GSM/GPRS Modules
GSM Module Audio Design Guide
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2.7. Component of SPK
A SPK and receiver with higher sensitivity, flatter frequency response, less THD and impedance of
32Ω(receiver), 16Ω(receiver) or 8Ω(speaker) is recommended. These technical data are often shown in
data sheet of SPK and receiver. For SPK, its frequency response and THD performance can be tested by
speaker test system. SPK frequency and THD response are shown in Figure 22 and Figure 23.
Figure 22
：
SPK Frequency Response
Horizontal axis is frequency, longitudinal axis is loudness and unit is dB.
Note
Quectel
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