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Omni critical distance
Estimate where direct and diffuse reverberant energy are equal for an omnidirectional source.
Room volume (m³): 1–1000000; Reverberation time RT60 (s): 0.05–30
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Omni critical distance
Room volume (m³): 1000 Reverberation time RT60 (s): 1
- Critical distance (m)
- 1.802498
- Critical distance (ft)
- 5.913708
For an omnidirectional source (Q = 1), dc ≈ 0.057 √(V/RT60) in metres; feet = metres/0.3048. This rounded diffuse-field approximation assumes a steady source, a reasonably diffuse room and a matching frequency band, occupancy and room condition for V and RT60. Enter measured or independently estimated RT60, not delay or pre-delay. It excludes source directivity, microphone pickup pattern, strong modes, early reflections, background noise and coupled spaces. It is not a near/far-field boundary, a recommended microphone distance, intelligibility, gain-before-feedback or a placement guarantee. Verify the actual direct/reverberant balance at the working position.
Methodology
How it works
For an omnidirectional source (Q = 1), dc ≈ 0.057 √(V/RT60) in metres; feet = metres/0.3048. This rounded diffuse-field approximation assumes a steady source, a reasonably diffuse room and a matching frequency band, occupancy and room condition for V and RT60. Enter measured or independently estimated RT60, not delay or pre-delay. It excludes source directivity, microphone pickup pattern, strong modes, early reflections, background noise and coupled spaces. It is not a near/far-field boundary, a recommended microphone distance, intelligibility, gain-before-feedback or a placement guarantee. Verify the actual direct/reverberant balance at the working position.
Method and assumptions documented by Techrider.live
2026-10-25
Frequently asked questions
Does this tool include a directional loudspeaker or microphone?
No. The source is fixed to Q = 1. Critical distance describes equal direct and reverberant energy, not microphone reach. 1000 m³ and 1 s give about 1.802498 m; keep frequency band and occupancy with the exported estimate.