Greubel Forsey’s first ever grande sonnerie watch, which took more than a decade to make, has a price tag of more than a million dollars and a sound like no other, according to the luxury Swiss brand.

The Greubel Forsey Grande Sonnerie has no fewer than 935 parts, two patents and an acoustic cage made from titanium that is said to produce an extremely pure sound.

A grande sonnerie is the most challenging of watch complications as it can chime in three different modes. In grande sonnerie mode the movement will chime every quarter and hour, in petite sonnerie it will strike the hours and as a minute repeater it will chime the hours, quarters and nearest minute on demand. 

At the very start of their partnership, Robert Greubel and Stephen Forsey set out to develop their own contemporary take of this regal complication. 

For eleven years, both men worked in secrecy to assemble the 935 parts of this timepiece, striving to achieve absolute harmony between the movement, the exterior and acoustics.

The new timepiece represents the quintessence of their expertise and ideal of watchmaking excellence.

The Greubel Forsey Grande Sonnerie has powerful acoustics, is water resistant to 3 atm and ergonomically designed for ease of use. The timepiece is equipped with a silent striking regulator and a 24-second tourbillon, all housed within a standard Greubel Forsey case.

The most important elements and indications – such as the tourbillon, the cathedral gongs, the striking hammers, and the power reserve and mode indicators – were incorporated with the greatest care to ensure architectural balance. 

This was no mean feat – the watch designers succeeded in housing the 935 parts comprising this timepiece and its exterior in a space measuring 43.5 mm in diameter and 16.13 mm high. 

The movement is manually wound, but the striking mechanism features a self-winding system which provides about 20 hours of power reserve in grande sonnerie mode. The minute repeater and its additional striking mechanism sounds the exact time on demand, down to the minute. The specific characteristics of this timepiece include 21,600 vibrations/hour and a 72-hour chronometric power reserve. 

The watch has three modes to choose from: grande sonnerie (which strikes the hours and the quarters in passing), petite sonnerie (which strikes the full hours in passing) and silent. The pure and rich sound of the grande sonnerie is enhanced by an acoustic resonance cage made from titanium. 

The Grande Sonnerie is Greubel Forsey’s most complex creation to date and with this timepiece, it joins a very exclusive circle of watchmakers offering a grande sonnerie. 

Greubel Forsey will bring out between five and eight of these watches every year, at a price of CHF 1.15 million ($1.13 million).