If you are in the market for a home theater sound system, you may be suffering from audio indecision. Selecting from the enormous variety of available sound technology can be overwhelming. This article will take the mystery out of shopping for a home theater sound system.
Before you can choose the right setup, you need to know what your options are. This primer on home theater sound equipment should help.
Front Speakers—Your classic left and right speakers. These go on either side of your TV or projector screen. They play special effects audio tracks.
Center Speaker—The workhorse speaker for the home theater. As part of a 5.1 or larger sound system, the center speaker plays dialogue.
Rear Speakers—Typically lighter and smaller than front speakers, these play the ambient sounds in film soundtracks. Place them behind or to the side of your theater seating. You will hear chirping birds, wind, traffic and other background noises from these speakers. The best rear speakers are dipole, bipole or dipole/bipole; meaning that they emit sound in more than one direction. This creates a diffuse cloud of sound. When the characters in your game or movie are in a jungle, you will hear jungle animals all around you, not coming from a distinct point behind your right shoulder, for example.
2.1 Speaker System—The most basic and affordable speaker setup. Two speakers and a subwoofer. Some come with virtual surround technology that tricks your ear into thinking that sound is coming from different places. Virtual surround throws sound like a ventriloquist.
5.1 Speaker System—Two front speakers, one central speaker and two rear speakers to create surround sound. 5.1 is the most common way to achieve surround sound at home.
6.1 Speaker System—Exactly like a 5.1 channel system, but with an additional rear speaker.
7.1 Speaker System—This system adds yet another rear speaker to bring you up to four rear speakers, two front speakers, one central speaker and a subwoofer. Most action films have 7.1 channel sound tracks.
Subwoofer—Makes the bass go boom. Subwoofer is a magical word for both audiophiles and film buffs. A good subwoofer adds rich tones to music. If you want to feel onscreen explosions in your bones, you need powerful bass.
AV Receiver—The AV receiver is the control center of the home theater. All your audio and video equipment connects to the receiver. It amplifies the sound signals and decodes them for surround sound systems. If you have a receiver you don’t need another amplifier, but as I’ll explain later, you may want one. All receivers get radio signals. If you look hard, you can find an AV receiver with only these functions. However, most receivers offer an array of features from 3D capability to media streaming.
Sound Bar—Literally a bar of speakers. A sound bar houses left, right and center speakers in one space-saving piece of equipment.
What Do I Need?
Now that you understand your options, here are some guidelines for picking the right system for your home theater.
Space and Power
The first thing to consider is the size of your home theater. If you have a large room, you need more power. To create a real cinema quality experience in a large home theater, you will need powerful speakers that can fill your room with sound. An AV receiver alone typically does not deliver enough power to drive very large speakers. You will need a separate amplifier. You can route your amplifier through your receiver or use a preamp that has all the ports as an AV receiver, but no amplifier. Some audiophiles prefer separate components over receivers, because it keeps the mighty amplifier away from the delicate internal mechanisms in the receiver.
Matching Your Speaker to Your Amplifiers
Instead of launching into a lecture on Ohm’s Law and electrical impedance, I will just tell you that to get the best sound out of your speakers you must match their impedance to the impedance of your amplifier. Impedance is measured in ohms. Speakers with lower impedance, say 4 ohms, need more power from the amplifier. If you have a 4 ohm speaker paired with an 8 ohm amplifier, your impressive speakers won’t get the power they need and they’ll end up sounding tinny and sad. Match your ohms for happy speakers and amplifiers.
Bring on the Bass
Have you ever wondered why deep bass sounds need their own, separate house in a speaker system? It’s a pretty simple principle. Low frequency sounds require larger instruments. An upright bass is bigger than a violin. Men have longer, thicker vocal chords than women. A grasshopper is smaller than Barry White. In a sound system, relatively small speakers can produce a wide range of high frequency sounds. Until recently, frequencies below 100Hz needed a big booming subwoofer. Now, compact subwoofers can produce deep, powerful bass. However, you get more boom for your buck with big subwoofers.
Here are some guidelines for choosing a subwoofer:
Frequency—When shopping for a subwoofer look for the frequency range, measured in hertz (Hz). Anything below 100Hz has plenty of bass for small and medium sized home theaters. If you have a huge home theater, go lower. If you want bass that that will rattle your windows, shake your soul, fill your room with earth-shattering sound; look for a sub that goes all the way down to 30Hz.
Power—Unpowered subwoofers require an amplifier. Remember to match subwoofer ohms to amplifier ohms. Powered subwoofers have their own internal power source, and therefore no need to match ohms.
Size—If you are going to place your subwoofer in a wall or cabinet, check the dimensions before you purchase.
Beauty and the Sound Bar
Many home owners shudder at the thought of towering speakers, boxy subwoofers and rampant cables crisscrossing their living rooms. Others see sound and video equipment as objects of beauty. Personally, I feel great affection for my speakers and subwoofer and I like looking at them. However, home theater owners in the first camp are buying up sound bars. With multiple sound channels in one continuous, elegant strip, sound bars give an impression of surround sound without actually having to place speakers around your room. Good ones use advanced audio technology to throw sound, improving the sensation of surround sound.
Bear in mind that most sound bars require a separate subwoofer; which usually depart from the sleek, linear design. Some high end bars extend to very low frequencies, enabling them to produce low bass noises without a subwoofer. These completely self-contained systems offer a huge improvement over your TV’s tiny, tinny speakers and are a popular option for home theater owners unwilling to mount five speakers.
Sound bars are far from the only option for maintaining a sound system with a low profile. In-wall and in-ceiling speaker systems provide true surround sound without taking up floor space. Improvements in home AV technology have increased the popularity of home theaters. In response, manufacturers are churning out furniture specialized to present the pretty parts of your audio-video system while keeping wires hidden and neat. These days even the most particular home decorators can choose a sound system based on audio quality alone and make it fit into their homes beautifully.
Sound on a Budget
There are a few ways to reduce your home theater sound system spending. Sound bars are something to consider if you don’t have the budget for a real surround sound. If you can swing it, buying a complete set of matched speakers is generally cheaper than purchasing individual components.
For what it’s worth, here’s what I would do if I were starting a home theater with limited funds. First, I would look for an inexpensive receiver capable of decoding 7.1 sound channels. Then I would invest my money in a good 2.1 system. Receiver technology is developing quickly. If you’re on a budget, consider skimping a bit here and investing in a great receiver later when the technology is further along. Speaker technology changes slowly. A good set won’t get out of date. 2.1 is all you need for music and simply upgrading your sound quality will improve your movie viewing experience. I still remember the first time I heard the original “Dawn of the Dead” soundtrack coming through my big sub. I would use my sound budget on a great 2.1 set and add a center speaker and surrounds later. Your receiver settings will adjust your sound balance for you as you add speakers.
5.1 Channel Sound or More?
Most customers looking for a home theater sound system settle on a 5.1 surround sound system. The difference between 5.1 and 6.1 is one rear speaker for an extra source of ambient sound. As you continue on to 7.1, 8.1, 9.1 you are simply adding more rear speakers. Most home theater owners are perfectly happy with two rear speakers.
There are two reasons to consider adding more surrounds to your sound system. Firstly, size matters. If you have a large home theater, more rear speakers will help fill the room and round out your sound. The bigger your room, the more rear speakers you will need to achieve an immersive sonic experience. Secondly, blockbuster action films typically have 7.1 channel soundtracks. If you are an action flick fanatic who wants “Man of Steel” to sound the same in your home theater as it did on the silver screen, you gotta have a 7.1 system.
The Right Receiver
AV receivers can come with an array of new-fangled features. Fortunately, when picking the best receiver for your sound system or the best sound system for your receiver there are only a few important features.
As the name implies, AV receivers take in signals from your audio and video equipment. Before purchasing a sound system, make sure that your speakers can plug into your receiver. Match the speaker output to the receiver ports. The graphic below shows different types of connectors you are likely to find on home theater equipment.