Custom Amadeus monitors for France’s National Audiovisual Institute

Amadeus was chosen to design a custom set of reference monitoring speakers for the National Audiovisual Institute’s (INA) Studio 116 in Paris.

Dedicated to the Groupe de Recherches Musicales (INA GRM), which sponsors major concerts and supports research into electro-acoustic music and recorded sound, Studio 116 is one of the largest of 61 recording studios at Maison de Radio France, located beside the River Seine.

When on the lookout for a first set of reference monitors for its GRM, INA requested design ideas from many of the world’s leading speaker manufacturers, before eventually opting for an Amadeus solution. The new Amadeus monitors have only just been installed in Studio 116 and are already being used for INA projects.

"We have been looking for a genuine reference monitoring system since 2008. We finally decided to launch a call for applications in 2013. A first draft of a soffit-mounted system, custom-designed by Amadeus, quickly caught our attention – every nuance, dynamic, even the tiniest details of a piece were reproduced without any colouration, embellishment or bias," said Philippe Dao, musical production manager, composer and sound engineer at INA GRM. "As the initial form factor did not match our constraints, we asked Amadeus to design a column-shaped version, keeping the neutrality, the timbral precision, the dynamics and the liveliness, which had seduced us in the first place."

Amadeus co-founder Bernard Byk added: "Our first collaboration with the GRM dates back to 2011, when we designed a multi-diffusion loudspeaker ring for their concerts, made with coaxial Amadeus PMX 5 speakers and custom bass speakers. We feel very proud and honoured about this new collaboration. Such projects continue the works we carry out with research institutes such as the IRCAM, The Royal Conservatory of The Hague or the French National Centre for Scientific Research (CNRS), for example, and allow us to push the sound limits even further, by always developing more innovative systems."

Michel Deluc, director of research and technical development at Amadeus, outlines the physical properties of the new system: "The monitor designed and manufactured for the Groupe de Recherches Musicales, naturally named INA 155, was derived from the Model 155, a soffit-mounted monitor designed by Amadeus. This system was modified and optimised to be used in a freestanding mode, combining the ‘Mastering Monitor’ philosophy with a ‘Mains Monitor’ sturdiness. This three-way system hosts a Dynaudio Esotar one-inch dome tweeter for high frequencies, and an ATC three-inch driver for the mid frequencies.

"Low end is reproduced by a direct-radiating 15-inch woofer, designed by TAD, mounted in a bass reflex box. Its cone-shaped diaphragm is able to withstand very high excursion levels, without any deformation. The very high volume box is manufactured with multi-layer panels, combining, among other materials, multi-wood walls, high-density modified bitumen ‘elastomers’ (polymers) and mineral fillers. This gives an optimal rigidity/damping ratio, allowing an extended frequency range of 25 Hz to 40 kHz. Several internal resonators and stiffening pieces work together in a complementary way to dissipate the vibrating energy, according to a perfectly controlled harmonic gradation. The baffle shape has been optimised to reduce diffraction effects, while minimising waves in the frequency range to be reproduced."

Amadeus has already begun work on an upgraded version of the INA 155s monitors, according to Byk: "Moved by a desire to push to the ultimate level in both the precision and transparency of this monitor, we thought about designing, in collaboration with the National Audiovisual Institute, an extension hosting a wide-band ribbon transducer with a double air gap. This would allow the sound to radiate the high-frequency sounds within an acoustic line, with a wide horizontal dispersion angle (almost 180°) and a very narrow vertical dispersion angle (less than 10°). Designed to be a very precise ‘sweet spot’ source only, this complementary transducer would make it easier to suppress the dominant vertical sound reflections, increase the harmonics definition, and would allow richness and extreme precision for the highest audio frequencies."

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