Calculate how long sound takes to decay in your room. Understand your room's reverberation characteristics by octave band.
Free room analysis — no account needed
RT60 (reverberation time) is the time it takes for sound to decrease by 60 decibels after the source stops. It's the standard measurement for how "live" or "dead" a room sounds. A concert hall might have an RT60 of 1.5–2.0 seconds, while a recording studio control room targets 0.2–0.4 seconds. For home listening rooms, 0.3–0.6 seconds provides a good balance between clarity and naturalness.
Atuund computes RT60 using both the Sabine and Eyring equations. The Sabine formula (RT60 = 0.161V/A) works well for rooms with low absorption, while the Eyring method is more accurate for rooms with significant acoustic treatment. Both depend on room volume and the total absorption of all surfaces — walls, floor, ceiling, and any treatments you've added.
Too much reverberation masks detail in music and makes speech intelligible. Too little makes the room feel uncomfortably dead and unnatural. Getting RT60 right is about matching the room to its purpose. For critical listening and home theater, shorter reverberation times (0.3–0.5s) preserve transient detail. For casual listening or music practice, slightly longer times (0.5–0.8s) can feel more natural.
Measured RT60 uses a loud impulse (like a balloon pop or starter pistol) and a calibrated microphone to record the actual decay. Calculated RT60 uses room dimensions, surface areas, and absorption coefficients for each material. Atuund calculates RT60 from your room geometry and default materials, giving you a useful estimate without any equipment.
Most acoustic guidelines recommend 0.3–0.6 seconds for home listening rooms and home theaters. Studios and control rooms target the lower end (0.2–0.4s) for accuracy. Living rooms used casually for music often land around 0.5–0.7s naturally, which is perfectly fine for most listeners.
Add absorptive materials: thick curtains, upholstered furniture, bookshelves, carpet, and purpose-built acoustic panels. Absorption is most effective when placed at first reflection points and room corners. Atuund's free analysis shows your room's RT60 by octave band so you can see which frequencies need the most treatment.
Atuund uses finite element method (FEM) modal analysis to model room acoustics. Built for hi-fi enthusiasts, home theater builders, and anyone who wants better sound from their speakers.