It’s the foundation of any serious entertainment set-up, so what are the must-haves in your next AV receiver?

When you’re assembling a home entertainment setup, there’s a lot of kit on your shopping list: display, Blu-ray player, HDD recorder, HDTV tuner, a set of surround speakers and a subwoofer. How on earth are you supposed to control all this stuff?

Fear not: there’s one more device you need, and it’s the most important one in your whole entertainment arsenal. It’s the audio-visual receiver.

Also known as a surround sound receiver, multichannel or home theatre amplifier, the AV receiver’s job is fairly easy to describe: it takes all your audio-video sources – DVD player, pay TV box, games console, PVR – and sends them out to your TV and your speakers. It’s a sort of super-adaptor: you plug everything into it, and the receiver sends the video out through a single cable to your TV, and the audio out through many cables to the speakers in your surround sound system.

When you introduce an AV receiver to your setup, your TV’s remote won’t get much of a workout: volume and source selection will be handled by the receiver’s remote, which also handles the selection of surround formats, audio processing, and video upsampling functionality.

Broadly speaking, the AV receiver’s job has two important aspects: video and audio. Let’s take a look at both in detail.

AV receiver – video must-haves

Most TVs have a limited number of video inputs, especially where HD is concerned. Remember, for HD you need to use HDMI or component cables. A good HDTV will have two or three HDMI inputs, and one or two component.

An AV receiver, on the other hand, will have at least three of each, and may offer even more. This gives you lots of flexibility when it comes to adding sources into your stack: Blu-ray player, PVR, games consoles, a media server, whatever!

Central switching

Selecting which one to use is simple: just hit a button on the AV receiver’s remote. The video signal from that source will be routed through the receiver to your TV.

Since the AV receiver can accept signals from all kinds of sources – both HD and SD – it’s important to connect it to your display using a cable that supports all possible resolutions. The best solution is HDMI. This is a single cable that runs from receiver to TV, and it supports full 1080p. What’s more, because HDMI is digital, you won’t lose any image quality between AV receiver and TV – important if you’ve spent big dollars on a good Blu-ray player!

Upconversion

When it comes to video, AV receivers have one more trick up their sleeves: upscaling. Unlike the automatic ‘stretching’ of a low resolution image to your display by the TV’s own circuitry, the AV receiver adds image information, turning a 576i image into a 1080p one.

It’s not as good as native 1080p from a Blu-ray player, but a good AV receiver will do an excellent job of upconverting, and results will impress.

AV recieiver – audio must-haves

While an AV receiver is an extremely useful tool for video, where it really earns its keep is in the audio department. Indeed, receivers are primarily audio devices, and you can consider video functionality a very useful bonus.

An AV receiver performs as the amplifier for all your music and movie needs, sending audio out to up to eight connected speakers and a subwoofer. If the built-in amplifiers don’t drive your speakers loud enough for your tastes, many AV receivers also provide a set of pre-outs for connecting more powerful amplifiers.

The AV receiver is also what takes the stream of encoded data off a DVD or Blu-ray disc’s Dolby or DTS audio track and decodes it for playback through your speakers. Being the centre of surround sound operations in a home entertainment system, an AV receiver must include both Dolby Digital and DTS surround support, as these formats are present on DVDs and all Blu-ray discs. Ideally, a receiver you buy today should also support the new high resolution versions of these formats, these being Dolby TrueHD and DTS-HD Master Audio. Available only on Blu-ray disc, these make for the ultimate HD audio experience.

Auto calibration

An AV receiver is a complicated piece of kit, and as with all things audio, extremely subtle when it comes to setup. You could spend days trying to get the balance of five, six or eight speakers just right, so good receivers include an auto-calibration function.

This takes the form of a special stereo microphone you plug into the receiver. You then place the microphone in the usual sitting position, and hit Go. The receiver will play a series of tones through the speakers (including some very odd thumping noises from the subwoofer!) and the microphone will measure the balance of how each sound reached it.

Afterwards, the receiver will tweak its output to each speaker by a decibel or two, either up or down. As a result, the particular architectural oddities of your room are overcome, and you’ll enjoy a perfectly balanced surround experience.

Power

Speaking of output, AV receivers have a power rating, in watts. More watts typically equals a higher total volume (although your speakers will affect this), but power output is also about quality, not just noise. Generally, if your receiver offers 100 watts or higher per channel, it’s got the grunt necessary for a cinema-like audio experience. The neighbours will complain!

Then again, if you’re into discreet late-night listening, you can make use of the receiver’s headphone socket. Yes, it bypasses the surround sound capabilities of the device and outputs a stereo signal, but it’s still a very high-quality signal, and you’ll still have all the benefits of switching between sources, video upsampling and the other conveniences of an AV receiver.

Depending on the model, these can include iPod connectivity, with the ability to control the playlist and view artwork from your TV using the AV receiver’s remote; a second zone function for listening to music from, say a CD, via a pair of speakers in one room while surround plays in another; a USB port for connecting a hard drive chock full of songs and photos to be enjoyed via your entertainment system; CEC control for controlling other devices connected over HDMI using just the AV receiver’s remote; circuitry for improving the quality of compressed music, and a network connection for receiving internet radio stations or accessing tunes stored on a remote PC.

Final word

The power, surround support, convenience features and number and type of connections you’ll need from an AV receiver should not be determined by the system you currently have, but on the one you want. Shoot for the maximum your budget will allow in each of the above categories and you’ll land an AV receiver best able to feed your growing home theatre habit into the future.

Whether you’re a first-timer or upgrading your existing AV receiver, look for these features:

  • 3x HDMI inputs – at a minimum!
  • Decoding for major surround sound formats, including new Dolby TrueHD and DTS HD Master Audio Blu-ray
  • Auto room calibration
  • Video upscaling to 1080p
  • A headphone socket