Radial Engineering Komit User's Guide

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KOMIT

Compressor

500 Series Module

500

True to the Music

User Guide

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www.radialeng.com

Radial Engineering Ltd.
1588 Kebet Way, Port Coquitlam
British Columbia, Canada, V3C 5M5
tel: [phone] • fax: [phone]
email: [e-mail]

True to the Music

www.radialeng.com

Radial® Komit™ 500 User Guide

Table of Contents ........................................................Page

Feature Set .................................................................... 1

Overview ........................................................................ 2

Getting Started ............................................................... 7

Using The Compressor .................................................. 8

Using The Limiter ........................................................... 9

Example Applications ....................................................10

Specifi cations ................................................................12

Block Diagram ...............................................................13

Warranty ........................................................... Back cover

Congratulations and thank you for purchasing the Radial Komit 500 module. The Komit
is a unique compressor-limiter that is designed to produce effective musical results without
the complexity normally associated with dynamic processors. In other words, the Komit is
all about getting there quickly whether you are looking for simple clean compression or wish
to create dramatic effects.

This manual describes installing and operating your Komit in the Radial Workhorse or other
500 series module power racks. To take full advantage of the unique features that have been
incorporated into the Komit, please read through this manual before using it. This will give you
a broader sense of its capabilities. If you have questions that are not covered in this manual,
please visit the FAQ section on our website. This is where we post answers to questions from
users. If you cannot fi nd the answer to your question please feel free to send an email to:
[e-mail] and we will do our very best to respond as quickly as possible.

The Radial Komit lets you elegantly control with realism or squash it beyond recognition!

WARNING NOTICE TO USER!

Although preventative safety measures have been designed into Radial 500 series
products we strictly advise against hot-swapping modules or plugging and
unplugging them when the Workhorse or other 500 series rack is powered on. Hot
swapping can cause connection sparks at the card-edge connector that could send
damaging transients to other equipment. This also greatly reduces the life span of the
contacts. Damage due to hot swapping is not covered under warranty. There are no
user serviceable parts inside.

True to the Music

INPUT

OMNIPORT

FEED

LINK

1

OFF

OFF

CARD SLOT 1

OUTPUT

OUTPUT

INPUT

FEATURE SET

1. DUAL BALLISTIC LED METER - Divided in half with
gain reduction on the left and output on the right. Easy
to read and fast, it provides instant visual monitoring
of signal status.

2. LIMITER - 12 position dial lets you choose between
brick wall limiting, bypass and ‘old school diode-bridge
clipping limiter’ circuit. Ten graduated settings that
range from slight clipping to over the top distortion.

3. BW (LIMITER DIAL) - Doubles the compression ratio
(1:1; 6:1; 20:1) and bypasses the clipping limiter.
Turns the Komit into a set & forget brick wall limiter (at
20:1 compressor setting) for digital recording.

4. FAST / MEDIUM / SLOW - Three speed settings with
feed-forward auto-detection make it easy to address
the attack and release time constants. Slow for vocals,
medium for instruments and fast for percussion.

5. COMPRESSOR RATIO - State of the art VCA
FlexKnee™ compression circuit delivers dynamic
control from slight to extreme with up to a 10:1
compression ratio. Single RATIO control says it all!

6. SYNC - Lets you control two Komits sharing the same
time constant. Set up in a master-slave confi guration
for optimal stereo dynamic coupling. Sync ‘on’ turns
unit into slave.

7. INPUT - Lets you toggle the input threshold between
+4dB and -10dB to optimize signal input range making
the Komit easy to interface with all types of program
material.

8. GAIN - Used as gain make-up when signals are
compressed to set the output level. Variable with up
to +22dBu of gain, is also used to drive the limiter for
extra character.

9. ON - Bypass switch lets you quickly compare the
original pre-compressed signal to the settings you
have selected on the Komit. Push in to turn on!

10. LINK - When used with the Workhorse, the stereo link
switch lets you combine two Komits together following
the same time constant. Also active on standard 500
series racks using the pin-6 card edge terminal.

11. OMNIPORT - Designated as a key input to allow
external control over the compressor side chain.
Available only when used with the Workhorse.

Radial Engineering Ltd.

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Radial Workhorse

Rear Panel

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Komit 500 Module

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True to the Music

OVERVIEW

The Radial Komit is a combination compressor-limiter designed for ‘one knob’ operation. This
eliminates the guess work that often makes dynamic processing a challenge. But don’t let the
diminutive front panel make you think that the Komit is ‘limited’… there are tons of features
just raring to get used!

The Komit is made up of two major building blocks: the compressor and the limiter. The
Flex-Knee™ compression circuit is a voltage controlled amplifi er (VCA) while the limiter is
a unique clipping circuit designed to simulate the sound created by old school diode bridge
inputs from the early days of radio. In between is a gain make-up control that lets you adjust
the output to compensate or drive the clipping limiter to create various effects.

BYPASS

INPUT

VOLTAGE CONTROLLED

AMPLIFIER

OUTPUT GAIN STAGE

0dB ~ +20dB

VARIABLE LIMITING

CLIPPER

OUTPUT

Getting great sounding compression is often described as one of the most diffi cult challenges
in audio. This is attributed to the complex balance involved in setting the input level, threshold,
compression ratio, attack time, release and gain make-up. Too much or too little of any one
parameter and the track ends up sounding bad. With the Komit, many of these controls
have been purposely omitted. Instead, each control has been carefully crafted to achieve
great results with a limited amount of fi ddling and knob twisting. The following describes
compression and how we managed to develop the Komit’s ‘one-knob’ control.

What Is Compression Anyway?

In simple terms, a compressor is an automatic level controlling device. In the early days
before compressors, the audio engineer basically had to adjust the volume manually in order
to keep the dynamic range under control. Back then, the dynamic range was limited to around
60dB and with big band orchestras generating peaks as high as 100dB, keeping the levels
under control was an art to be sure. Compressors changed the way music was recorded by
automatically keeping the signal under control. With today’s digital technology, we are now
able to record with as much as 120dB of dynamic range. But this poses a new problem: when
musical passages are low, we turn up the volume to hear the music above the ambient noise.
And then when thunder strikes, the resulting transients can be deafening.

Compressors are used to limit the transients by attempting to keep the program material
within a given range. For example, the shaded area in the image below depicts the average
program level. When the program level exceeds the average (the dashed line depicts the
threshold), compression is applied.

110dB -

100dB -

90dB -

80dB -

Radial Engineering Ltd.

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Komit 500 Module

True to the Music

Voltage Controlled Amplifi ers

A VCA or voltage controlled amplifi er is exactly that… an amplifi er whose level is controlled
by an external voltage. This control voltage uses what is known as an RMS detector that
reads the program material. When a peak arrives that is above the acceptable threshold, the
amplifi er’s output is reduced automatically. The amount of reduction is set by the engineer
using the compression ratio. The ratio can be set for slight compression to extreme whereby
with every decibel (dB) that comes in, only a certain percentage will be allowed to pass.

SLIGHT MODERATE SIGNIFICANT HEAVY BRICK WALL

1.2 : 1 2 : 1 5 : 1 10 : 1 20 : 1

1.2dB in : 1dB out 2dB in : 1dB out 5dB in :1dB out 10dB in : 1dB out 20dB in :1dB out

83% allowed to pass 50% allowed to pass 20% allowed to pass 10% allowed to pass 4% allowed to pass

Using the example above, if the ratio is set at 2:1 and there is a 10dB peak, the VCA will
only allow 5dB to pass. When the compression ratio is pushed above 10:1, the compressor
is generally considered to be a limiter. When the ratio is above 20:1 it is often referred to as
a ‘brick wall’. In this case, for every 10dB that is applied, barely ½ dB will pass. A brick wall
limiter is used to keep the signal out of the red. As a rule, the less compression you apply, the
more natural the program material will sound.

110dB -

100dB -

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90dB -

80dB -

Controlling The VCA

The Komit’s VCA employs what is known as a feed-forward detection circuit. In other words,
it looks at the incoming signal before it arrives and adjusts itself accordingly to control the
peak. When it ‘sees’ a peak that exceeds the threshold (dashed line), depending on how the
compression ratio has been set, the VCA will reduce the output to compensate.

Radial Engineering Ltd.

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Komit 500 Module