User's Manual

GE866-DUAL Hardware User Guide
1VV0301051 Rev. 2 – 2014-04-07 7
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Reserved. Page 58 of 82
Mod. 0805 2011-07 Rev.2
11.7.2. Frequency Behaviour
The frequency behavior represents the effectiveness of the
reproduction of the applied signals. Because performance is
related to a square driving waveform (whose amplitude varies
from 0V to Vpp), if you modify the waveform (e.g. from square
to sinus) the frequency response will change.
11.7.3. Power Supply Influence
Applying a signal whose amplitude is different from that
suggested by the manufacturer, the performance change
following the rule “if resonance frequency fo increases,
amplitude decreases”.
Because resonance frequency depends on acoustic design, by
lowering the amplitude of the driving signal the response
bandwidth tends to become narrow, and vice versa.
Summarizing: V
pp
↑  f
o
↓ V
pp
↓ f
o
↑
The risk is that the fo could easily fall outside of new
bandwidth; consequently the SPL could be much lower than the
expected.
WARNING:
It is very important to respect the sense of the applied
voltage: never apply to the "-" pin a voltage more positive
than the "+" pin: if this happens, the diaphragm vibrates in
the opposite direction with a high probability to be expelled
from its physical position. This damages the device
permanently.
11.7.4. Working Current Influence
In the component data sheet you will find the value of MAX
CURRENT: this represents the maximum average current that can
flow at nominal voltage without current limitation. In other
words it is not the peak current, which could be twice or
three times higher. If driving circuitry does not support
these peak values, the SPL will never reach the declared level
or the oscillations will stop.