Resonance.

Few know what it is. Even fewer have ever made a resonant watch.

However, even if you are not acquainted with the subject of resonance, the stunning visuals of Armin Strom’s latest wristwatch will certainly have you sitting up and taking notice.

But before we jump in, here’s an abbreviated history of resonance in watchmaking.

Resonance is a physical phenomenon in which the vibrations of a primary body excite equal and sympathetic vibrations in a secondary body.

Synchronized motion in mechanics has fascinated watchmakers since the time of Christiaan Huygens (1629-1695), who first invented the pendulum (and then the balance spring) before experimenting with two pendulums.

Antide Janvier (1751-1855) and Abraham-Louis Breguet (1747-1823) also experimented with resonance, both having made double regulators with pendulums coupled by resonance.

Breguet thought that if you go from the idea that a body in motion can only lose motive energy by giving it to other bodies, and then that body in turn gives its energy to others, and so on in perpetuity, that the motive energy in the end is not lost, but shared.

Breguet’s two pendulums swung at the same frequency, but in opposition; an outside shock that slowed one down increased the speed of the other one by the same amount. And the most amazing part was that thanks to resonance, both pendulums strived to synchronize, thereby minimizing the effects of the outside influence on the timing.

Inspired by Janvier, one of his favorite antique watchmakers, François-Paul Journe was the first to place resonance in a wristwatch. His Caliber 1499, containing patent EP 1 760 544 A1, made its debut in the Chronomètre à Resonance in 2000.

Armin Strom Mirrored Force Resonance Fire

To provide an idea of how difficult the successful horological execution of this concept is, here is the exhaustive list of the few clockmakers and watchmakers in the entire history of horology that until today have successfully designed and constructed resonant timekeepers: Antide Janvier (1751-1855), Abraham-Louis Breguet (1747-1823), Davide Walter, Stephan Gagneux/Beat Haldimann, Florian Frisch/Claude Schauerte, and François-Paul Journe. Today one more gets added to that illustrious list . . .

And now: Armin Strom

And now Armin Strom is added to the very short list of illustrious watchmakers that have successfully incorporated resonance into a timepiece: the Mirrored Force Resonance.

Armin Strom Mirrored Force Resonance Fire

“Nothing is ever 100 percent new in watchmaking,” technical director Claude Greisler explained to me with regard to the truly unprecedented type of watch to emerge from the well-outfitted factory of Armin Strom.

Greisler and his team weren’t exactly setting out to look for a crazy complication, but they were looking for something interesting that made sense to improve chronometry. The idea was more to create a watch with an interesting display whose mechanics made sense in terms of adding to the improvement of timekeeping.

“And capturing something that could also serve as an interesting animation was also a priority,” he added.

And this the team has done incredibly successfully, though it took the better part of two and a half years: the dual resonant regulators are eminently visible on the dial as they perform their “revolutionary” work, turning in opposition to each other but always striving for synchronicity thanks to resonance.

Armin Strom Mirrored Force Resonance Fire

And the 3.5 Hertz (25,200 vph) frequency is also perfect: it is slow enough to allow the observer to really appreciate the resonant regulators in action as they perform their magic on the watch’s dial side, but fast enough to guarantee maximum precision. All in all an unusual but good choice at which to set the balance frequency.

Another great element surrounding resonant regulators is their reaction to shocks. If the watch should experience some sort of perturbation that disturbs the frequency of one or both balances, resonance will ensure that they strive to get back to beating in harmony at the correct rate.

While other modern timepieces incorporating resonance have two sets of mainsprings, gear trains, escapements, and balances, with a rack and pinion keeping the distance between the two balances adjusted, the Armin Strom oscillators each comprise twin balance wheels and balance springs only connected using a resonance clutch spring invented by the Armin Strom team. It is the balance spring studs that receive the resonant impulses.

Armin Strom Mirrored Force Resonance Fire

And if you’re thinking that this dial-side display is unlike anything you’ve every seen before, you’d be 100 percent correct: this display of oscillators and spring is unique. And the almost butterfly-shaped resonance clutch spring was calculated, simulated, prototyped, and shaped to scientific perfection within the four walls of Armin Strom’s Biel-based manufacture.

“And everything you see here has been classically manufactured,” Greisler explained. “We haven’t used silicon or any new technologies in this watch.”

Armin Strom Mirrored Force Resonance Fire

It goes without saying that the shape of the steel spring is the important element in ensuring that this timepiece performs its mathematical magic flawlessly.

The two connected oscillators revolve in opposite directions, one rotating clockwise and the other counterclockwise: this looks much like a magic trick, though in reality it’s just physics.

Armin Strom Mirrored Force Resonance Fire on the wrist

And once the 48-hour power reserve of the watch has been exhausted and the movement needs winding, the twin balance wheels only need about 10 minutes to once again synchronize. In case of shock, it takes only a few minutes for the two balances to find their resonant rhythm once again.

Exciting, animate bodies

An animate body always transmits vibrations to its environment. As another body picks up the vibrations created by the first, it absorbs the energy and begins to vibrate at the same frequency. In physics parlance, the first is called the “exciter” and the second the “resonator.” Resonance, therefore, sees two bodies harmonize at one frequency.

Precisely regulating the two bodies allows a position to be found where the balances continually correct each other to maintain maximum precision: this is the big advantage of resonance.

Armin Strom Mirrored Force Resonance Fire

The advantages to creating resonance in a wristwatch are in fact myriad. For one, resonance exercises a stabilizing effect on the watch’s ability to keep accurate time. For another, it helps conserve energy in the movement thanks to the exciter/resonator relationship. And, finally, it helps reduce negative effects on the watch’s timekeeping accuracy in the case of shock.

View through the display back of the Armin Strom Mirrored Force Resonance Fire

“This was an incredible new frontier for us,” the humble Greisler explained. “Making perpetual calendars or tourbillons is far, far easier than spending years calculating springs. This is uncharted territory that we have entered.”

Armin Strom Mirrored Force Resonance Fire

For more information, please visit www.arminstrom.com/en/collection/mirrored-force-resonance-fire.

Quick Facts
Case: 43.4 x 13 mm, pink gold
Movement: manually winding Caliber ARF15 with visible resonance clutch spring, two independent, symmetrically mirrored regulators beating at 25,200 vph / 3.5 Hz frequency
Functions: hours, minutes, twin display of luminous seconds
Limitation: 50 pieces
Price: 67,000 Swiss francs
Remark: delivered with additional rubber strap