In Part 2 of the Audiophile 101 series we discussed rooms and speaker positioning. We will now discuss the listening position and the importance of the 38% Rule. In many online audiophile forums and articles you will run across people discussing the “rule of thirds” in relation to speaker positioning. While this may offer some benefits under certain conditions, it isn’t really a rule at all. The most likely source of this supposed audio rule is a misunderstanding of the 38% rule used in the design of recording studios.
The 38% Rule defines the optimum listening position in any room by predicting the points where standing waves will be at a minimum. It states that there are two points in every room where standing waves are at a minimum. These points are at 38% of the length of the room from the rear wall and 38% of the distance from the front wall. In recording studios the point from the front wall is used because the monitors are close to the engineer, but in most home applications it will be 38% from the rear wall. If you refer back to what you learned in Part 2, you will realize that the 38% Rule is a more clearly defined form of the 36″ placement guidelines. When used in conjunction with the equilateral triangle positioning instructions it also defines where to place your speakers in the room for optimum performance.