Software for measurement and analysis of 3D spatial impulse responses

IRIS is a powerful and user friendly measurement system for capturing and analysing room impulse responses in 3D.  In addition to the evaluation of room acoustic parameters according to DIN EN ISO 3382, IRIS can be used to analyze individual reflections, their direction and sound intensity. IRIS is currently available in version 1.1 and is developed by Marshall Day Acoustics.


  • Measurement of 3D room impulse responses (Ambisonic B format)
  • Three-dimensional representation of reflections, their direction and intensity
  • Automatic evaluation of the OMNI impulse response and room acoustic parameters according to DIN EN ISO 3382
  • Reverberation time T20/T30
  • Early decay time EDT
  • Focal time Ts
  • Clarity measure C80 and degree of clarity D50
  • Seitenschallgrad LF und LFC (siehe auch: Protheroe D., Day C. “Validation of lateral fraction results in room acoustic measurements,” Proceedings of Inter-noise, 2014)
  • Thickness G, G Early, G Late & GL (incl. calibration menu)
  • Stage parameter ST Early and ST Late
  • Automatic division and color marking of reflections into different time windows
  • When selecting a reflection in the 3D window, the corresponding time window is marked in the impulse response.
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  • If a time window is selected in the impulse response, the corresponding reflection is marked in the 3D window.
  • Automatic recognition of the starting point of the impulse response and possibility of correction
  • Easy to use and clearly structured user interface
  • Export IRIS plots to SketchUp

Components of the system:

  • IRIS software, incl. USB dongle
  • Tetrahedral microphone (Core Sound TetraMic)
  • Calibrated USB audio interface (Motu 4pre)
  • 30m microphone cable (CAT5E STP), incl. adapter for phantom power and microphone cable
  • Transport case (Pelicase)

Further information, historical background to this measurement method as well as some case studies can be found on the official IRIS Homepage.

Any questions?

Just give us a call or write an e-mail!