Diffusion
Following the tradition of Pierre Schaeffer, Diffusion refers to the live spatialization of tape music, respectively fixed media content. Typically, the music is played back in a low channel order (e.g. Stereo) and sent to a large number of loudspeakers using an 'inverted' mixing desk.

Natasha Barrett diffusing on a 3D system at a TU Studio concert (Villa Elisabeth, 2018).
The Acousmonium
The GRM (Groupe de Recherche Musicale) Acousmonium is an elaborate loudspeaker setup, designed for the diffusion of acousmatic music. It is made for touring and was first presented in Germany at the 1983 “Inventionen” festival by François Bayle. The system returned to Berlin for the 2008 edition of the SMC, where it was paired with the large WFS system at TU Berlin's H104:
The Acousmonium at TU Berlin (H104) during SMC 2008.
The BEAST
The Birmingham Electroacoustic Sound Theater (BEAST) is a modern version of the Acousmonium approach. It features 100+ loudspeakers in multiple groups with specific characteristics and purposes:
Different loudspeakers of the BEAST system.

BEAST setup at CBSO Centre, Birmingham, May 2009 (Wilson, 2010).
The BEAST was presented in Berlin at the 2010 Inventionen Festival, when Jonty Harrisson was guest professor at TU Berlin. Read more in the online archive of the festival.

BEAST at Inventionen Festival 2008 (Elisabethkirche, Berlin).
References
2010
- Scott Wilson and Jonty Harrison.
Rethinking the BEAST: recent developments in multichannel composition at birmingham electroacoustic sound theatre.
Organised Sound, 15(3):239–250, 2010.
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