20
Testing FM Systems with FONIX 6500-CX Analyzers
1.3.6 Test environmental microphone response with typical input—EEF65
1. Set up the environmental microphone for testing as described in Section 1.1.4. Set
the FM receiver to receive FM+ENV signals.
2. Use
[
∨
] to set the source level to 65 dB SPL and wait for the response to stabilize.
3. This measurement will be referred to as EEF65, or the Electroacoustic FM and
Environmental Response with 65 dB SPL input to the environmental microphone.
4. Compare EEF65 to EHA65 (from Section 1.3.4) and EFE80 (from Section 1.3.5). If you
have Multi-Curve, do the following:
a. Press
[MULTI].
b. Highlight
MULTIPLE
CURVES.
c. Press
[START].
d. CRV 1 will be selected for the first Multi-Curve slot. This is the EEF65 response.
CRV 2 should be selected for the second Multi-Curve slot. This is the EFE80
response. Use [
∨
] to select the third Multi-Curve slot.
e. Use [<, >] to select CRV 3 for the third Multi-Curve slot. This is the EHA65
response.
f. Compare EEF65 (CRV 1), EFE80 (CRV 2), and EHA65 (CRV 3). For a successful
fit, the EHA65 and EEF65 should be similar, and the EFE80 should be 7-10 dB
higher. See Figure 1.3.6.
Figure 1.3.6
Comparison of EHA65 (CRV1), EFM80 (CRV2), and EEF65, the
environmental microphone response at 65 dB SPL