Speaker Placement Optimizer
This speaker placement optimizer turns your room size into a proven starting layout: the 38% listening position, an equilateral stereo triangle, speaker separation, side- and front-wall distances, toe-in, and where to put the subwoofer — with a top-down diagram.
ℹ These are well-known rules of thumb, not laws. They assume a rectangular room with the speakers on the front (short) wall, firing down the length, and a symmetric setup. Left/right symmetry matters most — keep each speaker the same distance from its side wall. Rooms, speakers and tastes vary, so treat this as a great place to start and then trust your ears (and a measurement — see the Room Frequency Analyzer). All maths run in your browser.
How It Works
The calculator places your listening seat at 38% of the room length from the front wall — a position (popularised by George Cardas) that tends to sit between the worst low-frequency modal peaks and nulls along the length of the room. This 38% rule is the most widely cited starting point for hi-fi setup and home studio monitoring alike. It then builds an equilateral stereo triangle: the distance between the two speakers equals the distance from each speaker to your ears, which works out to about 30° of toe-in when you aim the speakers at your head. From your chosen speaker-to-front-wall distance it also reports the SBIR (speaker-boundary interference) cancellation frequency, f = c / (4·d), where a reflection off the wall behind the speaker arrives a half-wavelength late and partially cancels — one of the biggest causes of a bass suck-out in home studios and listening rooms alike.
Two things matter more than hitting these numbers exactly. First, symmetry: the left and right speakers must be the same distance from their nearest side wall, or the stereo image and bass response will differ side-to-side. Second, your room’s modes: the 38% seat and the front-wall distance interact with axial standing waves (length, width, and height modes), so confirm the result by ear and, ideally, with a measurement tool such as the room mode calculator. Use the diagram as a map, set it up, then nudge the seat and speakers a few centimetres at a time while listening to a familiar bass-heavy track.
The first reflection points on the side walls are where the earliest delayed copies of the direct sound arrive at your ears and smear the stereo image. Once speakers are in their approximate positions, mark the side-wall reflection points by using a mirror: sit in the listening seat and have a helper slide the mirror along each side wall until you can see a speaker in it — that is the first reflection point to treat with acoustic absorption or diffusion. Similarly, the ceiling reflection point sits roughly halfway between your speakers and your seat. Absorbing or diffusing these three early reflections is typically the biggest single improvement you can make after optimising placement. Subwoofer placement is a separate step: a corner maximises output but energises every room mode, while positioning the sub along the front wall (offset from centre) is usually a better starting point for balanced bass. For near-field desktop monitoring, the same equilateral-triangle principle applies but at much shorter distances (often 0.6–1 m), where the room’s contribution is far less dominant.