Assertion: speaker | /r/CapableOf | use piezoelectric transducers
Facets:
value: of the traditional magnetic coil setup
type: OTHER
value: based on vibrating crystals
type: OTHER
value: sometimes
type: TEMPORAL
Source sentences:
text: Speakers that need to produce high-frequency sounds (or ultrasound, well beyond the range of human hearing) sometimes use piezoelectric transducers, based on vibrating crystals, instead of the traditional magnetic coil setup.