Berliner Lautsprecher Orchester (since 2013) developed by Wolfgang Heiniger. This orchestra has not a symmetrical set-up, in contrary to the Acousmonium.
A short video showing some of the loudspeakers used in the nowadays Acousmonium of the GRM:
Bird and Person Dyning (1975) by Alvin Lucier
Philips Pavilion (1958) by Le Corbusier, Iannis Xenakis and Edgar Varèse: