This was in my opinion the biggest surprise of SIHH 2015. In their Royal Oak Concept RD#1, Audemars Piguet haven’t invented a new category of watch, and they themselves have been making minute repeaters for over a century. But for the first time, they have succeeded in making a minute repeater that you can hear. Amazingly, its sound is enhanced by wearing the watch on the wrist. In addition, this watch is also a tourbillon, and a chronograph. For a grand complication, it has a very modern, almost minimalist appearance.
You just have to take a look at some youtube videos to discover that watchmakers often seem embarassed by the tiny sounds of their minute repeater. Patek Philippe’s are louder, but they sacrifice the waterproofness and dustproofness of their watches to enable the sound to get out. A sealed, waterproof case muffles sound. The latest A. Lange & Söhne Zeitwerk Minute Repeater is beautiful but virtually inaudible beyond a couple of metres. The Royal Oak Concept RD#1 is different. You can hear it in a crowded room, and its water resistance is at 2 atmospheres, meaning 20 metres depth of water.
It’s a concept watch, not on sale. It took eight years to develop, and much of this time was dedicated to research on the principles of stringed instruments, working with the EPFL (Ecole Polytechnique Federale de Lausanne), a craftsman who makes violins and other stringed instruments, a consultant from the Geneva Conservatoire, and a sound engineer. There is now an Acoustics Lab at the Audemars Piguet manufacture in Le Brassus.
Audemars Piguet are not saying much about how they achieved it, partly because there are three patents still in the pipeline. But their designers were particularly intrigued by the sound of a 1924 minute repeater, with steel gongs producing a harmonious sound, attained by careful filing, and so something of that distant technology has been incorporated into the new piece. The gong has been shaped so that the principal note is accompanied by another “partial”, similar to a harmonic, approaching the ideal of a major third. They also worked on the striking mechanism, reducing the whirrs and clunks that would otherwise disturb the sound. The extensive use of titanium will also be involved: light metals transmit sound better than heavier metals such as gold or platinum.
The watch has a hand-wound movement, Calibre 287455, with 470 components. It has a titanium case and caseback, screw-locked crown and pushpieces, titanium pushpiece guards, an openworked black dial, and a black rubber strap. Reference 26576TI.OO.D002CA.01. Read more here.