Murata's latest piezoelectric ceramic speaker measures just 1.2mm in thickness.

Side ventilation in the metal housing helps to keep the thickness down.

Two features of piezoelectric ceramic speaker actuators are that they have no magnetic parts such as magnets or coils, and being primarily a capacitive load, they can reduce power consumption in the voice band.

Frequency response of the rectangular speakers is an improvement over circular diaphragms as they are multi-modal - multiple oscillation modes can be generated along the long and short sides of the diaphragm, to create as many 'peaks' on the frequency axis as possible.

Another improved feature of the VSLBP1913E series is  the soft and flexible resin film the diaphragm is mounted on. This film reduces the primary resonant frequency and damps resonant characteristics of the piezo ceramic, contributing to flattening the frequency characteristic.

The diaphragm's multi-layered piezo ceramic construction creates powerful sound, up to a sound pressure level (SPL) of 90dB maximum (measured at 1kHz, 5.0Vrms, sine wave, at 0.1m, 0dB:20µPa).