TL;DR: A first reflection point is where sound from a speaker bounces once off a surface before reaching your ears. These early reflections arrive just after the direct sound and smear stereo imaging and clarity. Find them with the “mirror trick” and treat the side walls and ceiling (sometimes the floor) symmetrically.
Why early reflections matter
Your ears localise sound from the first wavefront to arrive — the direct sound from the speaker. A reflection arriving a few milliseconds later, from a nearby wall or the ceiling, confuses that cue: the stereo image widens, wanders and loses focus, and dialogue loses clarity. Controlling the first reflection points is the single highest-impact step in most rooms.
The mirror method
Sit in the main listening seat. Have someone slide a small mirror along each side wall; wherever you can see a speaker in the mirror is a first reflection point for that speaker. Repeat for the ceiling. Mark each spot — that's where treatment goes.
Which surfaces to treat
- Side walls — the left/right reflection points for the front speakers.
- Ceiling — the overhead reflection, often overlooked, important for immersive formats.
- Front/rear — depending on layout and speaker type.
Symmetry is non-negotiable
Treat the left and right reflection points identically. Asymmetric treatment pulls the stereo image off-centre — a common cause of a room that "sounds wrong" despite plenty of panels. C-ATS designs side-wall layouts as mirror images, often in a checkerboard pattern so each panel faces a gap.
Reflect or absorb?
You don't always want to kill the reflection — sometimes controlling and scattering it preserves a sense of space. The C-ATS Reflection Control Panel is tuned as a clean reflector for exactly this, while broadband absorption handles overall decay. (See the complete home-cinema guide.)
FAQ
How do I find first reflection points?
Use the mirror trick from the listening seat: where you can see a speaker in a mirror on the wall or ceiling is a first reflection point.
Should I treat both side walls the same?
Yes — symmetry keeps the stereo image centred. Treat left and right identically.
Do I need to treat the ceiling?
Usually yes, especially for Atmos/immersive setups where overhead reflections affect height cues.