5. What to look for in an AV Receiver
While any system is only as good as its weakest link, your AV Receiver is one seriously important bit. It's crucial that it does everything you want it to now, and for the foreseeable future.
If you're worried about overlooking something important, we'd recommend you make a list. Still, it can be easy to get caught up in the excitement of purchasing a home theatre and forget something. That's why many people prefer the security of our three month take-home guarantee.
How many speakers can I run off an AV receiver?
If you're planning a 5.1 channel surround sound system (two front speakers, two rear speakers, a centre-channel speaker and a subwoofer) you'll need at least a 5.1 channel receiver. That is, a receiver with five amplifiers on board – one for each speaker (subwoofers generally have their own amplification built-in so don't need help from the receiver). Most receivers are at least 6.1 these days anyway.
Is it powerful enough to drive your speakers?
The most hazardous thing for speakers is an underpowered amplifier. Better to have a bit more power than you need to drive the speakers you buy. If the speakers you buy are rated at 50 watts, get an amplifier that can deliver at least 50 watts to each speaker it has to drive (that would be described as 5 x 50 watts for a 5 channel receiver).
Is it easy to use?
Some AV Receivers are more complicated to use than others. Here are some good indicators that any system you're playing with is easy to use:
* When you play a DVD disc, it automatically detects and switches to the appropriate surround sound decoding (Dolby Digital, Pro Logic IIx etc). Without this you'll have to do it manually
* Switching between sources (DVD, CD player, game console etc) can be done by turning one knob on the receiver or with the press of a button on the remote. Some poorly planned AV Receivers require you to access onscreen menus (and other lengthy procedures) to perform frequent, basic tasks
* The remote control is well laid out and able to control all – or at least most – of your other devices. Using several remotes can be a nightmare – especially if one is lost
* The system can automatically calibrate your speakers. If not, it can take a lot of manual adjusting to get the sound right. This can seem complex when your system is new.
What surround sound formats must it support?
A movie soundtrack may be stored on a DVD disc in a number of different formats. Your AV Receiver needs to know how to decode each format so that it sends the right information to the right speakers so you hear the movie the way it's supposed to be heard.
All AV Receivers will support Dolby Digital and DTS. Both of these formats are 5.1 channel surround sound formats. That means sound is broken into five speaker channels plus one subwoofer channel. If you're looking at a 6.1 channel speaker system, you'll need an AV Receiver which supports 6.1 channels and also decodes in Dolby Digital EX and DTS-ES. These two extra formats are specially designed for 6.1 channel sound and will make full use of the extra sound channel. You will still be able to play 5.1 channel discs perfectly.
All AV Receivers can convert stereo music or TV signals into multi-channel surround sound. They use Dolby Pro logic or Dolby Pro Logic IIx decoding to do this. Dolby Pro Logic IIx is a newer format and offers better results.
Does it have all the connections you need?
Your AV Receiver is the hub of your home theatre system. The back end is a bewildering array of connectors – either inputs or outputs. Inputs receive information from other components such as a DVD player for processing by the receiver. Outputs send information from the receiver to other components like speakers.
The inputs and outputs you need depend on the number of components you have (or anticipate having) and the connections each of those components has.
Here is a general breakdown of the types of inputs and outputs and the quality of signal they provide:
Sound input/output connection:
Stereo RCA: Analogue sound signal (Good)
Coaxial/optical: Digital sound signal (Better)
HDMI: Digital sound and image signal in one cable (Best)
Image input/output connection:
Composite: Analogue image signal (Good)
S-Video: Analogue image signal (Better)
Component: Analogue image signal (Better still)
DVI: Digital image signal (Best)
HDMI: Digital sound and image signal in one cable (Best)
What sound quality can I expect from my AV Receiver?
Although your AV Receiver doesn't actually make a sound itself, it does process the sound signals sent to it (by your DVD player etc) and pass them on to your speakers. The way that it processes sound has a big influence on everything you hear.
For the highest quality surround sound – and to take full advantage of the Dolby Digital and DTS formats – you must connect your DVD player to your AV Receiver via a digital cable (optical, coaxial or HDMI). This is where the 'digital to analogue converter' (DAC) in your AV Receiver comes into play.
Why does your 'digital to analogue converter' (DAC) matter so much?
The quality of the DAC in your AV Receiver plays a big part in the quality of sound you'll hear. As your AV Receiver receives digital sound information from your DVD player, your DAC converts that information into analogue sound signals which are passed on to the speakers. As a general rule of thumb, look for 24-bit 192MHz DACs if you want a cinema quality (or better) home theatre experience. Lower numbers (e.g. 12-bit 96MHz) mean lower quality sound.
What image quality can I expect from my AV Receiver?
Your AV receiver is not involved in image processing. That's determined by the quality of your DVD player, screen and cables. However if your home theatre is set up so the image signal has to pass through your AV receiver on its way to the screen, make sure your receiver can connect to the kind of cable you'll need to use if you want a good quality image (see cables for a discussion on image quality)
Is it multi-room capable?
A growing number of AV Receivers will let you enjoy different music and movies in different rooms at the same time – from the one AV Receiver. There are a few more considerations to take into account with multi-room applications, but if you understand the basics of home theatre then you won't have any trouble picking it all up. If a multi-room setup appeals to you, you might like to read our section dedicated to choosing a multi-room system.
Your system is only as good as its weakest link
Your AV Receiver is just one part of an entertainment team. Like any team, your home theatre system will be limited by its weakest member. Keep that in mind as you shop for an AV Receiver as well as your other components.
After you've selected your speakers and your AV Receiver, the next biggest decision you'll face is choosing the right sized screen. Plain and simple… you can't bring that cinema-like ambience into your home without a big screen.