Where should you position your monitor loudspeakers?
If you want a good hearty sound engineering laugh, you should visit a video edit suite and see what they do with the audio there. Commonly they will be using speakers that are so inferior you wouldn't even let your dog listen to them. Almost certainly they will be far from their optimum positions - I even once saw one speaker on a high shelf and the other on the floor!
But speaker positioning is known science, and not even rocket science. Anyone can easily place their studio monitor loudspeakers in exactly the right positions.
It comes down to the original theory behind two-channel stereo. Use a coincident crossed pair of microphones to make a recording, or a mixing console with conventional panpots, and you will create a recording where the positions of instruments on the stereo sound 'stage' are represented by their relative levels in the left and right channels. So an instrument that is panned all the way to the left is present in the left channel only; an instrument that is panned all the way to the right is present in the right channel only; and an instrument that is panned center is present at equal levels in both channels. All the in-between positions are in proportion.
Now, if you set up your speakers as two corners of an equilateral triangle (a triangle where all the sides are of the same length), and you sit at the third corner, you will have perfect stereo. It works in theory, it works in practice and it works every time.
Now all we need do is consider the potential flies that may land in the soup...
- If the loudspeakers are close to a wall, then reflections from the wall will in most cases boost the bass unnaturally.
- If the loudspeakers are positioned behind a mixing console, or on the upstand of the console, there will be reflections from the surface of the console that will cause cancellations at certain frequencies. The same applies to reflections from the ceiling above.
- Loudspeakers with two or more drive units should be positioned vertically, not horizontally. This allows the engineer to move freely from side to side without changing the balance of frequencies he or she hears. If they are placed horizontally, then there is only one optimum listening position.
It's easy to wish that all problems in sound engineering were this simple.