Beyond the cathedral gong. The physics of perfect sound. Fifteen platinum minute repeaters, four patents, and a chime heard six times further away. The 5750P uses two classic gongs, not cathedral gongs. Its case is inspired by the cathedral-gong Ref. 5178 and shares its 40 mm diameter. Its patented, all-mechanical fortissimo "ff" module, a flexibly suspended steel sound lever driving a 0.2 mm sapphire wafer, amplifies the chime. Patek Philippe states that a classic minute repeater heard at 10 m sounds as loud and clear as the 5750P heard at 60 m. Fifteen pieces in 950 platinum, the case metal that is hardest on sound, chosen to prove the system. Four patents cover the sapphire loudspeaker, the sound-amplification mechanism, the platinum hammers and the coplanar gong attachment.