A parametric loudspeaker system is described which is based upon the
FM-modulation of an ultrasound carrier. Known systems work with
AM-modulation. The FM-modulation produces a good matching to the resonant
transducer such as the conventionally employed piezo-ceramic transducers.
The resonance slope of the transducers is used for FM/AM-conversion. This
FM-resonance principle can advantageously be employed in a multi-path
loudspeaker system, in which the transducer works in the optimal
resonance range in each of the paths. With the conventional AM-modulation
this is not possible. The FM-resonance principle can also be used in
resonance-free or resonance-poor transducers, such as for example
electrostatic transducers.