Acoustic Treatment 101
Acoustic treatment controls how sound behaves inside a room (reflections, reverberation, bass build-up). It is not soundproofing, which stops sound leaving or entering. This guide covers treatment, in the order that gives the most improvement per panel.
The order that matters
Beginners often cover the walls with thin foam and wonder why the bass is still a mess. The fix is priority: spend your first money where the energy is highest.
Priority decision table
| Priority | Where | What | Why |
|---|---|---|---|
| 1 | 4 vertical corners | Floor-to-ceiling broadband bass traps | Bass pressure peaks in corners; this is the biggest single win. |
| 2 | Side walls + ceiling, first reflection points | 50–100 mm broadband panels | Kills comb filtering that smears the stereo image. |
| 3 | Front wall (behind speakers) | Broadband panels | Tightens low-mids around the monitors. |
| 4 | Remaining wall area | Broadband panels to hit coverage target | Brings overall RT60 into range. |
| 5 | Rear wall | Absorption or diffusion | Controls slap-back; diffusion keeps the room from sounding dead. |
Thin (25 mm) foam barely touches anything below ~500 Hz. For broadband control use
50–100 mm mineral wool or rigid fibreglass — see the
absorption database to compare.
Step-by-step
- Measure. Get length, width, height. Run the room mode calculator — a poor ratio means you'll lean harder on bass traps.
- Corners first. Four floor-to-ceiling bass traps. The panel calculator assumes this.
- First reflections. Use the mirror trick (next guide) to find them.
- Hit your coverage target. 30–40% of wall+ceiling for mixing; less for casual use. The calculator gives you the number.
- Verify with RT60. Re-run the RT60 calculator with your added panels as surfaces and check you're in the target band.
How much is enough?
More absorption is not always better. Over-treat and the room sounds unnaturally dead and fatiguing. Aim for the target RT60 band for your use-case rather than the lowest possible number — the calculator shows whether you're "too dead", "on target", or "too live".