Audiophiles spend a lot of money on useless items like cables and wires, but you can make a huge difference in the way your stereo sounds by paying attention to how you position your speakers. There are plenty of articles that go into great detail about placing speakers in a living room environment – you can read three such articles, in increasing complexity: here, here and here – but few of them discuss positioning speakers on a desk. There are a number of points to consider for desktop, or “nearfield,” listening, which is very different from “room” listening.
Here’s a photo of my desk:
Position your speakers at least a foot or two from a wall: If you have a wall behind your desk, don’t put the speakers too close to the wall; if necessary, pull your desk out a foot or two. Sound doesn’t only come out of the front of your speakers, and if speakers are too close to a wall, low frequencies can boom. Try to make sure the speakers are both the same distance from the wall, and try to avoid putting a speaker in the corner of a room, if possible. Don’t put them too close to you either; I find that setting my speakers at the back of my desk is fine. It’s generally not a good idea to have speakers lined up with your monitor.
Raise and/or insulate the speakers: I strongly believe that, for good sound, one should use “real” speakers, not speakers designed for computer listening. (Though powered monitors, such as Audioengine’s A5+ (Amazon.com, Amazon UK) are also a good option.) In this case, your speakers will be fairly large, and it’s best to raise them on stands rather than angle them upward. Speakers of any kind sitting on your desk will cause problems: either from vibrations, or from things in the way on your desk (unless you keep your desk very clear).
To dampen vibrations, use some sort of insulation under the speakers, or use desktop speaker stands such as these from IsoAcoustics (see my review; Amazon.com, Amazon UK). If you do want speakers at the level of your desk, you can use these Audioengine Desktop Speaker Stands to both insulate them and angle them toward your ears (see point 4). (Amazon.com, Amazon UK)
Separate the speakers: You don’t want your speakers just sticking out from the edges of your monitor; spread them as far apart as you can on your desk, ideally about 4-6 feet, for good stereo imaging. Make sure they are equidistant from your head.
Point the speakers toward your ears: To get the best sound, you need to find the right angle for your speakers. They should point toward your ears, but to find out how much, start with the speakers facing straight ahead from your desk. Listen to some music you’re familiar with, then turn them inward a bit, and listen again. Keep doing this until you find the sweet spot. One rule of thumb is that you shouldn’t see the sides of the speakers when you turn your head to look at them; the speakers should more or less be pointed toward your head.
Position the speakers so the tweeters point to the height of your ears: High-frequency sound waves are very short. A 4,000 Hz sound wave is approximately 8.5 cm; that’s shorter than a cigarette. While the sound wave spreads out as it leaves a speaker, higher frequency sound waves spread out much less quickly than lower frequencies. For this reason, you’ll find that, if your tweeters aren’t at the height of your ears, you’ll miss out on much of the high-frequency sounds. This is less of an issue in a living room, but when you’re listening on your desk, the speakers are only a few feet from your ears. If you have small speakers sitting flat on your desk, pointing straight out, you’ll be missing much of the high frequencies when you listen to music.
If you use a sub-woofer, you can put it anywhere you want: In general, since low-frequency sound waves are very long – a 300 Hz wave is about 114 cm, or more than three feet – you can put a sub-woofer anywhere you want. (This is also why you only need a single channel for a sub-woofer; you wouldn’t be able to hear the stereo image because the waves are too long.) Stick it under the desk, on either side, but not too close to a wall or corner, to avoid booming.