How to set up & calibrate 5.1 / 6.1 / 7.1 surround sound speaker system

Setting up and calibrating a home surround sound system can be a daunting task if you haven't done it before. There are usually 5 or 7 speakers, plus a subwoofer or two. Plugging them all in is one thing, getting them to sound good together is another. This guide should help out anyone who is confused and frustrated about how to calibrate the thing and set them down the road to movie heaven!

The first thing to do is to recognise what it is that you're looking at. Most home theater / cinema systems consist of 5 speakers, a subwoofer and an amplifier / receiver. To set them up properly, you need 3 speakers at the front, one either side of the tv and the centre speaker either directly above or below it, the other two speakers to the side of the sofa, aiming directly at your ears and the subwoofer can go pretty much wherever you want it in the room, although generally you'll get the best results if you place it against a wall or in a corner.

This is how it should look. You don't put the rear speakers behind your head, although they do handle the rear effects. This sort of setup is known as 5.1 surround sound. The 5 refers to the speakers, the .1 refers to the subwoofer. Wiring them up to the amplifier is fairly straightforward, you just have to make sure you connect the + to + and - to - terminals. You need to ideally have the front 3 speakers as close as you can get them to the same height so you don't get a strange effect when effects pan from left to right or vice versa.

This is a 6.1 setup. It's the same as the 5.1 version, but you have an extra channel behind your head which helps with the rear surround effects.

This is how a 7.1 surround sound setup looks. There are two speakers behind your head. This sort of setup has a really good field of surround sound behind and in front of you. This is the way I have my system set up! It does involve a couple more speakers and more wiring, but it is certainly worth it in my opinion.

Now comes the fun part, where you adjust the levels and calibrate the system. The speaker levels need to be set so they are a match for each other. This means they will then compliment each other and one won't be way louder so effects will move around the room properly and sound natural.

There are two ways to do this. If you have a low end system, the home theater in a box sort of setup, then the best way to calibrate is to use an spl meter. These don't cost a lot and make things far easier than trying to calibrate by ear. You need to play a test tone through your receiver one speaker at a time and set each speaker to the same level on the spl meter. This is done from your normal sitting position. As long as they're all the same level relative to each other, it doesn't actually matter too much what that level is, but a commonly used level is 75 db for each speaker in turn. The subwoofer usually under reads on the spl meter due to their inaccuracy at measuring bass tones, so you may need to boost that up a little higher to have it matching the rest of the speakers.

If you have the next level up from an all in one and have a receiver and speakers then you can get better results. Most receivers nowadays have an auto setup system which will calibrate for you. Different manufacturers have different systems, Denon, Onkyo, Marantz receivers have Audyssey, Yamaha have YPAO, Pioneer have MCACC. They basically do the same thing though, although some say that Audyssey is the best of the bunch. Anyway the way they work is that you set up a microphone which is supplied with the receiver at your listening position, the receiver will then play a test tone through each speaker in turn and then calibrate system levels and EQ the sound for you.

There are still a couple of things you need to remember when doing this though. One thing to remember is that you need to make sure that the room is as quiet as possible. Turn off any fans, close the windows etc as you don't want any banging, booming or rumbling from buses driving past to affect the final result.

Set the subwoofer gain control to the middle of the dial. Set the crossover frequency on the subwoofer to maximum.

The easiest way of holding the microphone at the correct height, which is ear level, is with a tripod. These don't cost a lot. Set it up at your main listening position, pointing straight up at the ceiling, then run the auto calibrate routine. A lot of these systems will give you a better result if you take multiple readings, you want to be roughly around the main seating position though as if you try and use different seats it will mess up the final calibration. Get as many readings as possible, usually the system asks you to move the mic 6 or 8 times. The more information it gets, the better the results.

After the receiver has ran through it's auto calibrate routine, then check what level the receiver has set the subwoofer (also known as LFE) level. The subwoofer usually has it's own amplifier, the receiver will try and match the subwoofer to the same level as the rest of the speakers which will usually mean it has to either boost or cut the output level. This will then show up on the receiver. There is only so much this can be cut or boosted, if the receiver is showing -12 or +12 for LFE level after calibration, then it is at it's upper or lower limit. If this has happened, simply adjust the gain on the back of the subwoofer up or down, depending on the reading, then calibrate it again by rerunning the receiver auto calibrate routine. The ideal is to get it as close to 0 as possible, then there is no boosting or cutting between the receiver and the subwoofer, which leads to a minimum of distortion. If it's a few db above or below it's not the end of the world, so you don't need to get too obsessive, but just try and make sure it's not at the top of bottom of its range.

Different rooms affect sounds in different ways so sometimes you may need certain frequencies boosting or cutting. It does this by playing a full frequency range signal, to each speaker, measuring how the room affects the sound then adjusting the output level and also the equalisation of the sound to try and produce what will end up at your ears as a neutral sound.

After you've ran the auto calibrate setup program, then you will need to adjust the crossover and LFE cutoff level. This is fairly straightforward. The standard is to set all of your speakers to small and then set the speakers crossover points to 80hz. The LFE channel for the subwoofer should then be set to 120hz. These are the recommended settings that Audyssey, THX etc recommend. The reason for this is that speakers struggle to reproduce the lowest frequencies you'll get from a soundtrack. If you set them to only play from 80hz upwards, then they don't distort and the sound is cleaner. The subwoofer will take the strain instead and do the job it's designed for, which is creating the low frequency effects.

Now what the receiver will try and do with it's Audyssey, YPAO or whatever system it uses to calibrate, is get the sound in your room as close as it can to a reference sound, in other words how it is supposed to sound. This can be quite a different sound to what you're used to if you've always set up your systems by ear, but if you want it sound how it should, then you should leave it like this. Of course as its your system, if you decide you prefer the bass a bit higher for example, then you're free to do that. This is what is called reference vs preference. The reference sound may not be exactly to your taste straightaway, but you're best to watch a couple of movies before making up your mind so you can get used to it before making a decision to tweak anything. Some people, myself included, prefer a slight boost to the subwoofer level from reference, so I calibrate with the receiver auto calibrate system, then tweak the LFE channel on the receiver afterwards to increase the subwoofer level by 3db. I know this isn't 100% accurate sound reproduction, but it's how I prefer it.

The one thing that you shouldn't do is mess about with the dials on the back of the subwoofer once you've ran calibration. If you are going to do it, then adjust through the receiver.

If you move the speakers or subwoofer, or move the furniture around, then it's a good idea to calibrate again. Other than that, you're done, go and listen to some music or watch some movies!

I hope this guide helps out some people, if you have any questions or comments then please feel free to ask them and I'll help out wherever I can.

Thanks!