INA 155
UX Quotes
Since Pierre SCHAEFFER created the Musical Research Group in 1958 – which became a part of the National Audiovisual Institute (INA) in 1975 – speakers play a primordial role in our musical research and creative activities. Since 1974, our ‘loudspeaker orchestra’ (a.k.a. ‘acousmonium’) ‘plays’ music at the GRM concerts. Each composer chooses the loudspeakers, according to their sound color and their personality. On the other side, our monitoring speakers are references, the equivalent of a tuning fork. They must therefore be of an immaculate fidelity during the production, recording, mixing or mastering stages of our projects. We have been looking for a genuine reference monitoring system since 2008. We finally decided to launch a call for applications in 2013. Each GRM member, composer, musician or sound engineer were able to listen to, and compare, a very large choice of products, either dedicated to studio monitoring or to mastering-oriented HI-FI, made by Danish, Finnish, Japanese, British and French manufacturers. 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 coloration, embellishment or bias. 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.

Philippe DAO
Musical production manager, composer, sound engineer (INA GRM)

This 3-way system hosts a Dynaudio Esotar 1-inch dome tweeter for high frequencies, and an ATC 3-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. Each one of these transducers is an undisputed reference component in its class. All three have been carefully selected, evaluated, listened to and combined. 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 optimized to reduce diffraction effects, while minimizing waves in the frequency range to be reproduced. Its totem-shape, its height and its precise ‘angulation’ create a large and comfortable sweet-spot for a sitting or standing listener, keeping a perfect alignment for the impulse response. Each system is tri-amplified, using a proprietary oversized amp section for a total power of 3 x 1000 Watts with an 8-ohm impedance. Every channel is equipped with a very powerful DSP engine, powering very low-latency IIR and FIR filters ensuring an excellent amplitude/frequency response and outstanding phase response. The technology combines solid-state and passive components, selected after intensive listening sessions, 6-layer PCBs, etc. to get the lowest distortion and noise levels.

Michel DELUC
Research and Development Director (Amadeus)