Room echo check: how much acoustic treatment does your room need?
Enter your room and its surfaces to see the echo time (RT60), the treatment area that brings it to a home-cinema 0.4 s, and where sound first bounces on its way to your seat.
How much treatment, and where?
An estimate. Echo time uses the Sabine formula with published absorption figures for common building materials (Everest & Pohlmann, Master Handbook of Acoustics) and typical upholstered seats, for a closed room without doors or windows. Treatment is split by type, as an area: bass traps in the 4 corners (2 ft face, floor to ceiling, 100 mm porous), diffusers on the rear wall's ear-height band when your seat is 8 ft or more from it, and 2″ (50 mm) broadband absorption (2″ glass-fibre board figures) for the rest, sized to bring the mid-band to 0.4 s, inside the 0.3–0.5 s home-cinema target. First reflections are where sound from the speakers bounces off the walls and ceiling on its way to your seat (front speakers 2 ft from the screen wall and the side walls; surrounds placed as in our surround planner, at Dolby's angles; tweeters at ear height). Treat those spots first, then spread the rest of the area evenly. Send us your floor plan and we'll mark it up.
Good to know
What echo time should a home cinema have?
0.3 to 0.5 seconds in the mid band (500 Hz–1 kHz). The planner sizes treatment to reach 0.4 s.
How much treatment does a typical room need?
A 20 × 15 × 10 ft room with brick walls, a tile floor, a POP ceiling and 3 seats is about 2.9 s as built; about 330 sq ft of 2″ broadband absorption brings it to 0.4 s.
Every figure here is an estimate from the manufacturer's published specifications and standard room acoustics. Planning a full room? Plan my home theatre · Check compatibility