B" Chain Alignment; Channel Confi Guration; Headroom Settings; Main Channels - Usl JSD-80 Manual

Section 9 "B" Chain Alignment
9.1 Channel Confi guration
Selecting "File" in the menu bar will produce
a drop down box. Click on "Input Confi gura-
tion".
The processor supports either fi ve screen
channels or "Ex" back surround channels
but not both.
Select the appropriate confi guration and
click "OK".
Note: This confi guration will affect the
equalizer and format panels.

9.2 Headroom Settings

Selecting "File" on the menu bar will pro-
duce a dropdown box. Click on "Headroom
Adjustment".
Select one of the three settings. Generally,
26 dB of headroom is suffi cient provided
there is not more than 6 dB total boost be-
tween bass and low frequency
fi lters or between treble and high frequency
1/3 octave fi lters. For instance, if the bass
slider is set at +3 dB and any of the 1/3 oc-
tave eq bands from 40-125 Hz are boosted
more than 3 dB, the headroom will be com-
promised.
Selecting 29 dB headroom would allow a full
6 dB bass boost plus up to +3 dB boost in
any of the 40-125 Hz bands.
In each case, it is the total boost that im-
pacts the headroom. For 26 dB, the maxi-
mum boost is 6 dB; for 29 dB, the maximum
boost is 9 dB; for 32 dB, the maximum boost
is 12 dB.
3rd Edition. February, 2006

9.3 Main Channels

Left, Center, Right, Left Surround, Right Sur-
round, (Left Center, Right Center or Back
Surround Left, Back Surround Right).
Before proceeding with the room equaliza-
tion it is imperative that the loudspeaker
and crossover systems be properly aligned.
Issues like speaker phasing and horn tilt
need to be checked. When using crossovers,
the low, mid and high frequency drivers
must be balanced to produce a relatively
even response from 100 Hz to 5 kHz.
1. Set up an external REAL TIME ANA-
LYZER or the internal JSD-80 REAL
TIME ANALYZER with the microphone
two-thirds of the way back and one-
third of the way in from the side of the
auditorium. If a multiple microphone
system is being used (such as the USL,
Inc. MMP-10), set up the microphones
according to the instructions provided
with that system. Set the MAIN FADER
to "7.0." Access the channel output
controls on the Output panel on the
JSD-80 Laptop Interface Software.
1/3 octave
When aligning the auditorium for the
fi rst time with the JSD-80 Laptop Inter-
face Software, it is recommended to
set all the channel gains to minimum,
click the "Pink Noise" radio button
in the Signal Generator box, click the
"Pink" checkbox under the left channel
slider, then exit the Output Screen to
the Equalizer Screen for the frequency
alignment.
Note: When using the generator, the de-
fault mode allows one active channel
at a time. Holding down the control key
allows selection of multiple channels for
Page 29 USL, Inc. JSD-80 Instruction Manual