Home Theater Surround Sound

Good stereo can create a holographic space that puts the soundstage in front of you.

But surround sound can create a whole new environment all around you.

First, determine what kind of system you’re creating.

How Many Speaker Channels?

Right now it seems to be a race: 5.1, 6.1, 7.1, 9.1, even 11.1 speaker channels. Here’s what you’ll need for different media:

5.1 channels: Most DVDs and Blu-ray Discs, some Super Audio CD (SACD) discs, some streaming sources

6.1 channels: A few DVDs with Dolby Digital Surround EX™ or similar encoding

7.1 channels: Some Blu-ray Discs (with more coming soon)

A good 5.1-channel system can give you the full surround sound experience.

Going to 7.1 channels improves the directionality of sound effects and adds to a 3D audio ambience.

A 9.1-channel format, like Dolby Pro Logic® IIz, adds a pair of front height channels. These added channels are derived from audio cues present in the signal.

The Best System for You

More channels mean more speakers and more amplifier power, which add up to more money. You’ll most likely be very happy with a 5.1-channel system.

If you’re a dedicated audiophile or cinema enthusiast, and have both the room and budget, then by all means investigate the more complex setups.

Take a look at some examples of equipment best suited for 5.1-channel sound and 7.1-channel sound.

Check out AVRs with Dolby.

Choosing Your Speakers

Nothing substitutes for listening to the speakers you’re thinking about before you buy. But where do you start?

With thousands of speakers out there, stores carry only a relative few. And side-by-side comparisons are often not that useful. For one thing, the showroom will sound much different than your listening area at home .

Make your room size your starting point.

Bigger = Better?

Generally, smaller speakers won’t play loudly enough in a big room, and large floor-standing models are wasted in a small room.

There is no correlation between size and quality, and little between size and price. Many small speakers are of extremely high quality (and are usually priced accordingly). Having a small room doesn’t mean you have to sacrifice quality.

Judge for Yourself

Here are a few tips:

Determine your budget before you shop.

Read some reviews to narrow your choices.

Take your own demo material to the store. Choose discs or movies you know well.

If a store doesn’t let you use your own discs, shop somewhere else.

None of us hears in exactly the same way. Trust your own ears.

Speaker Setup

Take a look at the Dolby Home Theater Speaker Guide for complete information on speaker placement for any configuration. You’ll learn the advantages of each configuration and the role of each speaker. 

A/V Receivers: The Heart of the Component System

If you choose a component system, the  A/V receiver (also known as the AVR) is your control center and power source. It combines:

A preamplifier with audio and video controls, processors, inputs, and outputs

A power amplifier to drive the speakers

A radio tuner for FM and sometimes AM and satellite bands

Everything in your home theater system connects to the A/V receiver. Be sure you get one with several HDMI inputs and enough other inputs for all your sources. See the Connections section. [link to subsection 4.2: Home Theater Connections]

Find A/V receivers with Dolby technologies.

If you play LPs or plan to, make sure the receiver has a phono input. If not, you’ll need a separate phono preamplifier. (These start at about $150.)

How Much Power?

The simple answer is “as much as you can afford.” Look for around 50 to 80 watts per channel minimum.

You can’t have too much power, but you can have too little. Surprisingly, small speakers sometimes require more power than larger ones. Check the power ratings for your speakers and don’t go under that. It’s best to get more power than you think you’ll need.

See Power Ratings in the Tips section for more details.

Room Calibration

Nearly all A/V receivers now include room calibration to help you fine-tune your speaker placement. It uses a microphone (generally included) and self-generated test tones. The more expensive the receiver is, the more sophisticated the circuitry.

Other Features

Full-featured A/V receivers offer many additional features that can improve your experience. Here are a few to look for:

Advanced surround sound processing, such as Dolby TrueHD

Video upscaling to improve the quality of lower-resolution videos

USB connectors for the PC

Docks for popular MP3 players

Wi-Fi™ capability

Ethernet connectors for direct Internet

Built-in volume leveling, such as Dolby Volume

Separate Components
HTIBs
Sound Bars
Speakers from One Manufacturer
Multichannel Playback
MP3s
Power Ratings 

Although owner’s manuals for A/V receivers can seem more complicated than the products themselves, reading some manuals before you buy can help you make a better choice and save you a lot of time later.

What About Separate Components?

Separates—specifically power amplifiers and preamplifiers (or control centers)—are an alternative to A/V receivers. Advantages include:

Flexibility—more easily expandable, especially for adding channels

Power capability, a consideration in large rooms

Potential for better overall performance

The disadvantages of using separate components include:

Space requirements

Complexity

Expense

What About Home-Theater-in-a-Box (HTIB) Systems?

These prematched, close to turnkey systems offer a number of advantages:

Simpler choices

Slightly easier setup

Often a great option for small rooms

Disadvantages include:

Quality and size often directly related to the price

Sometimes difficult to upgrade

One-size-fits-all system not ideal for all rooms

What About Sound Bars?

Sound bars are a very room-friendly alternative to separate loudspeakers. Many offer “virtual surround,” simulating a five-speaker setup from just two channels.

As with any system, there are trade-offs:

Efficient use of space, easy to hook up

Huge improvement on built-in TV speakers

Surround effects limited to very small “sweet spot”

See a sound bar with Dolby technologies.

Speakers from One Manufacturer

Your speakers need similar “sound signatures” to create the most convincing surround effects. Choosing all your speakers from the same manufacturer will help ensure that consistency.

Most of the major manufacturers now offer prematched home theater sets, saving you the trouble.

Multichannel Playback from Your Stereo Recordings

Most receivers include Dolby Pro Logic II (or IIx or IIz) that can generate surround sound from any stereo source:

Vinyl LPs

CDs

Videocassettes

The effect will vary, but live recordings in particular will deliver dramatic spaciousness.

If your receiver offers Music and Movie modes, use those modes for listening and viewing.

MP3: Don't Expect Too Much

Strangely enough, MP3 music recordings that sound great through earbuds on your commute probably won’t sound as good on your home theater, especially at higher volumes. MP3 files are highly compressed, and you’ll hear the difference very quickly.

Power Ratings

Receivers and amplifiers are rated in watts per channel. A typical spec for an A/V receiver is 100 W × 5, meaning that each of the five channels can deliver 100 watts.

Ideally, all channels would be capable of delivering those 100 watts simultaneously, but this is usually not the case except for top-of-the-line models or separate power amplifiers.

In everyday use, it doesn’t matter that much—it’s very rare for any movie soundtrack or music to reach peak levels in all five channels together.

Although most speakers will play pretty loudly with only a few watts of input, you need the extra power to handle peaks, such as the sound of a gunshot.

Every 3 decibel (dB) increase in sound level (the minimum increase you can hear) requires doubling the power. A change in sound from 85 dB to 105 dB could easily mean going from 1 to 100 watts, even for an instant.