Very precise loudspeaker placement can open up a whole new dimension in listening, so I will outline the system that is becoming the standard of the industry. This standardized listening room is a Golden Cuboid and is the model for the math used in this system. This method will work with any box speaker, in any reasonably sized rectangular room. You may find that you have already positioned your speakers this way by ear.
Active nodes are the main concern when placing loudspeakers in a rectangular room. A node, or the frequency where loudspeakers and parallel walls interact, is proportional to the speaker to the wall distance.
The three most importance nodes, in order of importance, are proportional to the distance between the speaker and:
1. The side wall nearest the speaker
A secondary factor is the loudspeaker-to-loudspeaker time constant.
When you use this Golden Ratio method to set your room up, the speakers are placed so the three nodes progress or differ from one another in Golden Ratio. This eliminates any unison or near unison resonance in the nodes.
Panel or dipole loudspeakers such as Apogees and Magnepans cancel their side waves, so a formula of .618 x the ceiling height can be used for determining placement from the rear wall. Most box loudspeakers radiate low frequencies in all directions thus a formula that places the loudspeaker to rear wall distance at 1.618 the side wall distance should be used.
Loudspeaker Placement, Simply Stated
The distance from the center of the woofer face to the side walls is:
Room Width times .276 (RW x .276)
The distance from the center of the woofer face to the wall behind the speaker is:
Room Width times .447 (RW x .447)
This is all you need to know to place speakers in a symmetrical, rectangular room!
For those who must know more about the various ways to setup your room according to George Cardas, please click here.
Cardas Audio, Ltd.