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Decay, Absorption, and the Limits of RT60 EstimatesInteractive
A Sabine-style RT60 or absorption calculation compares explicitly idealized scenarios; it is never a substitute for measuring a room's actual decay.
MusicReasonResourceDecay, Absorption, and the Limits of RT60 Estimates
RT60 is the time it takes a sound to decay by 60 decibels after its source stops, a standard, widely cited measure of how "live" or "dead" a space sounds. The Sabine formula estimates it from a room's volume and its total absorption, under assumptions no real room fully satisfies.
The Sabine formula, on your own numbers
The formula is RT60 = 0.161 × V / A, where V is room volume in cubic meters and A is total absorption in metric sabins. RT60 Estimator runs this same calculation; Room Treatment Estimator rearranges it to solve for the absorption needed to reach a target RT60 instead.
Diffuse-field assumptions do not hold everywhere
Sabine's formula assumes sound energy is evenly diffused throughout the room and that every surface's absorption behaves the same way across frequency. Real rooms violate both assumptions, especially at low frequencies, where discrete room modes (see Room Modes and Low-Frequency Behavior), not diffuse decay, dominate the room's actual behavior.
An estimate compares scenarios; it does not diagnose a room
Room Treatment Estimator's output (an amount of added absorption) is a comparison between idealized scenarios, not a specific product recommendation or an acoustic diagnosis. A real measurement of an actual room's decay requires instrumentation this browser-based calculator does not have access to.
Where RT60 fits alongside other room questions
Schroeder Frequency Calculator estimates the frequency above which a room's behavior starts resembling the diffuse field Sabine's formula assumes; Speaker Placement Explorer addresses a related but separate question, where to physically put speakers and a listener.
Frequently asked questions
RT60 is the time it takes for a sound to decay by 60 decibels after the source stops, a standard measure of how "live" or "dead" a space sounds. The Sabine formula estimates it from room volume and total absorption.
It assumes sound energy is evenly diffused throughout the room and that every surface's absorption behaves uniformly across frequency, assumptions no real room fully satisfies, especially at low frequencies where room modes (not diffuse decay) dominate.
No. It estimates the additional absorption (in sabins) needed to reach a target RT60 under the same idealized assumptions; translating that number into specific products and placement is outside its scope and stated as such.