BLUE SKY BMC MK III User Manual page 14

SYSTEM ACOUSTIC LEVEL SETTING - INSTRUCTIONS FOR USING
FULL -BANDWIDTH PINK NOISE (using MOVIE / DVD RELEASE level
settings for this example)
PLEASE NOTE: These instructions are designed for those users that have
a real time analyser (minimum resolution 1/3 octave). If you do not have a
real time analyser, please use the directions on page 13, for the bandwidth
limited pink noise test files.
Step 1 TURN OFF THE SUBWOOFER.
Step 2 Press the MENU button twice, or until the display reads "CAL
CHANNELS".
Step 3 Place the measurement microphone at the reference monitoring
position, at or near ear level. Depending on the measurement
microphone, it may need to be pointed toward the ceiling or
toward the source (depends on the calibration method of the
microphone). Please consult the manual for the microphone or
analyzer for more information regarding this.
Step 4 Turn the gain knob on the remote to the "REF" setting, as
determined in the section titled "SETTING REFERENCE GAIN" on
page 13. Assign the full-bandwidth pink noise signal to the left
channel. Push the up arrow button 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). If you are using a
1/3 octave analyzer (RTA), 85dBc is equal to aligning the level
of the speakers to the 70dB reference line on the analyzer, as
shown in Figure 3.
Confirm that the master gain setting has not been changed
from the "reference level" setting.
remaining MAIN channels - Center, 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 5 TURN ON THE SUBWOOFER AND POWER OFF THE OTHER
MONITORS (L,C,R, LS and RS).
Step 6 Confirm that the gain knob on the remote is set to the "REF"
setting, as determined in the section titled "SETTING REFERENCE
GAIN" on page 13. Press the MENU button twice, or until the
display reads "CAL CHANNELS". Press the UP (C) button until the
display reads "SUBWOOFER MAIN GAIN". Assign the full-bandwidth
pink noise signal to the CENTER channel only. No noise should
be coming from any of the satellite speakers (they should be
turned off). Now, using a 1/3 octave RTA, align the level of the
subwoofer to the 70dB reference line on the analyzer (this will
measure approximately 79dBc SLOW - as shown in Figure 4 - this
is because of the limited bandwidth of the subwoofer).
Page 14 • User Manual • 5.1 System Calibration (continued)
BMC MK III
USER MANUAL • 11 • 5.1 SYSTEM CALIBRATION (CONTINUED)
Repeat this step for the
FIGURE 3
FIGURE 3
85
5.1 Channel Calibrated System Response
80
LFE Channel +10dB
75
above Main Channel
Ref
80 dB Ref Line for LFE = Approximately 89dBC
70
70dB Ref Line = Approximately 85dBC for each main & surround
Bass-Managed
Subwoofer
Channel = 79dBC
65
60
55
Test Signal = 0dB VU Full Bandwidth Pink Noise / -20dB FS (Full Scale Digital)
Measurement System = 1/3 Octave Real Time Analyzer
50
45
FIGURE 4
BASS-MANAGED SUBWOOFER (not the LFE channel)
= 79dBC
L =
85dBC
LS =
85dBC
Test Signal = 0dB VU Full Bandwidth Pink Noise / -20dB FS (Full Scale Digital)
Measurement System = SPL Meter set to C Weighted & Slow
Reference Monitoring Position
5.1 Channel Monitoring System
Step 7
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 full-
bandwidth 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 89dBc SLOW on an SPL meter and the pass band
response of the SUB should average around the 80dB reference
line on the 1/3 octave RTA, as is shown in Figure 3.
For more information about the LFE TRIM, see page 7 "System
Gain, Sub Offset & Level Overview".
The calibration process is now complete, please make a
note of all the settings!
channel
C =
85dBC
R =
85dBC
RS =
85dBC