Over the years, the television has evolved from a chunky living room centerpiece to a slim Internet-connected display that supports enough components to warrant an entire room of its own. The goal? Bringing the movie theater experience right into the home, which means bigger displays and better sound.
Setting up a home theater system doesn't have to cost a bundle and you don't have to buy it all at once. Here's how to bring multiplex-quality sound to your TV without a Hollywood blockbuster's budget.
The geometry of audio
More speakers do not necessarily mean bigger, richer sound, as a look at the geometry of speaker placement reveals.
One speaker, of course, can fill a room with sound. But no matter where you are sitting, elements of audio such as dialogue, music and effects seem as if they are coming from the same place (because, well, they are).
Add an additional speaker and now you have stereophonic audio, with sound coming from two directions that mimic the way your ears perceive sound in the natural world. You can sit anywhere along an imaginary line created midway between the two speakers to hear a stereo soundtrack as it was intended to be heard.
Today, motion picture audio is engineered in multiple channels designed to be played through a multiple-speaker surround sound system. As with picture quality on HDTV, you’ll need the proper equipment in order to hear a film’s sound the way moviemakers intended.
Once you add one or more speakers to an original pair, however, the best place to experience emitted sound shrinks to a point. Now there is only one spot where a listener can sit and hear the audio perfectly. That means if you regularly host a crowd for movie night, guests in the middle of the room will have a better experience than those seated elsewhere. For example, guests to the sides might hear too much of the car crash on the left and not enough of the jet on the right.
Modern surround sound
Surround sound moves sound from two channels to as many as 11, and allows listeners to hear multiple sounds from as many directions as there are speakers in a system. Audio channels are carefully engineered to produce sounds that mimic real environments and even give the impression that sound is moving from one part of the room to another.
Until this year, surround sound came in three main flavors: 2.1, 5.1 and 7.1. At the Consumer Electronics Show in January, DTS introduced its Neo:X 11.1 systems, which it paired with 3-D HDTVs. The first number refers to the number of speakers that project the mid-range and high frequency sounds. The .1 refers to a single subwoofer, a piece of audio equipment that produces low sounds.
A home theater's subwoofer can be placed anywhere in the room. Since the deep-bass frequencies boomed out by the subwoofers are non-directional, it is difficult for our ears to pinpoint where the sound is coming from. That's the reason why human ears hear distant thunder as a low rumbling all around when the sound is actually coming from a specific place.
The addition of mid- and high-frequency speakers in home theater systems follows a progression. The first four speakers are placed near the corners of a room. The front speakers provide the main soundtrack while the back speakers usually play "moving" sound effects such as rolling thunder and racing cars. The fifth speaker in a 5.1 setup, known as the center, is placed in the front of the room and is used primarily for dialogue.
Move up to 7.1 and the two back surround speakers will shift slightly forward to make room for two more back surround speakers, creating even more nuanced effects. Ideally, all speakers should be angled toward the room's primary viewing spot.
Home-theater-in-a-box systems are available from most manufacturers starting at around $300. They usually represent the lower end of the market, but offer simplicity with a matched 5.1 set.
A piece of audio tech known as a sound bar is a great solution if you're looking for ease-of-installation. A sound bar is placed above or below the TV and mimics the effects of surround sound by producing extremely small sound delays. Look for a sound bar that has a separate subwoofer so you don't lose out on the bass.
If you want real surround sound with room to upgrade and expand, start with a good receiver. The audio signals from your home theater components — including HDTV, cable box, Blu-ray player and other display devices — will run through the receiver to the proper speakers via HDMI cables. If you anticipate a future seven-speaker system, you should buy a 7.1 receiver now, which will run between $400 and $500. A 5.1 system can cut the cost in half.
A good speaker produces sounds from 60Hz to 25kHz. However, if you're over 30, you probably can't hear frequencies over 14kHz, according to Don Rath Jr. a chamber music composer and teacher, on his music education site. Save your money: a pair of Polk speakers rated up to 20kHz is half the price of a pair of 25kHz speakers at Best Buy.
For under $500, you can get a solid start on a home theater system that may prove good enough, but if you decide to upgrade, you won't have wasted your money.
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