FMR RNC Compressor FAQ - Frequently Asked Questions
Here's a collection of frequently asked
questions regarding the RNC.
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 of balanced?
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.
PROBLEMS
Why does the RNC distort my bass
guitar?
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
breathing?
There are several things you can do:
- Switch into SuperNice mode
- Reduce the total gain reduction amount
- Decrease the compression ratio
- Increase the attack time
- Increase 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).
COMPRESSOR
FEATURES/DETAILS
Is the RNC a peak, average or RMS-sensing
compressor?
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
soft-knee compression?
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...)
HOOKING IT UP
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 inserts?
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 not careful.
Connecting the RNC
to unbalanced equipment
This connection configuration is the most
straight-ahead.
Connecting the RNC to
balanced (XLR) equipment
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:
| RNC 1/4" Plug
| XLR Signal/Pin #
|
| Tip
| HOT (pin 2)
|
| Sleeve
| COLD (pin 3)
|
| Sleeve
| Ground
|
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 Inserts
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 bus?
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).
SIDECHAIN
What's the RNC's sidechain
function for?
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).
