Part 3: Power to the receiver
In the third and final part of JOEL KOPPING’s series on how to buy home theatre, he looks at the relationship between amplifier power and how loud a system plays, as well as setting up your system.
In the previous two parts of this series, we looked at the components you’ll need and the decisions you have to make regarding speakers.
Let’s now move on to a few pointers on how to choose an A/V receiver. As always, your choices depend on numerous factors. The first one is just how much power you need.
The power conundrum
Here you have to decide just how loud you want your system to play, and this is a factor of the speakers you’re using and amplifier power.
In theory, more power is better, but power figures are often extremely misleading.
Firstly, there is the PMPO or Peak Music Power Output. This is a meaningless figure that has no basis in electronic reality. Many small theatre-in-a-box systems quote high PMPO power ratings, but we have yet to come across any of these small systems that actually deliver the kind of power they claim.
The next issue is that the relationship between amplifier power and how loud a system plays is not linear. If we want one system to play only twice as loud as another, we need to have TEN times the power. This means that, if you have an A/V receiver that delivers only 50 watts to each speaker, and your neighbour has an A/V receiver that delivers 500 watts to each speaker -assuming the speakers could actually handle the power without burning up – his system would only play twice as loud as yours.
In reality, there will barely be any audible volume difference between an 80 watt per channel or a 100 watt per channel amplifier, assuming both power measurements were made the same way. So don’t get too hung up on buying based on power ratings alone.
As with speakers, quality is the way to go rather than quantity.
Practical requirements
The most important function to look for when deciding on an A/V receiver, if you want high definition audio and video, is the ability to decode those High Definition audio formats.
The next feature to look at is just how many HDMI inputs the receiver has. It’s more convenient to connect HD components such as Blu-ray players, HD PVRs and HD games consoles to your A/V receiver than to your TV. A feature that we’ve started seeing ‚ approvingly ‚ is a front HDMI input. This is convenient when connecting devices that aren’t permanently part of your system(such as HD cameras or your friend’s media server). The presence of this front input means that you don’t need to go digging behind your system when you want to use any of these additional devices.
Video transcoding is a great feature too. This is when your A/V receiver converts old analogue video (from, let’s say, an old DVD player or standard definition DSTV decoder) to digital HDMI. This means that you only need to run one HDMI cable to your TV and not both HDMI and analogue video cables.
A few extra analogue audio inputs for your CD player or old games console would be good to have too.
Something worth considering is looking at an A/V receiver with a Zone 2 output. This usually means that,if you’re using a 5.1 channel speaker system, you can use the last two speaker channels on your 7 channel A/V receiver to send audio from another source to separate speakers. You could, for example, listen to a CD ‚ playing in the CD player connected to your A/V receiver ‚ in your bedroom, while your family is watching a movie in another room.
Additional extras that are nice to have but not mandatory include iPod docks, LAN connections, and USB ports.
As with speakers, quality components will be far more rewarding and for far longer than those that don’t deliver on their printed promises.
Setting it all up
The most important aspect ‚ far more important than what you buy ‚ is how to set everything up.
Many new A/V receivers are supplied with a set-up microphone and can perform auto calibration. This will automatically set speaker levels, distances and sometimes even equalise the system to suit your room. Use this feature.
If your A/V receiver doesn’t do auto calibration, read your manual and follow its instructions on how to set your system up. Trust us: the time spent here will be well worth it.
Final advice.
We haven’t spoken about Blu-ray player: most do a sterling job of delivering digital audio and video. Once again, confirm that the model you choose can deliver High Definition audio formats.
Most name brand receivers perform extremely well, so whichever one you buy should deliver the entertainment goods.
Who you buy from is extremely important, particularly with complex Home theatre systems. It is always worth paying just a little more to get good service and advice.
There is no need to go crazy on cables either and, if dealers want to sell you expensive cables, make them show you the difference these cable make. If you don’t see or hear a difference with more expensive cables, don’t buy them.
Do consider good stands for speakers, as these can make a difference to what you hear.
If possible, try before you buy.
And finally, if you have any other questions, feel free to post them below.