USL, Inc.
JSD-80 Instruction Manual
Page 31
3rd Edition. February, 2006
2. Study the Subwoofer response on the
RTA. The parametric will allow you to
smooth the dips or take out bumps in
the response from 20 to 100 Hz. Adjust
the FREQ slider to the same frequency
as the peak. Set the Q control to about
4. Adjust the equalizer gain until re-
sponse becomes fl atter at the selected
frequency. Adjust the Q control to
widen the effect of the equalizer to
achieve the best, fl attest response. It
may be necessary to slightly readjust
all the three controls until the best
results are achieved.
3. Select the output screen and select
both the center and subwoofer pink
noise by holding down the “Ctrl” key
and checking the boxes. The subwoof-
er should fi ll in the lowest frequencies
and create a smooth overall response
on the RTA from 25 Hz to 1 kHz. It may
be necessary to adjust the subwoofer
channel gain. It also may be neces-
sary to click to phase invert on the
subwoofer to be sure that the low fre-
quencies of the center and subwoofer
are adding rather than subtracting.
Set the fi nal subwoofer level so that
its horizontal display (20-100 Hz) is
10 dB ABOVE the horizontal display of
the center channel on the REAL TIME
ANALYZER.
9.5 Optical Subwoofer
1. Once the subwoofer channel is equal-
ized and the level set, it is time to trim
the optical subwoofer parameters.
2. Turn off the pink noise generator.
3. Thread a pink noise loop Cat 69 P or
equivalent on the projector and select
mono.
4. Set the optical subwoofer frequency
to 50 or 60 Hz.
5. Using the auditorium microphone note
the level of the pink noise from the
center channel.
6. Adjust the optical subwoofer gain so
the subwoofer output is on the same
horizontal line as the center channel
on the REAL TIME ANALYZER.
9.6 Saving Settings After
Alignment
After completing the alignment, the con-
fi guration you have setup should be saved
to the onboard DSP Flash RAM. To do
this, choose the Disconnect icon from the
toolbar or Disconnect from the Communi-
cation menu.
You will be prompted with the following
screen providing several save options.
Clicking “Yes” will save your current set-
tings to the JSD-80 and then verify that they
were correctly saved to the unit. Choosing
“No” will keep you connected to the JSD-80
