At last year’s SIHH, Audemars Piguet introduced a concept minute repeater – the RD#1 “Acoustic Research” – as part of a series showcasing new technology and materials developed by the brand’s R&D department. The prototype was the result of eight years of research and represented a breakthrough in the acoustic quality and volume of chiming technology. This year the concept has become a reality. The Royal Oak Concept Supersonnerie is now performance-ready and commercially available.
While some minute repeaters need to be held to the ear in order to listen to the melody, the Supersonnerie chime can be heard loud and clear from the bleachers. Audemars Piguet is not exaggerating when it says the chime is 10 times louder than a typical chiming watch. The main innovation lies in the case construction. The chiming mechanism applies the principles of stringed instruments. Gongs are attached to a purpose-built copper-alloy plate that Audemars calls a “sound board” positioned between the movement and the mainplate. Normally the gongs are attached to the plate itself. The principle is akin to the way strings work in an acoustic guitar, stretched over a hollow case that amplifies the sound. Gongs are conventionally attached to the mainplate, which can dampen rather than enhance the chime. The Audemars Piguet system essentially separates the acoustical from the technical, resulting in a cleaner, louder sound, amplified by the space between the plate and the sound board. This is further enhanced by a silent striking regulator built into the movement that blocks any interference noise from the governor, the mechanism that triggers the strike.
Another innovation is the shape of the hammers, which are flexible, so they work like a shock absorber to eliminate secondary noise. The new mechanism also picks up the tempo, eliminating the sound gap between the hours and minutes when there are no quarter hours to strike. The time in between is reduced by 50 percent compared to a conventional repeater, which pauses between hours and minutes when there is no quarter strike.
The case is titanium, and the openworked dial and blackened bridges give the watch a contemporary look compared to the conventional designs of most repeaters. To develop the technology in the Supersonnerie, Audemars Piguet partnered with the Ecole Polytechnique Federale de Lausanne (EPFL), a Swiss organization dedicated to the study of acoustics.