Operation Manual

EF1210 U
SER
M
ANUAL
A-8 http://www.aspi.com Copyright © 1999, All Rights Reserved
• The default choice is pink noise played in both Zone A and Zone B.
• Choose “No noise generated” for no pink noise in Zone A and Zone B.
• Choose “Pink noise to Zone A” for pink noise in Zone A.
• Choose “Pink noise to Zone B” for pink noise in Zone B.
ii. Select input channel to calibrate.
iii. You will need a Sound Level Meter (SPL Meter) for this step. Adjust micro-
phone and loudspeaker to attain the appropriate dB SPL at the microphone using
the following steps:
• Set the SPL meter to C weighted, slow response. Choose the appropriate dB
SPL range using Table 7 below based on microphone type and the talker’s
distance from the microphone.
• Place the SPL meter beside the microphone. Point the SPL meter and the
microphone toward the loudspeaker.
• Adjust the microphone/loudspeaker so that a nominal dB SPL level based on
Table 7 is registered at the microphone.
iv. Adjust level until the first yellow LED (0 dB) on the I
NPUT
S
IGNAL
L
EVEL
M
ETER
of the EF1210 front panel is lit.
v. Repeat for each input channel or click the Apply Gain to All button to
apply the Input Gain to all input channels. Return all microphones to their nor-
mal operating location and orientation.
vi. After all input channels have been calibrated, press the Next button at the bot-
Table 7: Typical distance from microphone to talker and appropriate dB SPL level.
M
ICROPHONE
T
YPE
T
YPICAL
D
ISTANCE FROM
T
ALKER
(
FT
.)
SPL L
EVEL
(dB)
Lavalier 6 inches to 1 foot 89 dB SPL
Gooseneck 1-2 feet 77 dB SPL
Boundary or other tabletop 2-3 feet 73 dB SPL
Ceiling 4 or more feet 69 dB SPL
Note.
Always double check the microphone level with normal speech
once the microphones are in normal operating position. Actual
speech levels may vary depending on room reverberation, etc.
Verify that you set a reasonable level (three green LEDs and one
solid yellow LED, or 0 dB) by actually talking and looking at the
meter.
Note.
It is vital to move the SPL meter and/or microphones so that each
microphone sees the correct dB SPL acoustic level as you are cal-
ibrating. Do not assume that because the first microphone sees
the dB SPL level, all other microphones will see the same level
(unless they are moved to occupy the same location as the first).
Note.
Use caution if the microphones lie in two acoustically separated
zones and you are only calibrating one zone. As you cycle through
microphones that lie in the other zone, no activity will be indicated
on the I
NPUT
S
IGNAL
L
EVEL
M
ETER
on the EF1210 front panel.