Reverb Time Calculator — RT60 Sabine & Eyring

RT60 is the time it takes for sound in a room to decay by 60 dB after the source stops. It is the standard measure of how "reverberant" or "live" a room sounds. A concert hall might have an RT60 of 1.5-2.5 seconds, while a recording studio control room typically targets 0.3-0.5 seconds.

The Sabine equation assumes low absorption and works well for live rooms (average absorption coefficient below 0.2). The Eyring equation accounts for high absorption and gives more accurate results for well-treated rooms. For very absorbent rooms, Sabine overestimates the RT60.

For a home studio control room, aim for an RT60 of 0.3-0.5 seconds across the mid and high frequencies. Bass frequencies will naturally have a longer decay time. Professional studios often aim for a flat decay curve using calibrated bass trapping.

The absorption coefficient (α) ranges from 0 (perfectly reflective) to 1 (perfectly absorptive). Concrete walls have α ≈ 0.02, plasterboard ≈ 0.05, carpet ≈ 0.30, and thick acoustic foam ≈ 0.80. The average α for the room is the total absorption divided by the total surface area.