Correct placement of any loudspeaker, as well as proper acoustic treatment of the listening room, is critical in any listening room. We can't emphasize enough that you'll never enjoy the sound you paid for without careful attention to the environment in which you and your system reside. For a detailed discussion of both the theoretical and practical issues, please visit Richard Hardesty's website and read issue #2 of his Audio Perfectionist Journal -- Hey, Kids, it's free!
For a number of years, we experimented with several software applications designed to aid in speaker placement and room treatment. These included the RPG Room Optimizer, CARA, The Listening Room, and Visual Ears. However, in setting up our latest room, we discovered that a combination of the "Rule of Fifths" and the Golden Ratio yielded the best results. In fact, you can try this at home using only a tape measure, pen, paper, and a calculator. While we can't guaranty that this will work with all loudspeaker systems, the cost is only a few minutes of your time.
In applying these principals, the prime objective is to create a Golden Rectangle inside your room, place the listener in the center of the rectangle at one end and place the loudspeakers in opposite corners at the other end. The Golden Ratio of 1:1.618 is the same formula that was originally used to design the EP-1 cabinet and is very effective in cancelling out the sonic reflections which create aural peaks and valleys.
To begin, measure your room to the nearest 1/4" or centimeter (the example shown below is my personal listening room). Draw a line down the center lengthwise and divide the long side into five equal parts:
Next, multiply one of the fifths by 3. This dimension will be the long side of the Golden Rectangle:
Now, take the 3/5ths of the room length that you've just calculated and divide by 1.618 (the Golden Constant). This will be the short side of the rectangle:
Divide the short side that you've just calculated by 2. This is the distance (on either side) from the center line to the long side of the rectangle:
Finally, position the rectangle so that the short sides are 1/5 of the way in from both the front and rear walls and place the listener and speakers accordingly:
We like to toe the speakers in slightly (about 10° back from the front plane), so that from the prime listening position, their sides are no longer visible.
Keep in mind that while this technique should work in theory, the presence of furniture, windows, doorways, and other features unique to your room, may alter the final locations. Sometimes only an inch or two of repositioning along any given axis is all that's needed to bring everything into balance. Ideally, success will be measured by the degree to which the audio system disappears, leaving you to enjoy the performance without distraction.