Setting up speakers in a rectangular room

The following article was written some years ago by George Cardas of Cardas Cables and distributed liberally.

Very precise speaker placement can open up a whole new dimension in listening, so I will outline the system that is becoming the standard of the industry. The Audio Engineering Society’s (AES) standard listening room is a model of the math used in this system and is the room used for illustration. This method will work with any panel or box speaker, in any reasonably sized rectangular room. You may find that you have already positioned your speakers this way by ear.

The AES standard listening room is a Golden Cuboid 10’ x 16’ x 26’. It’s dimensions progress in the Golden Ratio or Fibonacci sequence (5-8-13-21-34…). The three major nodes created within the listening space are indivisible, and therefore will null rather than beat. The math used to create this perfect listening space can also be applied to speaker placement within any listening space.

The key to this formula is the ratio Phi (0.6180339887… to 1 or 1 to 1.6180339887). The three major room nodes are created by the distances: ceiling to floor, sidewall to side wall, and front wall to back wall.

To determine initial speaker placement, multiply ceiling height by 0.618 (10’ x 0.618 = 6.18’) to determine the distance from the rear wall to the centre of the woofer or the acoustic center of a panel.

Then multiply the room width by 0.276 (width divided by 18 x 5) to determine the distance from the sidewall to the centre of the speaker. (16’ divided by 18 x 5 = 4.4’). At this point place the speakers on tiptoes, one in front two in the back. If the speakers are not very heavy, I suggest throwing a bog of lead shot on top of them. Play the system for a few houses and then fine-tune their position. Usually speakers will not have to be moved more than one inch. Don’t forget to damp first reflection points.

I read an article by him concerning using the same "Golden" ratio (.618) when addressing the shelf dimensions for a stereo rack.

What is the golden ratio of your listening room?

cubdog

Here's some info.................

http://www.tnt-audio.com/intervis/cardase.html

Here's some more information on speaker placement.

I've realized this morning that my current speaker placement is similar to the Audio Physics method combined with a touch of Cardas for side wall distance.

- JP

concerning speaker placement, was it Villchur?, that said something to the effect;

".... take all the measurements and do all the test's, then put the speakers where your wife tells you to."

I now realize why I should have remained single.

Jorge