Studio Technologies ISS - Manual (Page 21)

Issue 3, June 1990 ISS User Guide
Page 22 Studio Technologies, Inc.
ISS
Bypass mode, putting the simulator cards
out of the broadcast chain. (This does not
mean removing the ISS from the audio path
by the use of the I/O Bypass mode!) If you
wish to check the ISS with the Stereo Simu-
lator cards in the broadcast chain, you need
to use pink noise. The randomness of pink
noise will allow left verses right frequency
response observation. Studio Technologies
uses pink noise for testing the Stereo Simu-
lator cards.
The Sound of the ISS
The ISS has been factory adjusted to give
what we feel is a very good overall simu-
lated stereo “sound.” We spent a lot of time
doing listening tests with music, voice,
sound effects, and actual television audio
signals. If you feel you must adjust the ISS
stereo simulators, provisions have been
made for you to do so; trimmer potentiom-
eters (trim pots) are buried behind the front
cover, but are accessible. The simulated
stereo is created by the two stereo simula-
tor cards. The Type I Card is located in card
slot 2. The Type II Card is located in card
slot 4. Trim pot R43 on the Type I Simulator
Card controls the amount of simulation on
the full audio bandwidth. It is factory set at
50% of its rotation. Trim pot R43 on the
Type II Simulator Card controls the amount
of simulation over the upper and lower
portions of the audio band, but simulates
little on the voice band. It is factory set at
50% of its rotation. The outputs of the Type
I and Type II Simulator cards are combined
in the Crossfade Card to form the simulated
stereo signal you hear.
The following is a suggested procedure for
resetting the Stereo Simulator cards. You
should have a wide variety of sample pro-
gram material available, especially men’s
and women’s voices and music with a very
wide frequency range. Remove the ISS front
panel by removing the four knurled screws.
Place the ISS in the SIM LEFT manual
mode. The trim pots to be adjusted are
located near the front of the simulators
cards. The cards do not have to be re-
moved, nor the ISS power turned off, for
pot adjustment. However, you will need
a small screw driver and a little care. Turn
trim pots R43 on both simulator cards fully
counterclockwise. This turns off all stereo
simulation. Feed a voice signal into the ISS
left channel input. Listening in stereo to the
ISS left and right audio outputs, you should
hear the left input audio coming from both
the left and the right outputs, i. e., you
should be hearing two channel mono.
On the Type I Simulator Card, adjust R43
clockwise until an acceptable amount of
simulation is heard. Listen to make sure
that the voice does not sound over-
processed. Better too little simulation than
too much. Use the factory setting of 50%
pot rotation as a reference. Now feed a high
quality audio signal into the left input. By
high quality, we mean a music source that
has lots of low and high frequency content.
On the Type II Simulator Card, adjust R43
until your desired amount of simulated
stereo is heard. Listen carefully to the low
and high frequencies as this is where the
Type II Card is adding its affect. Switch
back to feeding voices and make sure they
still sound good. If they sound too affected,
adjust Type II R43 counterclockwise until
the voices again sound good. Go back to
the music, the simulated stereo should still
sound good. Confirm your settings by
doing listening tests with many different
audio signals, especially a wide variety of
voices. Once you are satisfied with your
settings, cut out this section of the manual