Finding your first reflection points
A first reflection point is where sound from a speaker bounces off a nearby surface and reaches your ears a few milliseconds after the direct sound. That overlap causes comb filtering, which smears detail and shifts the stereo image. Absorb it and the image snaps into focus.
Method 1 — the mirror trick (easiest)
- Sit in your normal listening position.
- Have a helper slide a small mirror flat along one side wall at speaker height.
- Wherever you can see either speaker reflected in the mirror, mark the wall — that is a first reflection point.
- Repeat for the other side wall and for the ceiling (mirror held overhead).
Place a broadband panel centred on each mark. Two side-wall points and one ceiling point are the priority three.
Method 2 — the geometric method
If you're planning before the room is built, the reflection point on a side wall sits proportionally between the speaker and listener, weighted by their distance from that wall. For a centred listener and a speaker close to the side wall, the point lands roughly one-third of the way back from the speaker toward the listener. The panel calculator places these for you in its diagram.
Why it's worth the effort
| Symptom | Likely cause | Fix |
|---|---|---|
| Vague, wide phantom centre | Untreated side reflections | Panels at side first-reflection points |
| Harsh, "phasey" highs | Comb filtering from a hard ceiling | Ceiling cloud at the overhead point |
| Mixes don't translate | Multiple early reflections | Treat all three priority points, then re-check RT60 |
Back to Acoustic Treatment 101 · Plan it with the panel calculator.