So you’ve bought that brand new home theatre surround sound system and taken it home in eager anticipation of sitting right down and watching the complementary Iron Man blu-ray they gave you at the shop. Boy, those sound effects are sure going to be awesome in full 5.1 sound!
But wait a minute, there’s an awful lot of speakers and wires here, an awful lot of connecting and setting up to do. Bummer! Iron Man’s going to have to wait a while.
While it’s true that a surround sound system takes a little effort and time to set up, it’s not really as bad as that mess of wires makes it look. There are essentially three areas you need to address: connection, speaker placement and volume level. Take them one at a time and you’ll be battling the baddies with Robert Downey Jr. in no time.
In a 5.1 surround sound system there are five speakers (front left, front right, centre, rear left and rear right) and one subwoofer. Each of the speakers must be connected to your receiver. The receiver is the box that decodes the sound signal and sends it to the appropriate speakers – often it will be built into your DVD player.
As movies have their sound separated into a number of different channels, and as each of these channels exits from its appropriate output on the receiver, it is essential that you connect the correct speaker to the correct output on the back of your receiver. Connecting the left rear speaker, say, to the centre output will result in the actors constantly talking behind your back (as the dialogue channel is always routed by the receiver to the centre output).
As you connect each speaker, label it with its designation (LR, RR, C etc.) – post-it notes are great for this. Labelling speakers at this point in the process will save you a lot of time when you begin to place them around the room.
Once you’ve connected all your speakers, you need to place them appropriately. Speaker placement will vary according to the size of the room, its acoustics and your personal preferences. However, there are certain general rules you can follow to get a good starting point.
Place the centre speaker vertically in line with your TV. It’s generally best if the speaker sits just above the top of your TV, preferably on a shelf or speaker stand. There’s nothing to stop you placing it beneath the TV if you prefer the sound, but you’ll almost certainly lose some clarity as the sound waves are eaten up by carpet, or bounce towards the ceiling off harder floors.
The left front and right front speakers should be placed on either side of the TV and in line with it. If you have the room, they should be about 4 meters apart from each other.
Another way to think of front speaker placement is to imagine where you sit when you watch the TV as the apex of a triangle. The other two points of the triangle are the left and right front speakers and they should form an angle of between 45 degrees and 60 degrees with you (i.e. each one will be between 22.5 and 30 degrees to either side of you).
Place the two rear speakers behind your seating position and 60 cm above ear level if possible. Angle the speakers so that they face forwards (i.e. towards the TV), not towards your ears. The rear speakers are generally designed to handle ambient noise and you won’t get a good surround effect if they are pointed right at you.
The subwoofer handles the deep bass frequencies and is responsible for the rumbling earthquake and explosion effects that make action movies so thrilling. The good thing about these frequencies is that they are non-directional, so you have a lot of leeway as to where you can place your subwoofer.
As a starting point, try placing the subwoofer in front of your seating position, against the wall where the TV is. Try it in various positions around the room until you get the effect you prefer. Note: placing a subwoofer in a corner can sometimes make bass tones too boomy.
With the speakers all connected and satisfactorily placed it’s time to adjust their various volume levels.
Some receivers have an setup program which automates this process, but often you’ll end up doing it manually in order to suit your own listening preferences.
While playing a DVD that is representative of the movies you like to watch, adjust the centre speaker volume so that the dialogue is clear and comfortable to listen to.
Adjust the front left and right speakers (predominantly sound effects and music) so that they blend seamlessly with the dialogue from the centre speaker.
Set the volume on the rear speakers so that the sounds from these speakers are perceived, rather than actively heard. The rear speakers are intended give a sense of space and realism, not to continually blast out distracting side notes.
The subwoofer should give you a solid foundation of deep bass tones, but it should not overpower or distort the sound from the front or rear speakers. Start with the subwoofer turned down low, watch a few scenes in your test movie, then gradually increase its volume until you achieve the required amount of bass.
Your surround sound system is now set up and you can sit down, grab a well-earned supply of snacks, fight evil with Iron Man and enjoy yourself in a realistic sound environment. It’s worth remembering, though, that sound varies from movie to movie and the setup you’ve just gone through is really just a base from which to work and you may need to make ongoing volume adjustments in order to maintain your listening pleasure.
To learn more about surround sound speaker placement check out this video.