Music by numbers

CD players and some modern amplifiers work with high-quality digital sound,
but loudspeakers are still analogue, using a continuously varying voltage rather
than digital pulses to generate sound. In EP 810 810, Sony describes a
loudspeaker that is driven be a digital signal. Like most speakers, it has a
coil which moves to and fro in a magnetic field to pump a piston, creating sound
waves. But the coil is divided into 16 sub-coils, each fed by one of the 16 bits
of coded information. Normally, this would require 32 wires, but Sony gets rid
of the spaghetti by using a multi-coiled transformer to transmit to the
coil.