Rane DC 24 User Guide

RaneNote
SQUEEZE ME, STRETCH ME: THE DC 24 USERS GUIDE
Squeeze Me, Stretch Me:
The DC 24 Users Guide
• DYNAMICS 101
• THRESHOLD & RATIO CONTROLS
• COMPRESSORS & LIMITERS
• GATES & EXPANDERS
• SPLIT BAND PROCESSING
• GUITAR, BASS & RECORDING
INTRODUCTION
Compressors, expanders, and their cohorts – limiters and
gates, are all in the business of automatically controlling the
volume, or dynamics of sound. Lumped together they can be
called dynamic controllers, which would also have to include
your hand on the fader and the fat man dancing in front of the
midrange cabinet.
Used wisely, often in conjunction with each other or with
equalization or filtering, dynamic controllers can improve the
intelligibility of voice and the subjective effect of music. But
in the wrong hands they can sound terrible, and compressors
are the worst offenders.
Our goal is to de-mystify dynamic controllers as best we
can within the limitations of printed media. By understanding
a given tool's strengths and weaknesses, you can put it to it's
best use.
Roger Nichols - “I have used the DC 24 on every album
project I have done since I've had it”. He has had a DC 24
since 1988. Projects include mixdown on Riki Lee Jones
Flying Cowboys, recording and mixdown on Donald Fagens
Kamakiriad, and numerous others.
Walter Becker - “The DC 24 is great for bass and guitar. I
suggest you check it out”. Walter is a member of the popular
group, Steely Dan.
Jeff Davies
Dennis Bohn
Rane Corporation
RaneNote 130
© 1993 Rane Corporation
DC 24 Users Guide-1
DYNAMICS 101: A PRIMER
Let’s start with what a dynamic controller actually does.
No matter how you cut it, these are electronic volume
controls. It is a hand on a control, turning the volume down
and turning it up again. The hand is really quick and really
accurate, but it’s just turning a volume control.
SIGNAL CHAIN
Conceptually, dynamic controllers have two internal paths,
the signal and the side chains. The signal chain is the path the
main signal takes through the unit: through the input circuits,
the gain control device and then through the output circuits.
The signal chain goes through the “volume control” in the
“hand on a control” analogy.
SIDE CHAIN
The side chain is the hand which turns the control. Side
chain circuitry examines the input signal and issues a control
voltage to adjust the amplification of the signal. There are a
number of parameters governing side chain activity, but the
four most commonly discussed are threshold, ratio (or slope),
attack time and release time. Some dynamic controllers offer
adjustment of each of these parameters, while others have one
or more preset at an optimum setting for the application.
THRESHOLD
The threshold, like crossing through a doorway, is the
point at which gain adjustment begins. When the input signal
is below the threshold, a dynamic controller should be like a
straight wire. Above, the side chain asserts itself and turns the
volume down.
RATIO
Once the threshold is exceeded, just how far the volume
goes down depends on the ratio (or slope) setting. An
ordinary preamp or a straight wire has a ratio of 1:1, that is,
the output level tracks the input level perfectly. A 2dB change
at the input produces a 2dB change at the output. A severe
ratio is perhaps 8:1 or 10:1. For a 10:1 ratio, a 10 dB blast at
the input would rise only 1 dB at the output – heavy compression. Kinder, gentler ratios are in the 2:1 to 3:1 range.
ATTACK TIME
Attack time is the time which passes between the moment
the input signal exceeds the threshold and the moment that
the gain is actually reduced. Attack times generally range
between 1ms and 30ms.
RELEASE TIME
Release time is the time which passes between the rnoment
the input signal drops below the threshold and the moment
that the gain is restored. Typical release times are between .1
seconds and 4 seconds.
Some of the oldest compressors were called levelers, which
are becoming popular again.They had very slow attack times
and very long release times to provide volume adjustment of
overall program level for broadcast. If you shouted repeatedly, the level would slowly fall off for about 30 seconds,
then it would take another minute or so to recover.
DC 24 Users Guide-2
COMPRESSORS
A compressor, when the input signal reaches the level set
by the Threshold control, begins turning down the signal by
an amount set by the Ratio control. Most modern compressors
make the loud signals quieter, but do not make the quiet parts
louder. (However, by keeping the loud signals under control,
you can turn up the output level which will make the quiet
parts louder along with the rest of the signal.) Some compressor designs actually do raise quiet signals below the threshold. These designs might be called “upward expanders”.
LIMITERS
A limiter is a special form of compressor set up especially
to reduce peaks for overload protection. In other words, it is
a compressor with a maximum ratio. A compressor is usually
set up to change the dynamics for purposes of aesthetics,
intelligibility, or recording or broadcast limitations. Once the
threshold of a limiter is reached, no more signal is allowed
through. A limiter has a relatively high threshold, very fast
attack and release times and a very high ratio, approaching
infinity:1.
EXPANDERS
An expander is a compressor running in reverse. Above the
threshold, a compressor reduces the gain; below the threshold
an expander reduces the gain. A compressor keeps the loud
parts from getting too loud, an expander makes the quiet parts
quieter.
GATES
A gate is an expander with the ratio turned up. With the
proper settings (low threshold and a high ratio), a gate can be
applied to remove noise between louder sounds, and is often
called a noise gate for the way it can lock out background
noise.
GATE / EXPANDERS
A low ratio acts as an expander that turns quieter signals
down, while a high ratio acts as a gate that shuts signals off.
SIDE CHAIN EXTRA #1: SEND/RETURN
The gain control voltage is derived from the side chain
audio. If you were to put a signal with treble boost into the
side chain audio, it would not effect the treble in the main
signal path, but it would cause the high frequencies to cross
the threshold sooner or more often. Large peaks of treble
could be set to cause heavy compression with virtually no
compression at other times. What we’ve just designed here is
the basic de-esser, a circuit to remove excess sibilance. With a
bass boost you can make a de-thumper and with a midrange
boost a de-nasaler. Most compressors have a send and return
available in a side chain loop to patch in an equalizer for
these purposes.
SIDE CHAIN EXTRA #2: SLAVE
Many compressors and expanders make the side chain
control voltage available to connect to a neighboring unit, or
to tie internal channels together. This is called slaving or
linking the compressors, and it causes the units to compress
simultaneously when only one has an input over the threshold. This feature is normally used to preserve stable stereo
imaging, or to preserve spectral balance when the compressors are used in the high and low frequency ranges of a mono
signal.
THIS IS ALL VERY INTERESTING. SO WHAT’S THE
PROBLEM?
The problem is that heavy compression (low threshold and
a high ratio), almost always has nasty side effects. In the first
place, the timbre of the sound itself changes; it becomes
“hard” and “closed” and not nearly as sweet and open as the
sounds you envisioned when you got into this business.
Second, attack times optimized for pleasant compression will
not track initial transients quickly enough, and many instruments audibly suffer. Third, heavy compression will usually
be accompanied by “breathing,” i.e., the background noise
rises way out of proportion to the foreground sound as the
compressor releases. Bottom line: it just doesn’t sound good.
Take anybody’s compressor, run just about any sound
through it, compress it severely and run the results on Family
Feud: survey says, 89% of the audience won’t like it.
SO WHAT’S THE SOLUTION?
Many designs have appeared throughout the years to
produce gentle, smooth, natural-sounding compression. They
include tubes, FETs, VCAs, soft-knee compressors, electrooptical attenuators, and self-adjusting attack and release
times. Today, some digital workstations compress without
snipping transients, by looking ahead into the digital future. Is
that cheating or what? So what has Rane done to make its
compressors sound so great?
An independent panel of judges has studied Rane’s
compressor designs and unanimously decided there has been
no cheating. Rane has combined a number of perfectly even
handed, meat-and-potatoes ideas to make its compressors so
capable and transparent that we just seem like we’re not being
fair.
IDEA NUMBER ONE
Use self-adjusting attack and release times. The compressor and expander sections in the DC 24 change attack and
release times automatically to suit the program material by
using dedicated RMS-sensing ICs in the side chain. If the
input is predominantly low-frequency, the times are made
more gradual and slowed. If a quick transient comes flashing
down the wires, the times are tightened to deal with it. Our
experience has shown that attack and release controls, when
present, are confusing and easy to misalign.
IDEA NUMBER TWO
Combine an expander/gate function with the compressor.
The expander/gate, the compressor (and the limiter: see Idea
Number Three) in the DC 24 can be used independently, but a
big reason they are together is to share the work of clean
compression. An expanded or gated source of sound exhibits
less “breathing” when compressed. Instead of looking for
another patch cord when you realize you need a bit of gating,
you just turn a control.
IDEA NUMBER THREE
Combine a peak limiter function with the compressor.
Tracking with this idea of burden-sharing, Rane has put a
peak limiter in the same path as the expander and the compressor in the DC 24. With a limiter right there, you won’t be
asking the compressor to clamp the wild excursions. The
limiter, with auto-attack, auto-release and adjustable threshold
optimized, will play level police while the compressor
persuades more gently.
Rane designed a patented servo-locked limiting circuit,
which places the limiter within a servo loop and effectively
stops peaks from exceeding the threshold. The attack time
varies with the source material, but is never allowed to
produce diode-like hard clipping.
REALLY GREAT IDEA NUMBER FOUR, WHICH
DESERVES ITS OWN SECTION
Here’s the special twist in the DC 24: the two sections,
fabulous as they are, can also be assigned to different frequency ranges of the same channel of sound. This is not a
new idea, but it’s a great idea. In the past, the difficulty has
been that split-band compression has required a lot of
equipment: at least two compressors and a set of bandpass
filters per channel, or a very expensive difficult-to-set large
unit. What the DC 24 offers is not just innovative engineering
but a lot of powerful, interactive functions crammed into one
rack space.
SPLIT-BAND DYNAMIC PROCESSlNG
We haven’t talked much about split-band processing, but
it’s one of the easiest ways to compress transparently.
Broadcast stations have used split-band compression for
years, often dividing the spectrum into four or five bands.
When it’s done right, the radio station sounds great: loud,
present, with no squashing or pumping at all.
The great Dolby noise reduction systems, from Dolby A all
the way through B, C, S and SR, all use some variation on
compression, expansion and band-splitting. Dolby’s goal has
always been maintenance of the purity of sound, with no
artifacts of the processing. It works.
Split-band compression works well for several reasons:
You can optimize each set of dynamic processors (the
compressor, expander and limiter) to a particular range of
audio. That is, the ratio and threshold controls can be suited to
each part of the spectrum.
You can decide to process different ranges of an instrument differently. You could use no compression at all on the
low end of a bass, with heavy compression on the top end to
put the string slaps in balance with the bottom. Or you could
tighten the boomy bottom up with compression but leave the
top less controlled for that open feeling.
Any massive anomaly like a low frequency breath noise for
example, only triggers gain reduction within its range, leaving
the desired vocal unaltered. And the decidedly unmusical
phenomenon of a popped ‘P’ sucking the overall level back
10 dB is a thing of the past.
DC 24 Users Guide-3
Front Panel DUAL / SLAVE switch
DC 24
INPUTS AND OUTPUTS
TIP=#2=POSITIVE
RING=#3=NEGATIVE
SLEEVE=#1=SIGNAL GROUND
SEPARATE COMBINE -10 dBV
OUTPUTS
MADE IN U.S.A.
RANE CORP.
POWER
TIP=SEND
RING=RETURN
+4 dBu
CH 2 TRIM
CH 2
IN
CH 2 HIGH /
COMBINE OUT
CH 2
SIDE CHAIN
2-WAY CROSSOVER MODE
TIP=SEND
RING=RETURN
CROSSOVER
ENGAGE
-10 dBV
+4 dBu
CH 1 TRIM
CH 1 /
CROSSOVER IN
CH 1 /
LOW OUT
N108
CH 1
SIDE CHAIN
600mA
CLASS 2 EQUIPMENT
COMBINE MODE
LOW OUT
CH. 1
LOW OUT
CH. 1
CH. 1
CHANNEL 1
INPUT
CROSSOVER
COMBINED OUT
CROSSOVER
SUM
CH. 2
HIGH OUT
CH. 2
CH. 2
Figure 1. Results of the Separate / Combine and Dual switches in Crossover Mode.
1
1:
tio
Ra
Output Signal Level dBu
VISUALIZING ALL THIS
with each other to develop a dynamic curve. The solid black
Figure 1 shows a couple of different configurations,
depending on the positions of the Crossover / Dual / Combine line shows the curve produced when the controls are set as
shown.
switches that truly make the DC 24 a multi-function unit. It
In this example, the gate/expander circuit works on the
can be a two way crossover, with independent processing on
quiet parts, and the compressor and limiter work on the louder
the low and high outputs. The outputs can be summed with
parts. The gate/expander can range from just turning down
the Separate/Combine switch, and the Crossover can be
the quiet parts a little to a lot. The compressor and limiter are
switched in (see rear panel above), so that processing the low
a lot more flexible when used separately at different threshand highs separately can take place in a mono or send/return
olds, even though they have the same job of keeping the loud
application. Even though the outputs are summed at Channel
stuff under control. Got it?
2's output, Channel 1 is still outputting
+30
the lows which might be valuable to a
bass player running a full range along
+20
with a bass bin (see Figure 1).
Figure 2 shows how the gate/
+10
expander, compressor, and limiter all
Limiter Threshold
All input signal changes greater
can work together on the same prothan this setting, produce no
0
significant output increase.
gram material in a single channel. The
vertical axis is the output level, and the
Compressor Threshold
-10
Compressed
Limiter Ratio
All signal increases greater
horizontal axis is the input level. When
Output Range
At least 10:1, meaning a
than this setting are made
10 dB increase in input level
all Ratios are set at 1:1, the input and
smaller by the ratio amount.
results in no more than a 1 dB
-20
output of the circuit are the same as
increase in output level.
l
e
v
illustrated by the straight diagonal line
e
Compressor Ratio
tL
-30
Determines this slope. The output
pu
running at 45° across the graph. Each
In
change is less than the input change
No Processing
=
l
by the ratio amount. For example, a
e
of the Threshold controls acts like a
Output Range
ev
L
10 dB input increase produces only a
-40
ut
“hinge point”, activating gain reduction
5 dB output increase for a 2:1 ratio setting.
p
ut
O
only when the input signal reaches the
-50
Expander Threshold
level set by this control. The Ratio
All signal decreases less than this setting
are made bigger by the ratio amount.
controls how much of an “angle” the
Expander Ratio
-60
Expanded
Determines this slope. The output change
hinge will bend, or more realistically
Output
is more than the input change by the
how much gain reduction will occur
ratio amount. For example, a 5 dB input
Range
decrease produces a 10 dB output
-70
once the threshold is reached. Graphidecrease for a 2:1 ratio setting.
cally, the ratio can swing this hinge
-80
Input Range
No Processing
Input Range
from 45° (no processing) to almost 90°
Gate Threshold
Input Range
to Compress
to Expand
(full ratio). It is also possible, by
All signal changes
than this setting
adjusting the Thresholds, to have each less
essentially produce
-70
-60
-50
-40
-30
-20
-10
0
+10
+20
+30
zero
output, i.e., the
Input Signal Level dBu
of these circuits overlap and interact
output is muted.
Figure 2. Compressor / Limiter / Gate Input to Output Graph
DC 24 Users Guide-4
DC 24 APPLICATIONS
STARTING OUT
Sometimes it's neccessary to start from scratch. The panel
above shows where the controls should be for no processing.
Then you can adjust each section one at a time.
TWO CHANNEL COMPRESSOR/LIMITER
In this case, the audio path on channel 1 is completely
separate from channel 2, allowing you to use it as a stereo
unit or for doing two completely different processes to two
completely different signals. For stereo use, the front panel
has a “Dual/Slave” mode switch that allows you to slave
channel 2 to channel 1. This assures that both signals are
affected identically. In this application, the crossover is
disengaged (this button is located in the middle of the rear
panel.) The “Separate/Combine” switch on the rear panel
should be in the “Separate” mode. Set the rear panel “-10/+4”
switches accordingly, depending on whether you are running
your system at -10 dBV or +4 dBu levels.
CROSSOVER WITH BUILT-IN LIMITING
Let’s say that you want to run a bi-amped system and
process the low end a little differently than the high end. This
is a handy way of saving your woofers from over-excursion.
In this application the crossover is engaged and set at the
recommended crossover point for your speakers, let’s just say
1.2k for the sake of example. In this instance the Separate/
Combine switch on the far left of the rear panel is set on
Separate. Your input would connect to the Channel 1 input
jack. This gives you a separate output on Channel 1 (signals
below 1.2k, the “lows”) and everything from 1.2k and above
on Channel 2 (the “highs”). This setup allows you to better
contain the low end without unnecessarily limiting the high
end. A crossover and a processor all in one rack space!
GUITAR
John Albani (Canadian Musician Magazine)- “By now,
I’m sure that you have heard that a low stage volume is
essential to your sound man getting a better house mix. Well,
here are a few suggestions on how to achieve a lower volume
without sounding like you’re playing out of a transistor radio.
“Marshalls and other 4 x 12 cabinets give a great ‘chunky’
sound, but it is also accompanied by an annoying ‘woofing’
on the lower end. This stereo compressor has the unique
feature of becoming a two-way crossover with independent
low end and high end compressors. With this I was able to
achieve what was previously only possible with the dynamics
section of the SSL console that was used for my guitar sounds
on the Lee Aaron “Bodyrock” album. Take the preamp output
of the loop into the DC 24 Channel 1 Input. The Channel 2
Output should return to the main amp input of the effects loop
or the power amp (via your effects). Set the switches to Dual /
Crossover / Combine. Now you can set a crossover point on
the front panel (try around 400 Hz) and compress the bottom
end at a 10:1 ratio. While chugging on a chord where you
notice a lot of woofing, set the gain reduction with the
Threshold control to read 6 dB. When you hit an open chord,
there should be no gain reduction. If there is, back off on the
Threshold, not on the Ratio. Now compress the top end
between a 1.5:1 to 2:1 ratio, with 3 dB gain reduction when
an open chord is hit, to give your sound a lot more attack.
Also, no matter where you play on the neck, the bottom end
of the sound will be even, without woofing, giving your
overall tone punch and clarity.
“Warning: Do not over compress the top end or the pick
attack will be slurred. If you want to hear more attack, turn up
the top end Level of the DC 24 after setting the abovementioned compression for the top end.
“Right now you are 99% on your way to retaining your
sound or bettering it, without blasting everyone to
Palookaville, or deafening your sound man.
“On stage you must work within the tonal range of your
instrument. I hear guitarists with huge sounds that are great
until the bass player fires up. He can’t hear because the
bottom from the 4 x 12s is blurring out his bottom end. So
you end up in a volume war, which puts you out of the front
mix. Try this: Once you have the sound you like, back off on
the bottom Level control of the DC 24. Your bass player is
already operating in that tonal range and you won’t miss the
sub lows when he’s playing with you anyway.”
BASS
Now for you bass guitar players out there...How many
times have you been yanked out of the mix by your
soundman because you’re overdriving the system? You’d
love to be able to keep the high-end attack without booming
on the low end. Well, try this. Set the switches to Crossover
in, Separate/Combine to Combine, and Dual Mode on the
front panel. Now, plug into Channel 1 from your preamp
output, and come out of Channel 2 into your amp. What you
have done is split your mono signal, with a crossover point,
then you’ve run it through separate processors and combined
the signal back together on the Output of Channel 2.
Where does the unit go in the signal chain? Well, that
depends on how you want it to function. If it’s a comp/limiter
for the input signal, it would go after the bass (if the bass has
a line-level output) and before the preamp. If it’s to function
as a limiter to protect the speakers in the bass rig, it would go
after the preamp and before the power amp. Another method
DUAL
CROSSOVER ENGAGE OUT
(REAR PANEL)
GATE EXPANDER
POWER
-20
0
3
7
8
2
-40
-50
COMPRESSOR
4 5 6
-10
-30
10
THRESHOLD
1
10
(:1)
RATIO
-20 -10 0
-30
10
20
THRESHOLD
1
10
(:1)
RATIO
0
+6
+20
THRESHOLD
0
6
12
-20
CH 1 OUTPUT
LOW
3
0
-6
4
1.1
-40
-48
LIMITER
1.4 1.6 2
1.2
3
-6
BYPASS
24
GAIN
REDUCTION
+6
-12
SIG
+12
LEVEL OL
CROSSOVER
200
400
800
150
1.2k
125
2k
MODE 100
90
4k
75
6k
70
7k
DUAL
SLAVE
FREQUENCY
GATE EXPANDER
-20
0
3
7
8
2
-40
-50
COMPRESSOR
4 5 6
-10
-30
10
THRESHOLD
1
10
(:1)
RATIO
SEPARATE
-20 -10 0
-30
10
20
THRESHOLD
1
10
(:1)
RATIO
0
+6
+20
THRESHOLD
0
-6
6
12
-20
CH 2 OUTPUT
HIGH
3
0
-6
4
1.1
-40
-48
LIMITER
1.4 1.6 2
1.2
3
DC 24
DYNAMIC
CONTROLLER
24
GAIN
REDUCTION
+6
BYPASS
-12
SIG
+12
LEVEL OL
“Straight Wire” Setup
DC 24 Users Guide-5
DUAL
CROSSOVER ENGAGE IN
(REAR PANEL)
GATE EXPANDER
POWER
-20
0
3
7
8
2
-40
-50
COMPRESSOR
4 5 6
-10
-30
10
THRESHOLD
1
10
(:1)
RATIO
-20 -10 0
-30
10
-48
20
THRESHOLD
1
10
(:1)
RATIO
0
+6
+20
THRESHOLD
0
6
12
-20
CH 1 OUTPUT
LOW
3
0
-6
4
1.1
-40
LIMITER
1.4 1.6 2
1.2
3
-6
24
GAIN
REDUCTION
+6
BYPASS
-12
SIG
+12
LEVEL OL
CROSSOVER
200
400
150
800
125
1.2k
2k
MODE 100
4k
90
6k
75
70
7k
DUAL
FREQUENCY
SLAVE
GATE EXPANDER
-20
0
3
7
8
2
-40
-50
COMPRESSOR
4 5 6
-10
-30
10
THRESHOLD
1
10
(:1)
RATIO
COMBINE
(UNLESS
BIAMPING)
-20 -10 0
-30
10
-48
20
THRESHOLD
1
10
(:1)
RATIO
0
+6
0
-6
6
12
-20
CH 2 OUTPUT
HIGH
3
0
-6
4
1.1
-40
LIMITER
1.4 1.6 2
1.2
3
THRESHOLD
GAIN
REDUCTION
DC 24
DYNAMIC
CONTROLLER
24
+20
+6
BYPASS
-12
SIG
+12
LEVEL OL
Bass Guitar Setup
is to insert the unit in the effect loop of the preamp. This
allows the bass signal to be affected by the pre-amp first, then
the comp/limiter, and then sent to the power amp. This can be
desirable with tube pre-amps.
This unit can also be used for biamp rigs. For this, it is
placed in the signal chain after the preamp and before the
power amps. The output from the preamp is the signal that is
processed and split at the selected crossover point. For biamp
purposes, the Combine/Separate switch should be in the
Separate position. Channel 1 processes the lows and channel
2 processes the highs. The low and high outputs are independent and correspond to Channels 1 and 2.
The DC 24 has two great advantages over other compressors–the crossover and the dual channels. It gives you
complete control of the signal and processing of it. This is
something that wasn’t available before in a single unit. One
stereo or two mono comp/limiters and one crossover would
be required to do what the DC 24 does in a single rack space.
This unit solves many compressor blues. For more attack, you
can turn up the Level on the top end. Notice that when you
stop playing, that amp buzz and hiss goes away. Nice, huh?
Dave Freeman (Bassics Magazine)- “I tested this unit in
the combine mode with the crossover set at 200 Hz. I used my
4 string Music Man bass, famous for its ear splitting high end,
as test in different channel settings. I set Channel 1 (low end)
for mild compression at 2:1 with the Threshold at -10 dB. I
set Channel 2 (high end) for heavy compression at 6:1, and
the Threshold at -20 dB. I turned the volume and the treble
controls on the bass on full, and slapped and popped like a
madman. So what happened? Well, the high end was compressed down to the low end level. The sound was balanced
and didn’t have a compressed tone. I could slap away ‘til my
fingers went numb without having the comp/limiter clamp
down on the entire signal. Impressive results!
“I then tested the unit with my 5 string Ken Smith bass. I
set the lows for mild compression at 2:1 at -20 dB Threshold.
I set the high end for the same compression but with the
Threshold at -10 dB. I wanted just a bit on the bottom for the
low B string and less processing on the highs. I slapped and
popped on all the strings including the low B. The result was
slight processing on the lows which tightened the bottom, but
didn’t make it sound controlled or processed. The highs had
subtle compression that sounded natural, unlike others that
‘breathe’ when compressing.”
RECORDING
Use it on bass guitar, piano, drums, vocals–anywhere
you’ve used a compressor/limiter before. The DC 24 gives
you more control and a less tortured sound. In fact, split-band
processing works so well that a DC 24 sounds good compressing an entire mix (two required for stereo in split-band
mode).
Of special interest are instruments which have large level
differences in their different tonal ranges. String pops on a
bass are one, but flute is another. The higher tones require
more breath and are much louder than the lower. Another
good application would be a drum mix or submix. A splitband compressor does a better job of smoothing the performance out.
Roger Nichols (Engineer)- He uses the DC 24 primarily on
bass and guitar. He sets the Crossover at 100 Hz, the Gates
and Compressors to 1:1, and engages the Combine and Dual
Mode switches. This gives him separate Limiters to control
the high and low peaks separately on a mono signal.
Brent Hurtig (EQ Magazine)- “In the studio, the crossover
has some different applications. With Combine selected and
the Crossover engaged, a signal entering Channel 1 is split
into two bands. These two bands again may receive separate
processing. What’s different here, though, is that the two
bands’ signals are merged at the Channel 2 Output. This little
exercise allows you to apply different amounts of compression and limiting to the low and high ends of a piano. Or let’s
say the saxophonist sounds great, but every time she hits the
high C she pins the meters: Just the high end of the sax could
be limited. Very clever.
“You also can use the Separate mode in the studio. With
this setting, the crossover acts like a low pass filter to signals
in Channel 1, and like a high pass filter to signals in Channel
2. We found some great sounding guitar, vocal, and keyboard
tones using the DC 24 in this equalizer-like manner.”
Digital Recording: Use it to compress an extremely wide
dynamic range into a signal that won't go into digital overload, i.e. clipping. The limiter is the primary circuit here to
keep things under control, but a little compression with its
threshold set just under the limiter threshold setting will help
keep the limiting even more subtle. Also, the gate can be set
just above the noise floor with a low threshold and high ratio
to remove mixer or tape hiss between cuts. To control a stereo
mix, set the switches to Normal / Separate / Slave.
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 TEL (425)355-6000 FAX (425)347-7757 WEB http://www.rane.com
DC 24 Users Guide-6
DOC 103168 PN 05140