Convolution Reverb
impulse response · room acoustics · RT60
Physics: Convolution reverb: y(t) = x(t) * h(t), where h(t) = room impulse response. RT60 = time for sound to decay 60 dB. Sabine formula: RT60 = 0.161·V/(S·α), where V=volume, S=surface area, α=absorption coefficient. Concert hall RT60 ≈ 2s; church 3-6s; anechoic room <0.1s. Early reflections (<50ms) add spaciousness without muddiness. Haas effect: sounds arriving within 40ms of direct sound are fused perceptually. FFT-based convolution: O(N log N) vs direct O(N²), enabling real-time use.