New Release - IRIS 1.1

02 June 2015

We are very excited to announce the official release of IRIS 1.1. This has several improvements over version 1.0, including:

Iris Sketchup


  • A "level reference" feature has been added which enables IRIS plots to be compared in magnitude. Previously they were always normalised to the direct sound level.
  • The IRIS plot data can be exported as a text file for visualising in other software, including SketchUp.

SketchUp Integration

  • A custom extension for SketchUp was written which enables IRIS plots to be loaded into a SketchUp model the room.
  • The IRIS plot rays can be extended to the boundaries of the room, which enables a detailed analysis of how the sound field relates to the architecture and form of the space.
  • Time intervals can be selectively hidden or made visible.

Early Lateral Parameters

  • IRIS now measures lateral fraction (LF) and lateral fraction cosine (LFC).
  • IRIS does this by synthesising a virtual figure-of-8 microphone in post processing, with its null aligned with the direct sound direction.
  • This process is much more elegant than the traditional two-microphone technique - a practitioner does not need to worry about matching microphone sensitivities or custom mounting arrangements.
  • LF measurement with IRIS was extensively tested in a laboratory and found to be accurate to within one JND.

Sound Strength Parameters

  • IRIS now measures sound strength and related parameters (G, G Early, G Late, GLL).
  • An IRIS system can be calibrated for sound strength measurement in a diffuse or free field.

Stage Parameters

  • IRIS now meaures stage parameters - ST Early and ST Late.

Waveform Display Enhancements

  • The waveform display can now show the filtered waveform.
  • In the Parameters view the waveform display is annotated with the backwards integrated decay curve.

Import Impulse Response

  • B-format or mono impulse response files (wav file format) can be imported into IRIS.
  • Visualise existing 3-D impulse response measurements.
  • Compare a modelled response (e.g. B-format IR created using room acoustics modelling software) to the equivalent measured response.

Miscellaneous Improvements

  • Level meters in the Record window.
  • Various GUI refinements.
  • Many under-the-hood improvements (to the parameters and IRIS plot calculation process).

This is a free update to all existing IRIS customers, available on the download page. It may be installed alongside version 1.0, but we suggest you uninstall all existing versions first. Older projects will open in IRIS 1.1, but after this they will no longer be compatible with version 1.0.

What people are saying

  • I regard the acoustic designs of Marshall Day Acoustics to be amongst the finest and probably the most innovative in the world.

    Dr Anders Gade, Technical University of Denmark
  • The operation and configuration of IRIS is effortless...

    Sebastià V. Amengual Garí
  • The success of a musical performance depends on the sense of proximity of performer to listener. This sense is mediated largely by the directional properties of the reflected sound field.

    Sir Harold Marshall