Whether you're building a system capable of delivering full-on home theater thrills, or one that's intended exclusively for listening to music, you'll find that your receiver is a crucial component.

The receiver handles a wide variety of tasks. It powers your speakers, tunes in FM and AM radio stations, provides convenient switching between audio/video components, and lets you tailor the sound of your system to suit your room and preferences. Home theater receivers also provide the decoding that lets you enjoy movies, TV shows, music, and even video games in enveloping surround sound.

Many of today's receivers make it easy to add optional entertainment sources to your system, such as satellite radio, portable MP3 players, and music files stored on your computer. Some models even let you use your PC for system setup and control — a very handy feature for custom installations. Use of some iPod® models for remote control and even direct music streaming is another emerging capability.

Simply put, the receiver supplies both the brains and the muscle for your system. That's why it's especially important to select a model that meets all of your needs.

A home theater receiver is command central for your A/V system — it powers your speakers, provides surround decoding, and enables easy switching for your DVD player, CD changer, cable/satellite box, and more.

Should I get a home theater or stereo receiver?

When shopping for a receiver, the first decision you'll need to make is whether to buy a home theater or stereo model. If, like most people, you want to enjoy surround sound in your main TV-viewing room, you'll need a home theater receiver. But for other rooms where you don't need surround sound (or don't have space for all those speakers), a stereo receiver can be a great choice, especially for listening to music.

But what if your primary interest is music, not movies, even in the room where you're putting together your main system? There are still some compelling reasons to consider a home theater receiver. These models offer digital processing modes that let you transform stereo music into convincing multichannel surround sound. Plus, home theater models offer the convenience of digital inputs and outputs(see for details).

Most home theater receivers also give you automatic speaker calibration. This helpful feature allows the receiver to analyze and automatically adjust the sound of your loudspeakers, for a more accurate response in your listening room. The audible benefits of this technology can apply to both two-channel stereo and surround sound. Watch our short video on auto calibration to learn more about this useful technology.

A quick look at surround sound

If you're new to home theater, the wide array of surround sound options can seem a bit overwhelming. Don't worry, though — all of today's home theater receivers will let you enjoy your music, movies, TV programs and video games in enveloping surround sound. Along with decoding Dolby® Digital and DTS® soundtracks found on DVDs, HDTV broadcasts, and other programming, all current home theater receivers offer — at minimum — the five channels of amplification necessary to reproduce 5.1 surround sound. (The ".1" in 5.1 refers to the dedicated subwoofer channel; subwoofers are almost always self-powered and therefore do not require amplification by your receiver.)

Most new home theater receivers are capable of delivering additional surround choices with up to seven channels of power and the processing needed for even more three-dimensional sound. A growing number of models also include built-in decoding for advanced surround formats including Dolby® TrueHD and DTS-HD® Master Audio — two new high-resolution surround options available on select Blu-ray high-def video discs and players. (See our article about surround sound formats to learn more.)

Receiver power: Not all watts are created equal

Whether you go for a home theater or a stereo receiver, a couple of basic rules apply. Make sure that the receiver has enough power for the speakers you'll be using it with and the room you'll be using it in. The sensitivity of your speakers will help you determine whether a receiver is a good match — lower sensitivity ratings indicate power-hungry speakers that will require more "juice" from your receiver to produce the same volume as speakers with higher sensitivity ratings. Also, in general, the larger your listening room, the more power your receiver will need to deliver satisfying sound.

Evaluating power ratings
The benefits of increased amplification hardly end with sheer volume, though. All other things being equal, a receiver with more wattage will deliver more dynamic, detailed sound than a receiver with less wattage, even at low to medium volumes. But when you're comparing the power ratings of one receiver to another, bear in mind that not all watts are created equal. Some receivers employ more stringent guidelines in their power ratings than others. A full-bandwidth power rating is performed over the entire range of frequencies audible to human ears — 20 to 20,000 Hz — and is a more reliable indicator of quality amplification than ratings performed over a smaller frequency range (or those rated at just a single frequency, such as 1 kHz).

How "clean" is the power?
Another piece of the power rating puzzle worthy of note is total harmonic distortion (THD), which indicates how accurately a receiver can amplify music and movie sound. THD measurements for receivers almost always fall below 1%, so on first glance these ratings may seem to be almost indistinguishable from one another. But even small differences can be meaningful. The receivers with the cleanest amplification will typically have THD levels below 0.1%.

Want more sonic punch? Look for high-current power
The dynamic peaks that help make movie soundtracks and music so exciting can impose intense short-term demands on a receiver. High-volume special effects such as explosions or loud orchestral passages can quickly deplete a receiver's power reserves, resulting in sound that's flat and uninvolving. Models with high-current power are particularly well-equipped to handle these challenges, reproducing dramatic surges of sound with more punch and greater fluidity than other receivers with similar wattage ratings.

Connectivity: The ins and outs of building a great system

Another important consideration when selecting a receiver is the variety and number of inputs and outputs it offers. Make sure you get a model with enough inputs to handle all your audio and video components, preferably with some room to expand your system down the road. Many home theater receivers offer only two or three audio-only inputs, but considerably more audio/video inputs. If this division seems a little lopsided for the components in your system, bear in mind that any audio/video input can easily be used for an audio-only source.

Digital audio outputs — great for recording
All home theater receivers feature digital audio inputs, but a good number of them do not offer any digital audio outputs. If you've got a digital recording device — especially a component-style CD burner — you'll likely want to get a receiver with a digital output that is compatible with the digital input on your recorder. This allows a direct digital connection between your source component and your recorder for maximum fidelity recordings. Otherwise, the audio signal will go through several stages of digital-to-analog and analog-to-digital conversion that will reduce the sound quality.

Keeping a turntable in your system?
If you plan to have a turntable in your system, you'll probably want to get a receiver with a phono input. Many home theater receivers, and even some stereo receivers, do not offer a phono input. You can still hook up a turntable to a receiver without a phono input, but you'll need to add a separate phono preamp, or a turntable with a built-in preamp.

Advanced receivers like this one offer an amazing array of inputs and outputs. This lets you hook up all the components you've got now, and also gives you room for system expansion later.

Switching between video components
Video components come in all shapes and sizes, and offer a variety of connection options. Some video connections provide greater accuracy and more detail than others. When you're hooking up a video component, try to use the best connection possible to get the best picture quality for your system. For a look at the most common types of video connections, check out our article on audio/video interconnects.

Receivers with HDMI switching let you connect two or more components via HDMI — a great option if your TV doesn't have enough HDMI inputs. For even more convenience, check out receivers with HDMI conversion or upconversion, discussed below.

Why would you connect your video sources to a home theater receiver? Well, these days, most home systems include plenty of video components, including cable or satellite TV tuners, DVD players and recorders, high-def video disc players, game consoles and more. Some folks find that their TV just doesn't have enough video inputs, or enough of a certain type of input, to accommodate all their gear. That's when using a receiver's video switching capability can be really handy.

Once your sources are connected to a home theater receiver, you can choose the one you want to watch, and send the selected video signal out to your TV for viewing. This is especially important when it comes to HDMI-equipped components. That's because many HDMI components will only pass their top resolution video signal via HDMI. HDMI is also your only connection choice if you want to watch 3D TV (more about that later). So it would be to your advantage to just make an HDMI connection through your receiver and use its HDMI switching capabilities to select your sources.

However, there are some issues to keep in mind when choosing the video connections you'll use. Unless your receiver offers video conversion (see below), you'll have to make a matching connection to your TV for every type of video connection you make to your receiver.

For example, if your DVD player is connected to your receiver via composite video, your receiver will have to send the DVD signal to your TV via another composite cable. Similarly, signals sent to your receiver's component video inputs will only be sent out through its component video outputs.

So, if you've got several different video sources and you want to get the best possible video quality from each, you'll very likely have to make two or more video connections between your receiver and your TV. If you'd like to streamline your setup while maintaining top picture quality, and save a little extra money on cables, read on.

Video conversion — better quality in a single connection
Receivers with video conversion offer a lot more switching flexibility and convenience. What is video conversion exactly? It's a receiver's ability to accept a variety of incoming video connections from the components in your system and pass them all to your TV through a different type of video connection. The most common types of video conversion are:

• Composite-to-S-video conversion. This lets you send a variety of A/V sources to your TV through a single S-video connection. It works with any video signal entering your receiver via a composite video or S-video input.
• Component video conversion. This type of video conversion is more flexible still, letting you send signals from composite, S-video, and component video inputs to your TV via a single component video connection.
• HDMI video conversion. This versatile form of video conversion allows you to send the video signals from all your composite, S-video, component video, and HDMI inputs to your TV using a single HDMI cable.

Video conversion does not improve the video quality of any of your sources, but it does maintain the best possible quality for each. A lot of folks like video conversion because it means you don't ever have to change your TV's input settings when you switch among video sources on your receiver. That's particularly handy if you or someone in your household isn't comfortable with making changes in your system's settings.

Video upconversion — help your non-HD sources look better
Along with basic video conversion, some receivers offer video upconversion, or "scaling." Video upconversion means your receiver can process and upgrade any non-HD video source to a higher-resolution video signal that more closely matches the capabilities of your HDTV. This gives your DVDs and older video sources a crisper, more detailed look. However, there are limits — don't expect your VHS tapes to look high-def. Watch our short video on HDMI conversion and upconversion to see how you can make the most of this advanced technology.

If you plan on switching your 3D video sources through your receiver, you'll need one capable of passing 3D video signals on to your 3D TV. (Samsung UN46D7000 3D TV pictured)

3D TV and home theater receivers

If you want to watch 3D TV at home, there are a few must-have pieces. You'll need a TV capable of displaying 3D video, and special 3D glasses for everyone watching. You'll also need a 3D video source, like a 3D Blu-ray player and 3D Blu-ray movie, as well as an HDMI cable to connect it to your system.

So where does a home theater receiver fit in? Well, if you plan on switching your 3D video sources through your receiver, you'll need one capable of passing those 3D video signals on to your TV.

Now, if you don't have a 3D-capable receiver, you could run 3D video signals directly to your TV via HDMI, and run an optical or coaxial digital audio cable to your receiver for surround sound. That's a less-than-ideal solution though.

Having a 3D-capable receiver in your 3D TV system gives you a couple of key benefits. First, you'll still be able to enjoy the convenience of running a single HDMI cable to your TV (as opposed to one from your receiver and one from your Blu-ray player). Second, you'll still be able to get the ultra-high-resolution soundtracks available on Blu-ray discs, like Dolby® TrueHD and DTS-HD™. (Those formats generally require an HDMI connection, so optical or coaxial digital won't cut it.)

Check out our article about 3D TV for more info on what you need and how 3D TV works. And for more info on Blu-ray player connections, see our article about hooking up your Blu-ray player.

The latest digital entertainment options for your receiver

A growing number of receivers offer digital entertainment options that go beyond traditional audio and video sources. With the addition of a few accessories, most models now make it easy to tune in subscription-based satellite radio services, or listen to tunes stored on a portable music player. Some even offer connections for accessing music stored on a PC.

Satellite radio
With its multitude of music, news, talk shows, and sports channels, satellite radio is one of the fastest growing forms of listening entertainment out there. To receive satellite radio, you'll need to purchase an optional tuner and antenna, along with a satellite radio subscription. Satellite radio-ready receivers let you view song titles, artist names, and channel info on their front-panel displays, or even on your TV screen. Plus, you can use the receiver's remote to change stations just as you would with a conventional AM/FM tuner. Check out this article for more info on satellite radio.

Portable MP3 player and iPod® integration

The Onkyo UP-A1 dock allows iPod control through Onkyo receivers.

These days, lots of folks carry their music collection around with them on a portable music player. Many receivers provide a basic front-panel audio input for connecting virtually any portable player. A few even offer a USB port for plugging in USB flash drives loaded with tunes.

iPod owners can take it a step further by using a specially designed dock with a compatible receiver to transform their iPod into a fully integrated A/V component. These handy control docks let you listen to your iPod's music through your audio system and view stored photos or videos on your TV screen. The docks also charge your iPod as it plays, and allow you to control it using the receiver's remote. Check out our article for more info on choosing an iPod dock.

Music from your PC or via the Internet
Some receivers can connect to your home computer network via an Ethernet port, or even a wireless Wi-Fi® connection, to access music files on your PC, or digital music server. You can also get easy access to thousands of Internet radio stations from around the world using your broadband Internet connection. Receivers without this capability can be attached to a network music player or other device that enables this access independently.  (Another way some advanced models let you use the built-in Ethernet port is for setup and control of your receiver — a very convenient option for custom installation.) See our article on Creating a Home Network for more information about networking compatible A/V gear.

Controlling it all

In general, the more you spend on a receiver, the more features its remote will have. All receivers include a remote control that can, at the very least, control other A/V components made by the same manufacturer. But if you'll be mixing and matching brands in your system, you'll probably want to consider a receiver with a multibrand remote control. This type of remote comes pre-loaded with the codes needed to operate other manufacturers' gear and will provide you with easy, centralized operation of all your components.

Higher-end receivers frequently come with a learning remote. You can "teach" a learning remote the less commonly used commands, such as detailed menu operations, that your A/V components' original remotes offered. And you can program it to control a new component in your system that isn't included in the list of pre-loaded codes. Remotes with programmable macros let you execute a series of commands with the press of a single button. Touchscreen LCD remotes give you screens of virtual buttons specific to the component you're currently controlling, for more intuitive operation of your gear. (To find out more about remotes, see Remote Controls: How to Choose.)

A number of receivers with network connectivity also offer free control applications to use with smartphones. Smartphone remote control apps are growing in availability. They let you to use your phone to do everything from adjusting the volume to changing the EQ settings. Apps offer a visually appealing and intuitive interface to control your receiver when connected to Wi-Fi, either directly or via your home network. There are two great advantages to this. Since the control app works through a radio signal rather than infrared (IR), it doesn't depend on line-of-sight to the receiver. Second, the radio signal also lets you have control at a far greater distance, whether it's in a different room or even outside.

Multi-room flexibility

Many home theater receivers are "multi-room" or "multi-zone" capable, which means they can play music in more than one area of your home at the same time. For example, you could enjoy a movie in surround sound in your main room while a housemate listens to a favorite radio station upstairs. Or, you could pipe the audio from the game into the kitchen and out on the deck so you can keep tabs on the score while you cook.

How do you know what the receiver you're considering will do? Take a look at the examples below to get an idea of the capabilities and rear panel connections to look for.

Most multi-room receivers max out at around three rooms. If you'd like to get music in every room of your house, take a more in-depth look at some of the additional options available for adding a wired or wireless multi-room system and powering your multi-room audio system.

Enjoy audio in two areas of your home at the same time
To hear the same sound in two separate places simultaneously, the easiest way to go is a receiver that can power two pairs of speakers at the same time — that is, one with an extra pair of speaker-level (powered) outputs, as opposed to line-level (not powered).

Here's what to look for: Check the back panel for "A" and "B" speaker outputs, as shown in the inset above. In text, you'll often see this capability referred to as "two sets of speaker outputs" or "two main pairs of speakers."

How do I hook it up? Just add a pair of speakers to your kitchen, patio, or anywhere else in your home, and connect them to the "B" speaker outputs — then you can listen in on Sunday's game while you barbecue, or enjoy your favorite CD while you dine.

Listen to stereo music in one room while a different audio source plays in one or two additional rooms at the same time
To listen to two different audio sources in separate areas (or "zones") of your home simultaneously, you can use a stereo receiver that has multi-source/multi-room capability. You'll also need a separate receiver or powered speakers in each additional listening room.

Here's what to look for: Multi-room receivers usually have a line-level (non-powered) output for each additional zone that they can support. The inset above shows a model with "Zone 2" and "Zone 3" line-level audio outputs (as well as composite video outputs for both rooms). Now, just looking at the back panel doesn't tell you whether you can hear different audio sources (or see different video sources) simultaneously in different rooms. To know that, you'll need to look for terms like "dual-zone/dual-source," or "3-room/3-source." You should also read the detailed specs for the receiver, so you can determine which sources can be selected and sent to different areas of your home.

How do I hook it up? You'll need to connect each line-level output to a receiver or pair of powered speakers in your second and third rooms. (You can also use the "A" and "B" speaker outputs for powering speakers in one or two rooms as in the previous example, but you won't be able to listen to different audio sources simultaneously.)

Enjoy surround sound in your home theater room and play music in another room at the same time without using a second receiver
If you want to watch movies with surround sound while a housemate listens to music in another room, you'll need a home theater receiver with multi-source/multi-room capability. Typically, this kind of receiver will have seven channels of amplification to power both your surround sound system and a second stereo audio source elsewhere in your home.

Here's what to look for and how to hook it up: Some 7-channel receivers use five of those channels to power home theater, and let you decide whether to use the remaining two for back surround channels or stereo speakers in a second room. In this case, you'll have to choose in advance whether you want to listen to a 5.1-surround setup and second-room speakers, or power a full 7.1-surround system. Receivers like this will have a label like "surround back/zone 2" on one pair of its speaker outputs.

Other receivers, like the one pictured above, let you alternate easily between using all seven channels for home theater and using two of those channels to power second room speakers. That's because they have separate speaker outputs, usually labeled "zone 2" and "surround back," so you can make permanent connections to both pairs of speakers. Keep in mind that you'll still have to choose where you want to send that power — it'll just be easier for you to switch between the two. [Note: If you want to enjoy full 7.1-channel surround sound and listen to a different audio source in another room at the same time, you'll need a surround receiver with zone 2 line-level outputs (see inset above) and a separate receiver or a pair of powered speakers for your second room.

Watch our short video on multi-room/mult-source audio to understand more about the basics of this cool receiver capability.