VOICECRAFTER
TM
CONNECTING EXTERNAL EQUIPMENT
18
7.4.1 INSTALLATION
Connect a ‘mix-minus’ output of the
mixer (containing only near end signals)
to the Mic 2 input of the Voicecrafter.
Connect Line Out of the Voicecrafter to
an auxiliary or un-used input of the
mixer. Connect a ‘composite’ output of
the mixer (containing both near end and
far end signals) to the input of the
amplifier. Configure Mic 2 for line level
input by Clicking on Input Mode under
Mic 2 (ACOUSTIC screen). Use F3
⇒
to
select Line Input (Balanced or Un-
balanced depending on the mixer used).
7.4.2 CALIBRATION
Both the external mixer and amplifier
need to be calibrated for nominal levels
expected by the Voicecrafter. The
external mixer needs to be calibrated for
nominal level expected at Mic 2 input
(VC3000 & VC3010 = -35dBm;
VC3001 & VC3011 = 0dBm).
Use the following procedure to calibrate
the external mixer and amplifier:
1. Use a white/pink noise source to
direct noise at one of the
microphones. The Voicecrafter
white noise generator may be used
for this calibration. To do so, first
Click on AutoAdapt (ACOUSTIC
screen) and use F3
⇒
to select
FULLY DISABLED. Then, enable
the internal white noise generator by
clicking on the Noise button
(ACOUSTIC screen). Use F3
⇒
to
set white noise to ENA (enable).
2. Use a sound pressure level meter to
measure the noise level at one of the
microphone locations.
3. Adjust the level of the noise source
so that the sound pressure level at
the microphone is 72dB. If the
Voicecrafter is being used as the
white noise source click on the
Speaker Gain button and use F2
⇐
and F3
⇒
to adjust gain levels.
4. Measure the DSP Gain EC_Si. To
do so, click on the DSP AVE button
(ACOUSTIC screen). Use F2
⇐
or
F3
⇒
to display EC_Si. EC_Si is a
momentary reading, and is only
updated by clicking DSP AVE again.
5. Adjust the external mixer output for
nominal level (see paragraph 7.4.2),
and then adjust Mic 2 Gain
(ACOUSTIC screen) so that the
average EC_Si is approximately
-20dB. Repeat steps 1~4 for all mics
in the installation. Once Mic 2 Gain
is established, level adjustments
should be made only at the
individual inputs of the mixer.
6. After all of the mics are calibrated,
turn the white noise source off. If the
Voicecrafter is being used as the
white noise source, click on Noise
and use F3
⇒
to set white noise to
DIS (disable).
