Studio Monitor Placement Calculator

Where you put the speakers has a larger effect on the sound than the price of the speakers. Stereo recordings are made on the assumption that you sit in the right place, with the speakers placed symmetrically. In the right layout the singer appears in a fixed point between them and the instruments stay still. The calculator turns the usual rules into numbers for your room.

The listening triangle

The classic arrangement is an equilateral triangle: the two speakers and your head are at its corners. The distance between the speakers equals the distance from each speaker to your ears, and each speaker is angled in by 30 degrees so that it points at your head. This gives a stereo image that is stable without being narrow. A wider angle weakens the centre; a narrower one collapses the image.

A worked example

Press Sample: a room 5 metres long and 4 metres wide, the speakers 0.5 m from the front wall, 1.6 m apart, and at least 0.5 m from the side walls. With the spacing of 1.6 m, each speaker is 1.6 m from your ears. The height of the triangle is 1.6 × 0.866 = 1.39 m, so the listening position is 1.89 m from the front wall and 3.11 m from the back wall. Each speaker is 1.20 m from its side wall, and turned in by 30°. The 38 percent rule would put you 1.9 m from the front wall, which needs a spacing of 1.62 m, and the button Use the 38% spacing sets that.

The 38 percent rule

Room modes tend to cause the worst peaks and dips of bass in the middle of the room and at the walls. Sitting about 38 percent of the way along the room’s length keeps you away from both. It is a rule of thumb that works in many rectangular rooms and can be tested by ear. The page shows the spacing that would put you there, with the speakers in the triangle, and lets you use it with one click.

Distances and warnings

The calculator lists the distance between the speakers, from the speakers to your ears, from the front and back walls, from the side walls and the toe-in angle. It shows a warning when the speakers are closer to the side walls than the clearance you set, when the listening position is within 0.3 m of the back wall where bass builds up, and when the listener would sit outside the room. The triangle is drawn to scale in a plan view, with the front wall at the top. Moving the speakers away from the front wall and the corners usually reduces boundary boom.

Beyond the numbers

Put the tweeters at ear height and keep the left and right sides of the room as alike as possible, with the desk centred. Do not sit against the back wall, where bass builds up. Try small changes and listen to a familiar recording. A measurement with a microphone confirms what you hear, and treatment, such as absorbers at the first reflection points, makes the position less critical.

Edge cases

A narrow room may leave no space for the speakers to be spaced as wide as the triangle needs, and the side-wall warning will tell you. Nearfield monitors on a desk follow the same geometry at a smaller scale. For home cinema, the surround positions are separate. If the room is not a rectangle, use the longest clear wall.

Limits

This is geometry and a rule of thumb. It does not know your speakers’ radiation pattern, your furniture or your room’s absorption. It treats the room as rectangular, and the results are starting positions.

Related tools

• Room Modes Calculator shows which bass frequencies the room will exaggerate.
• Sound Level Meter compares levels at different positions.
• Speaker Test checks that left and right channels are correct.
• Tone Generator plays test tones for listening.