FMR RNC Compressor FAQ - Frequently Asked Questions
MOST FREQUENTLY ASKED QUESTIONS
I hate wall-warts, why does the RNC
have a wall-wart?
First, let me assure you that, as users, we have no love of wall-warts
either! There are, however, some reasons for using them with the RNC:
1) Reduce hum/noise interference between the RNC's audio circuits and
an internal power supply (it's a very small package), 2) Improve the
universality of the RNC for an international market (the only thing
that's different between the RNC U.S. and RNC Australian is the
wall-wart; no internal changes are necessary), 3)
Simplifying/circumventing governmental approval of the RNC's power
supply by using an already approved power supply and, 4) There's little
room inside the small cabinet (used to keep the costs down) for a
transformer of adequate margins.
Why is the RNC unbalanced instead
You'd think the answer to this one would be a simple "to keep costs
down". Although that's one of the reasons, there's another reason
that's less obvious and the primary one: we designed the RNC to be used
in home studios (like ours) made up primarily of unbalanced pieces. So,
we designed it to easily interface to equipment usually found in the
intended environment. For example, many home studios use mixing boards
that have single Tip-Ring-Sleeve insert points on their input channels.
We thought that it'd be neat, convenient and show unambiguous support
for this studio type by allowing the RNC to be hooked directly to these
inserts with single TRS cables. If the I/Os were balanced, we wouldn't
be able to do that.
Can the RNC be rack mounted?
Yes! For rack mounting, the RNC has a #10-32 nut in its base that can
be used in conjunction with a universal rack tray to mount the RNC (up
to 3 on one tray) in a standard 19" rack.
For applications where you want to just set it on
something (if you've got the available surface area...ours are always
covered with notes, cassettes, DATs, pencils, sheet music, patch cords,
etc), we've included nice little non-marring rubber feet.
Why does the RNC distort my bass
At the risk of sounding too esoteric and philosophical, there are many
universal laws that are, many times, inconvenient (like, say, gravity).
Well, there's a mutual (and universal) exclusivity between low
frequency fidelity and fast compressor release times. Stated another
way: the faster a compressor's release time, the more distorted the
lower frequencies will be. "Okay, okay!", you say, "I know that! But
why don't I have similar problems with my other compressors?" Simply
put, the RNC's normal mode release times are shorter than many
compressors (some of the fastest that we've seen). This means that the
RNC will induce low frequency distortion more frequently than your
other compressors. "Why didn't you make the RNC so it wouldn't distort
my bass notes?" Because then we'd limit (no pun intended) your creative
choices for other sound sources where a really fast release time would
sound really gonzo...like on kick or snare drums. Try compressing a
snare drum track with the RNC set for really fast attack and release
times. You'll here drum resonances that you've never heard before that
can be creatively used to add spice to your mixes!
"How do I avoid or reduce the low frequency
distortion?" This one's easy: increase the release time until the
distortion goes away. (Doing my best Groucho Marx impression: "Does it
distort when you do that? Well don't do that!")
On some sound sources, the RNC
really "pumps and breathes". What can I do to reduce the pumping and
There are several things you can do:
into SuperNice mode
the total gain reduction amount
the compression ratio
the attack time
the release time
The simplest of the bunch is to just switch into
SuperNice mode. The other solutions will vary depending upon eachother.
In general, you'll want to experiment to see which of the parameter
changes gives you the effect (or lack thereof) that you want. Some of
the pros that we talk to tend to keep the total gain reduction to 6dB
and under (sometimes only 2dB!). They also tend to not use the other
parameters in extreme settings (for example, one of our pro users who
uses the RNC on acoustic guitars, swears by a RATIO of less than 2:1
and gain reduction amounts less than 2dB).
Is the RNC a peak, average or
Yes! Actually, the RNC uses aspects of all three depending upon the
mode. In the NORMAL mode, the RNC is a peak responding compressor only.
Peak-responding compressors tend to have the most extreme
characteristics. We wanted to give you the ability, within one
compressor, to choose between really colorful compression if you wanted
it — so the peak detection for this mode was our first choice
for NORMAL mode — as well as smooth, neutral-sounding
compression (i.e., SuperNice mode). For the smooth part — the
SuperNice mode — the RNC is utilizes parts of all three
detection schemes. The details of this are very nerdish and boring, but
suffice to say that the SuperNice mode gives you the smoothness of an
RMS and average-responding compressors (some say even more smoothness)
in tandem with the signal control of a peak-responding compressor.
Does the RNC have hard-knee or
In both the Normal and SuperNice modes, the RNC is mostly a
hard-knee compressor with just a touch of "softness" around the
threshold point. BUT, this "softness" is very confined and predictable,
so that if you're using the RNC in Normal mode, it
responds more like a hard-knee compressor. Even though this same level
of softness/hardness is used in the SuperNice
mode's detector, there's enough other stuff going on to keep the SuperNice
mode sounding very gentle (like seeing fluffy little white clouds on a
sunny day while eating marshmallows... um... sorry...)
What cable/connector types should I
use to hook up the RNC?
There are three initial questions:
1. Am I hooking the RNC up to an unbalanced piece of gear?
2. Am I hooking the RNC up to a balanced piece of gear?
3. Am I hooking the RNC up to special connections, like Mackie channel
Once you know the answer to these questions, you
can plan the type/quantity of connectors that you'll need. However, one
thing is for sure: you'll be hooking into the RNC with either a
standard 1/4" phone jack (Tip-Sleeve, or TS) or a 1/4" stereo phone
jack (Tip-Ring-Sleeve, or TRS). The other end of the cable will be
determined by the piece of gear that you're hooking the RNC to and it's
(the other gear) connector/electrical interface requirements. If
you're hooking up the RNC inputs to a balanced source, we strongly
recommend that you get the source equipment manufacturer's to advise
you on the best way to do this. There are some output circuit and
hook-up combinations that could damage your source equipment if you're
Connecting the RNC to unbalanced
This connection configuration is the most straight-ahead.
Connecting the RNC to balanced
Here are the cable connections necessary to hook up the RNC to balanced
equipment that uses XLR connectors.
For most of the balanced
equipment you'll use, these cables are wired like this:
||HOT (pin 2)
||COLD (pin 3)
There are several off-the-shelf cables that can be
bought already configured this way (Example: HOSA PXM-105 and HOSA
PXF-105). Check with your local dealer about their recommended choices
for these cables.
This all assumes that your equipment can tolerate
connecting the COLD (Pin #3) to ground (some can't). So, to be on the
safe side, please check with the manufacturer to make sure that you can
hook up your balanced outputs this way.
Connecting the RNC to TRS Console
A unique aspect to the RNC's wiring is that it will connect to some
console inserts — connecting both a single channel's input
and output — with a single TRS cable:
Click here for more detail on balanced
connections than a sane person would ever want.
Can I use the RNC for my stereo mix
Yes. In fact, the RNC's SuperNice mode was designed for and tested
extensively with stereo program material. One of our goals was to have
a 2-mix compressor that sounded good, gave some signal control and
didn't cost gobs of money. So, how should you hook it up to your mix
bus? Probably the best way is by hooking it into your console's stereo
bus inserts. BUT, you could always take the simplest approach and just
take the output of the mixer, connect it to the RNC's inputs and then
connect the RNC's outputs to your monitoring system. Just follow some
of the guidelines we've given you above (and follow hook-up
instructions of the equipment you're hooking the RNC to).
What's the RNC's sidechain function
There are a few additional effects/functions that compressors can
provide. De-essing and ducking are two that immediately spring to mind.
Both of the these functions require access to particular parts of a
compressor's innards so they may be connected to some other pieces of
gear to provide the desired function. For example, in order to de-ess,
the RNC's detector (also referred to as the "sidechain") is connected
to an equalizer. By having an equalizer in the detector, we can tell
the RNC which frequencies we want it to compress more than others.
Thus, for de-essing, we would accentuate (via the EQ's settings) the
frequencies associated with sibilance (anywhere from 5kHz to 12kHz)
while de-emphasizing all other frequencies. This would cause the RNC to
compress mostly the sibilant signals and leaving the other parts of the
signal mostly uncompressed.
The RNC's sidechain access may also let the RNC
"duck" two signals. What's "ducking"? It's the volume reduction of
music in the presence of another signal (usually a vocal narration). By
connecting the voice-over signal to the sidechain (with the main/music
channel hooked up to the RNC normally) and adjusting the RNC's front
panel controls properly, the music will be "potted down" (i.e., reduced
in volume) when the narrator is speaking.
How do I use the sidechain function
on the RNC?
De-Essing with the RNC
Using the sidechain function is merely a matter of connecting the
appropriate device via the appropriate adapter to the sidechain
connector. For example, to use the RNC as a stereo de-esser, you would
connect the RNC up as shown below.
In this application, a TRS
1/4" to (2) 1/4" mono phone plug adapter is used to get the RNC's
sidechain signal out of the RNC sidechain jack to an external equalizer
and back from the equalizer into the RNC. Once we insert a plug into
the sidechain jack, the sidechain signal is interrupted and, if we want
the RNC to do anything, we must return the signal back into the
sidechain jack. The output of the sidechain is sent on the "TIP" of the
sidechain connector while the returned signal is connected via the
"RING" part of the connector.
"Ducking" with the RNC
This application is similar to de-essing except that we're only
concerned with getting the signal we wish to "duck" with (we'll call
this the "duckor" and the signal we turning down, the "duckee") into
the sidechain (so that it will control the gain of the VCA). In this
case, we don't care if there's a sidechain signal coming out of the
RNC's sidechain jack (see below).