The minute repeater is a wonderful anachronism. Originally designed to be able to chime the time in the dark before the advent of electric lighting, it is today one of the most sought-after and most hard to produce complications in watchmaking. But whereas the watchmakers who worked on the first (pocket) minute repeaters were often musicians and had a good ear for sound, today they don’t. Instead, brands like Audemars Piguet turn to specialist researchers at research institutions such as the EPFL in Lausanne in their quest to produce the ultimate minute repeater.
But just what is the ultimate minute repeater and just how do you determine what is the “purest” sound? Ultimately, it is not just the individual ear of the collector but also his or her brain that will make the difference, since our brains automatically tune out certain frequencies (think about having a conversation over background noise, for example). So watch brands are therefore faced with the choice between an optimal sound or optimal projection. Audemars Piguet has chosen the latter, but even then, acoustic theory will only get you so far.
Audemars Piguet seems to have hit the right note with the Royal Oak Concept “Supersonnerie” presented at the SIHH earlier this year. Its chiming mechanism has a frequency that matches that of a baby crying (4000 Hz to be precise), and new parents know only too well how effective this frequency can be. Much more important, however, is the innovative construction of the chiming mechanism in this watch, since the gongs that produce the sound have been separated from the mainplate and are housed on their own resonating board, forming a kind of mini echo chamber inside the watch. This avoids the counter-intuitive design of most other minute repeaters, which almost eliminate resonance from the outset by connecting the gongs to the movement, producing an acoustic design that is akin to playing a guitar while sitting on its strings.
The improved sound projection achieved by the Supersonnerie is the key to its success (which is why Audemars Piguet avoids communicating statistics in decibels, which is a measure of volume only). The difference is striking, since the chimes are clearly audible on the wrist, at a distance of a few metres, or even from another room, as Sebastien Vivas, Director of the Audemars Piguet Museum, took great delight in demonstrating to WorldTempus when we visited the brand’s workshops (see our video).
The new system offers other benefits, too: since the resonating membrane inside the case is independent of it, the material used for the case has no effect on the sound of the minute repeater. This means that Audemars Piguet is not restricted to the precious metals usually employed for the cases of minute repeaters and can offer the Royal Oak Concept Supersonnerie in a titanium case… for just over half a million Swiss francs.
