Monitor Placement Calculator — Equilateral Triangle Method

The equilateral triangle method places the two monitors and your head at the three points of an equilateral triangle, with 60 degrees between the monitors from the listening position. The distance between monitors equals the distance from each monitor to your ears. This provides optimal stereo imaging.

The 38% rule positions your listening seat at 38% of the ROOM LENGTH (front-to-back) measured from the front wall — the wall behind the monitors — because that point tends to fall between the worst peaks and nulls of the room's length-axis standing waves. It is a starting point, not a strict law: anywhere in roughly the 35–43% band is a sensible search range. It is NOT a side-wall clearance figure and has nothing to do with a percentage of your listening distance.

Monitors should be either flush-mounted in the wall (soffit mounted) or placed at least 50–60cm from the rear (front) wall behind them. Placing a monitor roughly 1/4 wavelength from a boundary causes a deep cancellation null (SBIR), so avoid mid-distances; very close coupling or full soffit mounting avoids it. Rear-ported monitors need more clearance than front-ported designs.

The tweeters should be at ear height when you are in your normal working position. Most engineers sit with ears at about 110-130cm from the floor. Tilting monitors slightly toward your ears is acceptable if exact height matching is not possible.

Ideally no — placing monitors on the desk causes reflections from the desk surface that create comb filtering. Use stands behind/beside the desk, or use isolation pads to decouple the monitors from the desk and tilt them to the correct angle.