What are first reflection points?

First reflection points are the spots on walls and ceiling where sound from your monitors bounces directly to your ears. These reflections arrive within a few milliseconds of the direct sound, causing comb filtering and smearing the stereo image. Treating these points is the highest priority for mixing rooms.

How do I find reflection points with a mirror?

Sit in your listening position. Have someone hold a mirror flat against the wall and slide it along. When you can see a monitor reflected in the mirror, that is a first reflection point. Mark it and place an absorber there. Do this for both side walls, the ceiling and the rear wall.

Should I absorb or diffuse at reflection points?

For side walls and ceiling: absorption is generally preferred to eliminate early reflections cleanly. For the rear wall: diffusion can work well, preserving some sense of space while preventing flutter echoes. A combination of both is common in professional studios.

How large should the treatment panel be at each reflection point?

At least 60cm × 120cm (2 × 4 feet) to be effective across a broad frequency range. Larger panels provide better coverage since reflection points shift slightly with head movement. Centre the panel on the calculated reflection point.

Reflection Point Calculator — First Reflection Treatment

Find first reflection points on walls and ceiling for acoustic treatment placement.

Monitor to Side Wall

Perpendicular distance from each monitor to the nearest side wall

Listener to Side Wall

Perpendicular distance from the centre of your head to the nearest side wall

Listening Distance

Front-to-back distance from the monitor plane to your ears at the mix position

Ceiling Height

Floor-to-ceiling height of the room

Ear Height

Height of your ears above the floor at the mix position

Monitor Tweeter Height

Height of the monitor tweeter above the floor

How We Calculate This

Side Wall Reflection Point

Distance from monitor = (monitor-to-wall / (monitor-to-wall + listener-to-wall)) × listening distance

This uses similar triangles — the reflection obeys the law of reflection (angle of incidence = angle of reflection).

Ceiling Reflection Point

Same principle applied vertically, using the distances from monitor and ear to the ceiling.

Rear Wall

The rear-wall first reflection is simply the wall surface directly behind your head, so it has no geometric point to solve. The rear-wall figure shown is a rule-of-thumb treatment zone (a chosen fraction of your listening distance behind the mix position), not a calculated reflection point — use it as a placement guide.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard formulas. Always verify results for critical applications.