1/3 Octave (Reverberation times only)

Third-octave band filters, responses corresponding to the requirements in IEC1260. Lowest 1/3-octave where calculation is attempted is 40 Hz, highest band depends on the sampling frequency of the measured impulse response. For this bandwidth only reverberation times and strength is generally of interest, and therefore only the reverberation time parameters T30, user defined reverberation time (Tu) and strength (G) can be calculated.

To minimize the influence of the filter response on the reverberation time calculation, the impulse responses are filtered backwards. This greatly improves the accuracy for short decay times at low frequencies.