Buyer's Guide: AV Receivers
Group Test The first thing to decide is whether you want an AV receiver or if you’ll be happy with just an AV amp. Each will include a multichannel amp (5.1 minimum) and preamp for processing sound and video, but a receiver will include a radio tuner and a connection for a quality aerial. It may also, but not necessarily, include access to Internet radio. All the models included in this round-up are receivers, but don't expect to find DAB among the spec, as it's all AM/FM only.
Wired for sound... and video
Any modern AV amp or receiver will, of course, include HDMI inputs and outputs but it’s worth checking what features are included, since they’re not all the same. The latest HDMI spec, formerly known as 1.4, includes ARC (audio return channel) which allows a similarly equipped TV to send audio info back into the amp and there's standby pass-through, which allows you to access your plugged-in sources without the need to fire up the amp.
One of the recent trends in home cinema is for adaptable speaker placement. Sound processing facilities such as Dolby ProLogic IIz and Audyssey DSX give you the option of replacing or augmenting your surround channels with additional ‘height’ or ‘width’ channels, with some preferring these effects to the more traditional rear speakers in a 7.1 set-up.
Most receivers these days will come with an automatic calibration system to help you with setting up the optimum sound from each of your speakers, often incorporating the dynamics of your room. Not to be confused with Audyssey DSX – the processing which offers additional height and width channels in some receivers – is Audyssey’s Dynamic EQ.
One of several calibration tools available, the Audyssey system uses a microphone plumbed into the AV receiver. The mic is then placed in your listening position(s) while the speakers throw out a series of tones. These signals, picked up by the mic, are then processed to produce the optimum sound balance. You can use these settings as a basis before your start your own selective tweaking or ignore it altogether and just do it all manually.
If you’re likely to be watching standard def DVD or TV (certainly, most of us for a few years to come), 1080p upscaling in your receiver can be well worth having. An HDMI lead from your Sky or other set top box, or direct from your TV will give you the option to upscale to the highest def your screen can handle.