— RT60 Calculator - Corporate AV
Conference room speech shell, 144 m3, RT60 0.12 s
Problem. An 8 x 6 x 3 m conference room dressed on every surface - carpet floor, full fabric walls, full acoustic-panel ceiling - needs checking against the speech reverberation target. The question is whether treating every surface actually lands the room where a speech design wants it.
Answer. With 144 m3 of volume, roughly 119 sabins of absorption and a mean absorption of about 0.66, the tool uses the Eyring model and returns RT60 of about 0.12 s. The target band for 144 m3 is 0.50-0.70 s, so withinTarget is false: at 0.12 s the room sits well below the band and is over-damped, not in band.
02 / In depth
How this preset reads — the engineering view.
The geometry gives 180 m2 of total surface across a 144 m3 volume. The floor is 48 m2 of carpet at a 1 kHz coefficient of 0.50 for 24 sabins, the ceiling 48 m2 of acoustic panel at 0.85 for 40.8 sabins, and the walls 84 m2 of fabric at 0.65 for 54.6 sabins - about 119 sabins in total.
Because the mean absorption reaches roughly 0.66, well above the 0.2 point where Sabine loses accuracy, the tool switches to the Eyring form and reports RT60 of about 0.12 s. That is a very dry, deliberately over-damped result.
The 144 m3 volume places the room in the office and classroom band of 0.50-0.70 s. At 0.12 s the figure is below the band, so withinTarget is false - this is reported honestly as too dead for speech, not as a room sitting comfortably in target.
The recommended added absorber is 0 m2. There is nothing to add; if anything the room is over-treated. The lesson is that dressing carpet, full fabric walls and a full panel ceiling all at once overshoots the speech target - a real design would leave some surfaces reflective to land inside 0.50-0.70 s.
What this preset deliberately does not solve
- withinTarget is false because 0.12 s is below the band, not in it.
- Added absorber is 0 m2; this shell is over-treated for speech.
- Single 1 kHz band only; low-frequency behaviour is not modelled.
How this preset differs from its siblings
This preset is the over-damped, fully-treated small room: 144 m3, about 119 sabins, mean absorption 0.66, Eyring model, RT60 0.12 s and below the 0.50-0.70 s band. The auditorium sibling is the opposite failure - a bare hard shell of 1,296 m3 with only about 72 sabins, mean absorption 0.09, Sabine model and RT60 2.9 s above its 1.60-2.20 s band. One shows treating every surface overshoots into dead; the other shows an untreated shell rings too live and needs roughly 45 m2 of absorber added.
03 / Hydrated calculator
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Brief us on the project — with this configuration.
Presets are a typology starting point. The brief wizard captures the room geometry, programme and constraints we need to translate this configuration into a real design.