The simplicity of fabrication of th

The simplicity of fabrication of the cymbal transducer allows
for tailoring of different resonant frequencies in a single device
by introducing small differences between the end-caps [4]. However,
this sensitivity to changes in geometric dimensions of the
end-caps was found to be a significant drawback in many applications
where high efficiency was required. Irregularities introduced
in the fabrication of cymbal transducers, such as asymmetries in
the epoxy layer and end-cap dimensions, create a double resonance,
characterised by a double-peak in the measured frequency
response [4,10,11], and this effect appears in approximately 80%
of assembled transducers. Several studies have focused on improving
symmetry. A screen-printing method was proposed to improve
the deposition of the epoxy layer [10], but this only improved the
percentage of single-peak devices to approximately 35%. An alternative
approach [11] involved tuning one of the end-caps to the
same resonance frequency as the other by adding a small mass to
the top of the end-cap.