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 ISOSTEM products are developed in close cooperation with the French audio expert Antoine Hurtado and DSPECIALISTS as the executive development and sales company.

The ISOSTEM 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.


The Isostem procedure analyses the spatial energy distribution of an energy signal and differentiates between direct sound and ambient sound. Based on these results, the information is distributed from 2 channels to 5 channels, i.e. the frontal sound components are allocated to the front channels and the ambience components to the rear surround channels. This generates an upmix with all relevant spatial sources. As no new information is added, but the existing information is merely redistributed, the calculation is reversible. The ISOSTEM algorithm is the only upmix technology, that generates the original stereo signal in the downmix.



ISOSTEM Expert Frontansicht


ISOSTEM Expert Frontansicht oben

The EXPERT version contains the full range of functions and all setting options. Various parameters can be defined individually via a GUI and saved as presets. Up to 6 presets can be saved and retrieved as well as transferred to further ISOSTEM devices.


ISOSTEM Live Frontansicht


ISOSTEM Live Frontansicht von oben

The Live version is optimal for use in broadcasting. The setting options are limited in this version. In addition to pre-defined factory presets, presets imported out of the Expert version can also be used. LIVE also has an important backup function: If two devices are connected to one another and one of the devices has a malfunction, the system switches automatically to the remaining functioning device.

Plug-in für Minnetonka AudioTools Server

Plug-in für Minnetonka AudioTools Server

Plug-in for Minnetonka AudioTools Server

Plug-in für Minnetonka AudioTools Server

The ISOSTEM alogorithm has been licensed as plug-in for the AudioTools Server of Minnetonka. The range of functions of the plug-in will be equal to the hardware version 'Live', that works with predefined factory presets. These factory presets are delivered with the installation of the AudioTools Server, furthermore they can be downloaded from the ISOSTEM websote. Individual presets can be created with the hardware version 'Expert' and imported to the AudioTools Server.

ISOSTEM Plug-in für Audiokreuzschiene NEXUS

Plug-in for audio network system NEXUS

Plug-in for audio network system NEXUS

ISOSTEM Plug-in für Audiokreuzschiene NEXUS

The ISOSTEM algorithm has been licensed as a plug-in for the audio matrix NEXUS from Stagetec and fully integrated into the system. Up to two licenses can run on the XDSP06 card. The ISOSTEM function in the Nexus system will be equal to the ISOSTEM hardware version ‘Live’, which works with pre-defined factory presets. Individual presets can be created with the hardware version expert and imported to the ISOSTEM plug-in in the Nexus.

ISOSTEM Loudness Ranger

ISOSTEM Loudness Ranger ATS

ISOSTEM Loudness Ranger ATS

ISOSTEM Loudness Ranger ATS

The ISOSTEM Loudness Ranger is a processing module for dynamic control for AudioTools Server – a file-based audio automation platform for broadcasters. It 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.


ISOSTEM is a development of DSPECIALISTS digitale Audio- und Messsysteme GmbH and Antoine Hurtado. If you are interested in distributing ISOSTEM or if there is no distributor in your country, please address your inquiry to:

DSPECIALISTS Digitale Audio- und Messsysteme GmbH

Helmholtzstraße 2-9 L

10587 Berlin

Phone: +49 30 467 805-0
Fax:     +49 30 467 805-99

Our distributor in Brasil:

Av. Moaci, 395 – Cjto. 82
CEP: 04083-000
São Paulo – SP / Brazil

Phone: +55 11 3467-0132
Fax: +55 11 8180-1466

Our distributor in China:

China Representative Office
Room 901, Unit C, No.4 building,
Bai Zi Yuan, No.16, Bai Zi Wan Road,
Chao Yang District,
Beijing 100022
China P.C: 100124

Phone: +8610 87 73 21 98
Fax:     +8610 87 73 21 98 608

Our distributor in Denmark:

Interstage A/S
Phistersvej 31
2900 Hellerup

Phone: +45 3946 0000