What Is the Room Acoustic Reverberation Time (RT60) Calculator?
The Room Acoustic Reverberation Time (RT60) Calculator designs acoustic treatments for recording studios, classrooms, and auditoriums.
How Does the Room Acoustic Reverberation Time (RT60) Calculator Work?
It computes the statistical decay of acoustic sound energy using Sabine and Eyring formulations with high-frequency atmospheric air absorption.
Room Acoustic Reverberation Time (RT60) Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
RT_{60, Sabine} = \frac{0.161 V}{A + 4mV}, \quad RT_{60, Eyring} = \frac{0.161 V}{-S \ln(1 - \bar{\alpha}) + 4mV}
Statistical room acoustics decay equations balancing volume sound energy against boundary absorption.
How to Use the Room Acoustic Reverberation Time (RT60) Calculator
- Enter room volume in cubic meters.
- Specify total interior boundary surface area.
- Input the composite average sound absorption coefficient (ᾱ).
Step-by-Step Example Calculation
University Lecture Classroom (250 m³)
Input Values:
roomVolumeM3:250
totalSurfaceAreaM2:280
averageAbsorptionCoeffAlpha:0.18
airAbsorptionCoeffM:0.002
Worked Steps: Eyring RT60 is 0.70 seconds (Sabine: 0.77 s), providing excellent speech intelligibility without acoustic smearing.
Understanding Your Result
RT60 Decay Time: Seconds required for sound to fade by 60 dB.
Acoustic Suitability: Automated classification for speech, orchestral music, or excessive echo.
Factors That Affect the Result
- Larger room volumes increase RT60, requiring more acoustic paneling to control reverberation.
When Should You Use This Calculator?
- Classroom acoustic compliance (ANSI/ASA S12.60), home theater design, podcast studio isolation, and church sanctuary renovations.
Assumptions & Limitations
- Assumes a diffuse sound field where acoustic energy is uniformly distributed throughout the room.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard architectural acoustics method per ISO 3382-2.