A surround processor, or receiver, may produce 6, 7, or 8 channels of output, depending on the source and type of surround processing. The basic surround format (“5.1” surround) includes three full-range front channels (left, right and center), two full-range surround channels (left surround and right surround), and a low-frequency, or subwoofer channel. Because the subwoofer channel carries only the lowest octaves compared to the five full-range speakers, it is called the “.1” channel. A “6.1-channel setup” adds a separate full-range “center back” speaker to the 5.1 array. A “7.1”-channel system includes two “back” channels in addition to the surround channels.

What do I look for in A Home Theater Receiver?

First, let's answer the question: "What is a home theater receiver and what does it do?" A home theater receiver serves as the central point of a home theater or home audio system and performs the following functions:

Switching for all of your home theater system's audio and video components
Surround sound decoding
Signal processing for simulated soundfields and bass management
Amplifies the audio signals to drive the loudspeakers and controls the playback volume
Serves as an AM/FM radio tuner

The receiver is both the "smarts" and the "power" behind a home theater system. It takes the audio signals from all of your source components (e.g., DVD-Video player, CD player, VCR, tape deck, turntable), performs any needed decoding and post-processing, amplifies the signal to power your home theater's array of loudspeakers, and controls the playback volume. For video signal, the receiver performs the necessary switching and outputs it to your TV. With all this functionality, a receiver is one of the more complex and expensive components in a home theater or home audio system.

The terms "home theater receiver", "audio/video receiver", "A/V receiver", "surround receiver", "Dolby Digital/DTS receiver", and "receiver" are used interchangeably on this web site, since we're talking about a receiver that has at least five channels of processing and amplification for home theater and multi-channel music sources such as DVD-Audio and Super Audio CD. If you're not familiar with all the terms we just threw out, don't worry. We'll discuss each of these functions in turn. Then we'll tell you what else you should look for, and how to compare and audition A/V receivers when you shop.

We recommend that you choose a receiver or processor with at least two digital inputs: one for your DVD player and one for HDTV. However, many other components incorporate Dolby Digital technology, such as personal video recorders (PVR) and the Xbox, so you'll need additional digital inputs to connect these.

Dolby Digital is the audio standard for HDTV and DVD. So you'll need at least one source component with a Dolby Digital output. (The output may also be labeled AC-3.) This component could be a DVD player, a digital cable or digital satellite set-top box, and/or a digital television (DTV) receiver.

Layout: - The key to picking a surround sound receiver is to find one that matches your speaker layout requirements. Most Receivers will work for Dolby Digital 5.1. Then depending on the model, they should also work for 6.1 or 7.1 surround. See the diagrams below to help you pick the right receiver type.

Each speaker of your home theater needs its own channel of amplification, so a 5.1 system needs six channels and a 7.1 system needs eight. These amplifiers are typically built into audio/video receivers, but there are also many stand-alone multichannel power amplifiers for use with preamp/processor components. (Subwoofers, the ".1" channel, frequently incorporate their own built-in amplification and need only a line-level connection from the subwoofer output to the receiver.)