Lexicon DC-1 Supplementary Manual page 39

DC-1 Theory
and Design
The DC-1 allows you to create virtu-
ally any acoustic space you desire. It is
extremely simple to walk through the
parameters of a program, vary them to
your liking, name the space, and store it.
For this example, let's do a fairly radical
redesign — changing CATHEDRAL
into a reverberant hall. Begin by select-
ing CATHEDRAL, the most reverberant
DC-1 effect.
Think about a nice concert hall
where you would enjoy going out to see
your favorite performer. Consider a hall
of approximately 2,700-3,000 seats
with a balcony (and, of course, valet
parking). Get your performer's CD, cue
it up in the CD player, but don't start it yet
— we'll design the hall first.
First, let's decide how long the hall is,
as this will influence the reverb time and
the overall character. Using the MENU
buttons, enter the EFFECT ADJUST
menu, select HALL SIZE, and set it to 35
meters (meaning the simulated hall will
be 35 meters long).
How close to the stage do you want
to sit? Might as well go to the good
seats— how about row M in the center of
the orchestra section? Predelay ap-
proximates the amount of time between
the original sound of the performer and
the sound of the hall. The closer you are
to the stage, the longer it will take for the
sound to bounce off the back walls and
get back to you. Let's add a little extra.
(Some predelay is inherent in the mode
to keep the direct sound distinct.) Using
the MENU buttons, set PREDELAY to
64ms.
The Speech Detection feature is ac-
tually a special dialog recognition pro-
gram which reduces the reverberation
on spoken voice. As we aren't using the
radio (and, therefore, have no announc-
ers or commercials), let's turn Speech
Detection off by pressing MENU
Think about what the walls look like
in a good concert hall. Many irregularly
shaped objects like elaborate columns,
carved panels, draping and light fixtures
come to mind.
36
Creating a Custom Concert Hall Seat
These objects absorb and diffuse
the sound. A good sounding space
never has a lot of high frequencies
bouncing back at you. Select
ROLLOFF to manipulate this part of the
hall. Change the value to 2.2kHz.
Next, select MID RT. The reverb
time of a space helps describe how
large it is. For example, a cathedral has
a much longer reverb time than a living
room. Let's modify the reverb time of our
factory preset to an appropriate value. A
hall of the size we are creating will have
a reverb time of approximately 2.00 sec-
onds for the mid frequencies.
BASS RT describes how long the
low frequencies of the hall stay around
relative to the midrange. You have three
choices: 1.25 (warm), 1.0 (neutral), and
0.7 (dry). Typically, a hall of this size will
have a little longer bass reverb time.
(Hence, the preset value of 1.25.) This
one is your choice — use MENU
to change the value.
.
Lastly, hold the Back BALANCE but-
ton down to move the balance all the
way to the back. Now it's time to listen to
your creation. Start your CD. It should
sound like you are standing in the lobby
of the hall with the doors closed. Slowly
move the balance to the front of the hall
one step at a time by repeatedly press-
ing Front BALANCE. (Don't hold it
down.) You are now walking down the
aisle to take your seat. When the sound
feels right, stop pressing the balance
key and "take your seat." If you want to
make the effect even more dramatic,
increase EFFECT LEVEL (in the EF-
FECT ADJUST menu).
To rename your new hall, use MENU
to select CUSTOM and scroll to EF-
FECT NAME. Use MENU
change each letter. Use SELECT to
move to another character. Once you've
named your hall, press DONE to exit the
menu. Your settings and new name are
and
automatically stored in place of the fac-
tory program CATHEDRAL. If you want
to restore the factory settings, go to the
CUSTOM menu for your new effect and
select RESTORE PARAMETERS.
Press SELECT to erase your settings
and restore the CATHEDRAL param-
eter settings. Select RESTORE EF-
FECT NAME and press SELECT to
change your effect's name back to CA-
THEDRAL.
It's fun, and pretty easy, to create
almost any acoustic space you want.
For the megalomaniacs among you try
creating your own private Taj Mahal —
in the CATHEDRAL effect, increase
MID RT to 17.04 and turn EFFECT
LEVEL all the way up. Play a CD for a
couple seconds, then hit pause and
close your eyes ... Just remember, you
can't hurt anything by experimenting,
and the factory presets can't be perma-
nently modified, so don't worry about
losing them forever.
Enjoy!
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