers are often called "rear speakers," they really should be positioned just slightly behind and along the sides of the seating area whenever practical. (An extremely bare-bones system might include just a single surround speaker for placement at the back of the room, but this is rare nowadays.) Many systems use identical satellites for all locations, while others may have somewhat different speakers for the center or the surrounds. The center may be designed specifically for horizontal placement, for example. What's important is that their tonal character be the same.
The subwoofer can usually be placed just about anywhere that's convenient, though its sound will vary somewhat depending on its placement and the acoustical characteristics of the room. Design details, such as whether the subwoofer cabinet is sealed or ported (which means there is a hole or vent in the box), are seldom a significant shopping consideration. Be aware, however, that it is harder to get strong deep bass from a small box than from a large one. That doesn't mean you have to buy a huge subwoofer to get good sound, but don't expect miracles from a tiny one.
That's it for a standard 5.1-channel setup (five plus the bass-only ".1" channel handled by the subwoofer). Some systems provide one or two additional back-surround speakers for 6.1- or 7.1-channel operation. These additional back-surround speakers should be positioned behind the seating area.
One other category, which has grown over the last few years, comprises systems that use special virtual-surround circuitry or speaker configurations to approximate the sound of a multispeaker installation from a single pair, or even a single box, at the front of the room. Obviously, this is a lot more convenient than running wire all over the room to feed surround speakers at the sides or back. And the best of these systems do a surprisingly good job. However, none of them perform as well as a good multispeaker setup. Always listen to such a system before you buy, paying attention to the quality of the sound off to the side as well as directly in front of the speakers.
Amplifiers
An amplifier strengthens audio signals enough to drive the loudspeakers. A system's amplifiers may be built into the individual speakers, into the subwoofer (in which case all the satellites connect to the subwoofer), or into the control center that contains the surround decoder. When a manufacturer creates a system by packaging a regular audio/video receiver with a set of speakers, the amplifiers for the satellites will normally be in the receiver and the amplifier for the subwoofer in the subwoofer itself. Any of these configurations can work very well, and there is no reason to prefer one over the other in terms of performance.
Control Center
The system hub is a control center that provides surround-sound decoding, volume control, and other basic functions. (Often it will be a standard audio/video receiver.) An extremely simple unit might provide just one set of audio inputs, for connection to the audio outputs on a TV set. Most, however, provide multiple inputs and the ability to switch between them using a remote control.
In a system with Dolby Digital decoding capability, at least one input will be digital. Dolby Digital is the standard audio format for DVD and HDTV, so this capability is highly desirable. At minimum, you should expect Dolby Pro Logic or Pro Logic II decoding, which will work with just about any surround-encoded soundtrack you encounter. (Since devices such as DVD players, which are designed for Dolby Digital, provide Pro Logic-compatible analog outputs as well, you will not be left out in the cold, although the quality of the surround will be somewhat lower.)
Many control centers provide video as well as audio switching. That allows you, for example, to connect the audio and video outputs from a DVD player and a VCR to the control center, and connect its audio and video outputs to one set of inputs on the TV, with all switching done through the control center. Some also have built-in DVD players for watching DVDs and listening to CDs.
Choosing a System
Pay attention to the speakers and a handful of details, and it's hard to go wrong.
The Specs Explained
Among the many characteristics that define an audio system, only a relatively small number are really important to making a good buying decision. Here are the key specifications for a home theater audio system. We've divided them into three groups: important, somewhat important, and minor.
Important: Surround Decoding
The surround-sound formats supported by the system will affect the realism and intensity of the experience.
Important: Frequency Response
Frequency response measures both the range of frequencies that can be reproduced, from lows to highs, and the evenness of their reproduction. For example, you might see something like this: 40 Hz to 20 kHz, +/-3 dB. That means low frequencies from 40 Hz (cycles per second) to high frequencies up to 20,000 Hz (the approximate upper limit of human hearing) are reproduced with no more than 3 decibels of deviation from perfect accuracy ("flat" response).
The part of all this that is worth paying attention to is the low-frequency limit. For most music and many movies outside the action and sci-fi genres, a lower bass limit of 50 Hz will do. Pushing the bass down to 40 Hz will ensure that you never feel seriously deprived. And if you get it down to 30 Hz or below, you can feel some pretty bone-rattling effects.
Important: Audio Inputs
The number and type of audio inputs available in the control center or audio/video receiver determines how many sources you can connect to it and what you can do with their outputs.
Somewhat Important: Speaker Configuration
Surround encoding and playback is defined according to a number system.
For example, Dolby Surround is a 4.0 system, with front left and right, center, and mono surround channels. Dolby Digital is a 5.1 system, with front left and right, center, left and right surround, and low-frequency effects channels. (The LFE is the ".1 " channel.)
Dolby Digital EX is a 6.1 system. The speaker systems used to reproduce these formats are usually 5.1, 6.1, or 7.1, with the latter two adding one or two back-surround speakers, respectively, in addition to the standard left and right surrounds. In this context, the ".1 " refers to a subwoofer (which will usually reproduce deep bass from the main channels in addition to the LFE). In some cases one surround channel may be routed through two surround speakers, as in a Dolby Pro Logic decoded Dolby Surround soundtrack in a 5.1 system or Dolby Digital EX in a 7.1 system.
Somewhat Important: Video Inputs
These are only somewhat important because you usually don't have to route video signals through the audio control center. But video inputs can be a convenience.
Minor: Amplifier Power
Surprised? A speaker's ability to reproduce sound loudly depends on both amplifier power and the sensitivity of the speakers, which is seldom specified for this type of system. Highly sensitive speakers don't need nearly as much power as less-sensitive ones to sound just as loud. For example, a speaker with 91-dB sensitivity will sound just as loud with a 50-watt amplifier as a speaker with 88-dB sensitivity will with a 100-watt amp. And because amplifier power is cheap these days, it's rare for any systems, other than very low-end ones, to be underpowered. The shortcomings tend to be elsewhere.
Home Theater Audio Shopping Tips
Ready to go shopping? Here are our tips for bringing home your own personal best buy.
PCWorld Staff
