Reverberation Time Calculator Formula

Understand the math behind the reverberation time calculator. Each variable explained with a worked example.

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Formulas Used

Reverberation Time (RT60)

rt60 = 0.161 * volume / total_absorption

Variables

VariableDescriptionDefault
volumeRoom Volume(m3)500
total_absorptionTotal Absorption (A)(m2 Sabine)50

How It Works

Sabine Reverberation Time

RT60 is the time for sound to decay by 60 dB after the source stops.

Formula

RT60 = 0.161 V / A

  • *V* = room volume (m3)
  • *A* = total absorption (sum of surface area times absorption coefficient for each surface, in m2 Sabine)
  • 0.161 = constant derived from the speed of sound and the 60 dB decay requirement

    • Concert halls typically aim for 1.5 to 2.0 s; recording studios 0.3 to 0.5 s.

    Worked Example

    Room: 500 m3, total absorption = 50 m2 Sabine.

    volume = 500total_absorption = 50
    1. 01RT60 = 0.161 * V / A
    2. 02RT60 = 0.161 * 500 / 50
    3. 03RT60 = 80.5 / 50
    4. 04RT60 = 1.61 s

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