Professional audio tools
for use in broadcast

  • The name ISOSTEM stands for innovative audio tools for professional use in the fields of broadcasting, production and post production. The tools support you in creating and editing radio programs and music productions, always taking the latest trends and standards into account.
  • The spread of HDTV provides broadcasters with the challenge so send their program permanently in 5.1 surround sound. As a great deal of the archive material is only available in stereo, the material must be converted into surround sound. ISOSTEM Upmix offers the perfect solution for this situation.
  • With the introduction of the directive EBU R 128, which defines the level control of radio and television to equalize the loudness between programs and to avoid large loudness differences, new suitable measurement and correction instruments were necessary. The ISOSTEM Loudness Ranger has been developed precisely for this application.


ISOSTEM Upmix creates an outstanding surround sound from stereo signals in real time, without altering the original signal. It is the only upmix system on the market, which generates a stereo signal in the downmix, that is mathematically 100% compatible to the original stereo signal. ISOSTEM Upmix can store parameters for various operating conditions in presets (e.g. upmix to 3.0, to 5.1 or level in LFE channel). It is not necessary to create genre-dependent presets, since the ISOSTEM Upmix algorithm distributes the components of the stereo signal to 5.1 solely by means of physical properties. ISOSTEM Upmix is used mainly in broadcast, recording studios and post-production.

ISOSTEM Loudness Ranger

The ISOSTEM Loudness Ranger provides a dynamic control solution that achieves a reduction in the Loudness Range (LRA according to ITU BS.1770 and EBU R.128) without producing audible artefacts. The algorithm ISOSTEM Loudness Ranger combines multiple measurement layers from various time windows, and applies numerous infinitesimal signal corrections. In this way the LRA can be reduced without affecting the quality of the signal. Furthermore the method either adjusts the programme loudness of the signal to a user-defined value or alternatively preserves the original value. In any case an adjustable maximum True Peak Level is met.

Read more


4. ICSA 2017 in Graz

The 4th International Conference on Spatial Audio (ICSA) is happily awaiting you in Graz, Austria. The Institute of Electronic Music and Acoustics (IEM) and the University of Music and Performing Arts in Graz are the 4th ICSA's hosts. This extraordinary venue...

Read more


ISOSTEM is available at DSPECIALISTS or our international distributors. If you are interested in distributing ISOSTEM or if there is no distributor in your country, please contact us.

More information