What is RT60, and what should it be in a cinema or listening room?

TL;DR: RT60 is the time it takes for sound to decay by 60 dB after the source stops. For a dedicated home cinema or critical listening room, a typical target is around 0.3–0.5 seconds, reasonably even across frequency — and, just as importantly, even on every axis of the room. Too long and dialogue turns muddy; too short or uneven and the room sounds unnatural.

What RT60 actually measures

RT60 (reverberation time) describes how quickly a room stops "ringing." A hard, empty room has a long RT60 — speech smears and detail is lost. Add the right amount of absorption and the decay shortens, restoring clarity and intelligibility.

Typical targets

Room type Typical RT60 target
Dedicated home cinema ~0.3–0.5 s
Critical listening / hi-fi room ~0.3–0.5 s
Multi-purpose media room ~0.4–0.6 s
Recording / control room often lower, ~0.2–0.4 s

These are guideline ranges; the right figure depends on room size and use. What matters as much as the number is consistency.

Why one number isn't enough

A single room-averaged RT60 can hide a room that decays correctly along its length but rings along its width or height. C-ATS targets RT60 on each axis (length, width and height) so the sound holds together as you move between seats. (More: the complete home-cinema guide.)

How you hit the target

Broadband absorption (the C-ATS Reverberation panel) brings the mid/high decay into range; corner-loaded resonance control evens out the low end; reflection control protects imaging. Performance is verified by measurement — see The System. To see a starting package and layout for your own room dimensions, try the free Room Selector.

FAQ

What is a good RT60 for a home cinema?
Around 0.3–0.5 seconds, kept even across frequencies and across the room's three axes.

Can RT60 be too low?
Yes — an over-damped room sounds dead and lifeless. The goal is the right decay, not the shortest.

Does RT60 tell the whole story?
No. Early reflections and low-frequency room modes need separate attention; RT60 is one important metric among several.