Nexo speakers installed in project 400-metres underground in 80% humidity

Nexo speakers installed in project 400-metres underground in 80% humidity
French AV integrators Atelier du Son et de l’Image (ADSI) have installed a Nexo sound system at the Musée Grévin wax museum in Paris.

Back in 2024, ADSI Chargé d’affaire Bertrand Gazi called in Nexo’s Engineering Support team to demo a proposed new sound system to operators of the Grotte St Marcel and their scenography partners Creafactory. With 60 km of galleries, the Grotte St Marcel is one of the biggest caves in France where visitors discover huge halls following a former underground river in a 400-metre long circuit, with the experience heightened by sound and light shows.

ADSI completed the installation a year later of a system comprising 6 each of Nexo’s EN54-rated ePS12 and ePS10 speakers with 3 x eLS18 subs, and a total of 18 of Nexo’s ID14s. All cabinets are finished in custom RAL colours to blend into their surroundings and permanent fixture to the cave walls using mounting brackets was strictly prohibited, so speakers are freestanding amongst the rocks, many dripping with water.

Nexo quality director Cyril Picard highlights the difficulties of working in this environment; "“During development the ePS-EN54 speakers were subjected to 800 hours of salt spray and 600 hours UV testing, although UV was clearly not going to be an issue 400-metres underground. From the use of high-grade A4 stainless-steel screws to UV-protected cloth and polyurethane coatings, every detail has been considered. Even so, this was a unique opportunity to inspect the system after almost a year of continuous use in more than 80% humidity. All of the cabinets were completely soaked but still functioning perfectly.”