IRIS 3D Acoustic Impulse Response Gallery

System Schematic
Computer running IRIS drives Motu USB Audio Interface
Interface connects to amplifier/speaker or PA System and TetraMic


Room Under Test
30 second Swept Sine Excitation per Microphone Loc
Data gets processed. The IRIS system visualizes the resulting 3-D impulse response data as a 2-D or 3-D ‘IRIS plot" or "Hedgehog" or Thiell's "Igle"
Impulse Response Time Window

Color Coded Time Periods
0 - 2 ms (red)
15 ms to 50 ms (Green)
50 ms to 200 ms (Blue)
Lateral Energy Fraction LF
Acoustic Parameter:

Early to Late Arrival Energy Ratio ( C80 - dB)
Early Decay Time (EDT)
Reverberation T20, T30
Time of the Centre of Gravity of the Squared Impulse Response (TS - ms)
Early to Total Sound Energy Ratio (D50 - dB)
Peak Signal to Noise Ratio (PSNR - dB)
PPA Box - Mic Amplifier
IRIS Kit
TetraMic & Cable
MOTU 4PRE USB Interface
CBM Attached to MOTU

30 m STP CAT5 Cable

