BLUE SKY BMC MK III User Manual page 13

SETTING THE REFERENCE LEVEL
Step 1 TURN THE MASTER GAIN ON THE REMOTE TO -50dB AND
THEN TURN ON THE MONITORING SYSTEM
Step 2 Press the MENU button two times or until the display reads "CAL
CHANNELS". Now press the up arrow button and confirm that
the LEFT, CENTER, RIGHT, RIGHT SUR (right surround), LEFT SUR
(left surround) and SUBWOOFER GAIN are set to +0.0 dB, as
shown below. Use the "+" (R) and "-" (L) buttons to adjust levels
if necessary.
SUBWOOFER MAIN
GAIN = + 0.0 dB
Please note that the SUBWOOFER GAIN should not be confused
with the SUB OFFSET, which should be set to -10.0dB.
Step 3 Assign the 500-2.5kHz pink noise signal to the center channel
only. Confirm that all of your speakers are turned on and that
the gain on each speaker is set to a moderate level. Slowly
bring up the gain with the master gain control knob on the
BMC remote until you measure 85dB on the "C" scale, with the
response set to "Slow". SPL should be measured exactly at the
reference monitoring position, at ear level, with the SPL meter at
arms length, angled up at approximately 45 degrees and pointed
towards the source / up towards the ceiling. Note the gain
displayed on the remote when the center channel is at 85dBc. If
the display on the remote is at less than -20dB turn the gain on
the back of the center channel down and increase the level of the
BMC until a good compromise is reached (make a note of this
final setting). Typically using a reference gain setting of -10dB is
a good choice between overall electrical headroom, input signal
level, output signal level and giving the user an additional 10dB of
system gain above calibration level, when necessary.
Step 4 Once the "REFERENCE LEVEL" setting has been determined,
turn off the pink noise signal, make a note of the SYSTEM GAIN
reading on the remote. Set the gain controls on the rest of the
monitors to the same level as the center channel (subwoofer may
need more gain due to the offset setting).
Step 5 Saving the reference level: Press MENU 3 time, or until the display
reads "SETUP". Press the down arrow button (LFE) four times,
or until the display reads "SET REF GAIN", as shown below.
Turn the master gain control knob until the SYSTEM GAIN equals
the gain noted in step 4. Release the knob, being careful to
not nudge it and then press "+" (R) button, when the menu
reappears.
SET REF GAIN
SET GAIN-PRESS +
You have now successfully stored the preset "REF" level. Press
CANCEL to exit setup and then press the REF button to confirm
the setting is correct. The display will read "REF GAIN", with the
gain setting below (shown below). The REF LED will also be ON.
BMC MK III
USER MANUAL • 11 • 5.1 SYSTEM CALIBRATION (CONTINUED)
User Manual • 5.1 System Calibration (continued) • Page 13
REF GAIN
GAIN = -10.0 dB
SYSTEM ACOUSTIC LEVEL SETTING - INSTRUCTIONS FOR USING
BANDWIDTH LIMITED TEST FILES (using MOVIE / DVD RELEASE
level settings for this example)
Step 1 Exit REF mode, by pressing the REF button and then press
the MENU button two times, or until the display reads "CAL
CHANNELS".
Step 2 Turn the gain knob on the remote to the "REF" setting, as
determined in the previous section (-10.0 dB in our example).
Assign the 500-2.5kHz pink noise signal to the left channel. Push
the up arrow button (C) once, until the display reads "LEFT MAIN
GAIN". Adjust the gain using the "+" (R) and "-" (L) buttons, until
you measure 85dBc / SLOW at the mix position (adjustments are
made in .5dB increments). SPL should be measured exactly at the
reference monitoring position, at ear level, with the SPL meter at
arms length, angled up at approximately 45 degrees and pointed
towards the source / up towards the ceiling. Confirm that the
master gain setting has not been changed from the "reference
level" setting. Repeat this step for the remaining MAIN channels
- Right, Left Surround* & Right Surround*.
*A note about the surround level: If you are setting up a room
for a theatrical film application, which requires the surrounds to
be set for 82dBc each, instead of 85dBc. First confirm the SUR
SUB GAIN in the CAL CHANNELS menu is to the -3.0dB setting.
The calibrate the left and right surrounds for 82Bc each. For
more information, see page 7 "System Gain, Sub Offset & Level
Overview".
Step 3 Feed 40-80Hz pink noise signal to the CENTER channel only.
Adjust the subwoofer level control (on the back of the sub) and
"SUBWOOFER MAIN GAIN" in the "CAL CHANNELS" menu, until
you measure 85dBc. SPL should be measured in the same
way as was done for the center channel. The meter will bounce
around a little, so you will need to do a mental average (I tend
to filter out the peaks in my mind, so I don't set the sub too
hot). The other channels will measure about the same and no
additional adjustments need to be made using the 40-80Hz pink
noise signal.
Step 4 Turn off the pink noise signal, press the DOWN ARROW button
until the display reads "LFE MAIN GAIN" and press "+" (R) button
to set the LFE to +10dB (as recommended by Dolby). If you
want to confirm the LFE channel level or use the new LFE TRIM
feature, to make +/- 2dB adjustments in .5dB increments, send
the 40-80Hz pink noise signal directly to the LFE input on the
BMC. With the BMC MK III set to the "REF" setting, the level
should measure about 95dBc SLOW on an SPL meter. For more
information about the LFE TRIM, see page 7 "System Gain, Sub
Offset & Level Overview".
You are finished and the calibration process has been completed – enjoy!
Please make a note of all settings!