Radial Engineering Decoder User manual

www.radialeng.com
True to the Music
®
User Guide
Decoder™
Mid/Side Matrix
Radial Engineering Ltd.
1588 Kebet Way, Port Coquitlam
British Columbia, Canada, V3C 5M5
Tel: [phone] • Fax: [phone]
Email: [email protected]

Table of Contents Page
Front Panel Features ........................................................... 1
Rear and Top Panel Features .............................................. 2
Overview .............................................................................. 3
Making Connections ............................................................ 4
MID/SIDE Recording............................................................ 5
Three Cardioid Microphones................................................ 6
MID/SIDE Reamping............................................................ 7
Using as a Mic Preamp........................................................ 8
Mixer Options....................................................................... 9
HPF, 48V and Polarity Switch’s.......................................... 10
Block Diagram.................................................................... 11
Specications..................................................................... 12
Warranty............................................................... Back cover
Congratulations on your purchase of the Radial Decoder
Mid/Side Matrix. The Decoder is designed to make Mid/
Side tracking and Reamping fun and easy. This manual
covers the setup and operation of the Decoder in the studio
environment. Please take a few minutes to read through this
manual in order to familiarize yourself with the Decoder’s
features and applications. Inside you will nd important
safety features along with tips on how to get the most out of
your Decoder.
Should you have any questions on an application not covered
in this manual, we invite you to log onto the radial website at
radialeng.com to check the Decoder’s FAQ section for the
latest updates. If you still do not nd what you are looking for,
feel free to send us an email at [email protected].
Now have fun creating Mid/Side stereo recordings quickly
and more easily than ever before!
Radial®Decoder™User Guide

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Radial Engineering Ltd. Decoder Mid/Side Matrix
True to the Music
®
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1 2 8 93 74 65 10 11 12
FRONT PANEL FEATURES
1. 1: Turns preamp 1 (MID microphone) on and off
2. HPF: High pass lter to reduce low frequency rumble
3. 48V: Input-1 phantom power switch is recessed to prevent
accidental turn-on which could damage certain mics
4. GAIN: Adjusts input level of mic/line input-1
5. 2a: Turns preamp 2a (SIDE microphone) on and off
6. GAIN: Adjusts input level of mic/line input-2a
7. 48V: Input-2a/2b phantom power switch
8. HPF: High pass lter for inputs-2a/2b
9. LINK: Duplicates, pans and reverses the phase of input-2a for
traditional M/S operation
10. 2b: Turns on the optional third preamp
11. GAIN: Adjusts input level of mic/line input-2b
12. 180°: Reverses the phase of input-2b when using with a third
microphone
13. FRONT LIP: Creates protective zone around switches and
controls to prevent unintentional changes and protect the Decoder
from damage when moving

True to the Music
®
Radial Engineering Ltd. Decoder Mid/Side Matrix
2
14 15 16 17
21
18 19 20
REAR PANEL FEATURES
21. INPUT LEVEL SELECTOR: Allows user to select mic or line level
on each channel. Switches are recessed to prevent accidental
changes while recording
14. CABLE CLAMP: Used to secure the power supply cable in mobile
installations
15. POWER: 15VDC power connection for external power supply
16. RIGHT & LEFT OUTPUTS: Balanced +4dBu XLR stereo outputs
17. MIC 1 IN: Mic/line input for main ‘MID’ microphone or line source
18. INPUT-2a: Mic/line input for ‘SIDE’ microphone or line source
19. INPUT-2b: Mic/line input for optional third microphone or line source
20. NO SLIP PAD: A full pad covers the underside, keeps the Decoder
in one place and won’t scratch your mixing console
TOP PANEL FEATURES

Radial Engineering Ltd. Decoder Mid/Side Matrix
True to the Music
®
3
WHAT IS MID/SIDE?
Mid/Side is a stereo microphone technique that has been around since
the 1930’s, and has been used on countless stereo recordings ever
since. The idea is that a cardioid or Omni-directional MID microphone is
aimed directly at the source to capture the direct sound, and a gure-8
SIDE microphone is pointed 90° off axis to capture the ambient energy.
The SIDE mic is then split into two separate channels, and the phase is
reversed on the second channel. While it all sounds very complicated,
reversing the phase of the copied signal simply allows the user to hear a
left and right stereo image as it is captured by the front and back of the
gure-8 microphone.
The result is a stereo image that can be manipulated by adjusting the
levels between the MID and SIDE microphones. Raising or lowering the
level of either will change the width of the stereo image, and the MID
microphone will act as a center channel, keeping the source focused and
present. The engineer can quickly tailor the balance between MID and
SIDE to create a stereo image that is perfect for their application.
M/S is also popular in broadcast as it allows for better mono compatibility
than any other stereo mic’ing technique. Because the SIDE channels
are out of phase with one another, they cancel one another out when
the mix is collapsed to mono. While other stereo mic’ing options tend
to disappear in mono mix downs, M/S allows the source microphone to
become more focused and present in the mix. The center is never lost!
OVERVIEW
The Decoder is a multi-channel microphone preamp and M/S stereo
matrix that allows the user to easily create M/S recordings without having
to congure a recording console. The Decoder can be used for traditional
M/S recording with two microphones, or with three microphones for a
unique approach. It can also be used to Reamp pre-recorded tracks
through its M/S matrix during mix-down.
+ =
CARDROID FIGURE-8
MID
SIDE
+ -

True to the Music
®
Radial Engineering Ltd. Decoder Mid/Side Matrix
4
MAKING CONNECTIONS
Before connecting, it is good practice to lower all levels or turn audio
systems off as this will prevent turn-on or plug-in transients from damaging
more sensitive components such as tweeters.
Begin by connecting the left and right XLR outputs jacks of the Decoder
to your audio interface or mixing console. Ensure that your inputs are
setup for +4dBu line level, and balanced cables are used throughout.
Attach the included 15VDC power supply. The Decoder does not have a
power switch, so it is always on when connected. As an extra protective
measure, the Decoder is equipped with a cable lock that eliminates the
risk of accidentally pulling out the power supply. Using a hex key, loosen
the clamp and pass the power cable through the loop. Then re-tighten.
The most common method if M/S recording is to combine a cardioid or
omni-directional microphone with a gure-8 mic. This is often used to
capture a wonderful stereo image of an acoustic guitar, solo violin or
ambient recording of a quartet.
MID/SIDE RECORDING
Cardioid
Figure-8

Radial Engineering Ltd. Decoder Mid/Side Matrix
True to the Music
®
Figure-8 Mic
Cardioid Mic
5
LINE
MIC
Link On
1. Setup microphones in the standard
M/S conguration. The MID cardioid
mic should be aimed at the source,
and the SIDE gure-8 directly
below it at 90° off-axis. Try to place
the capsules as close together as
possible to minimize phase issues.
2. Ensure recessed switches on the Decoder’s top panel are all set to ‘Mic’.
3. Connect the cardioid MID mic to input-1, and the SIDE mic to input-2a
on the back of the Decoder.
4. Press LINK button on Decoder’s front panel. This sends input-2a
(gure-8) to the third channel and lets you use the gain control to
adjust the stereo eld.
5. Apply phantom power on both channels if required. Be careful to make
sure audio signals are turned off to avoid a loud pop when turning on
the phantom power. The 48V phantom power switch is recessed to
prevent accidental switching.
6. Start by bringing up the GAIN control of input-1 to an audible level on
your system.
7. Slowly start bringing up the GAIN controls of inputs-2a and 2b. You
will notice the stereo image widens and narrows as you bring up the
SIDE’s.
8. Experiment by changing the level of MID mic as well. Don’t forget to
watch the meters on your recorder… it is easy to get carried away!
ONE CARDIOID MICROPHONE, ONE FIGURE-8 MIC

True to the Music
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Radial Engineering Ltd. Decoder Mid/Side Matrix
6
THREE CARDIOID MICROPHONES
The Decoder is equipped with a third microphone input. This allows the
user to substitute the gure-8 mic with a pair of cardioid microphones to
simulate the same effect. Bringing the mic’s as close together as possible
will minimize phase issues.
1. Setup the MID microphone by aiming it directly at the source. Connect
this mic to input-1 on the Decoder.
2. Setup your left SIDE microphone by placing it directly below and 90°
off axis from the MID mic. Connect this mic to input-2a on the Decoder.
3. Setup your right SIDE microphone by aiming it directly opposite of your
side mic. Initially the goal is to replicate a gure-8 polar pattern, so
try and get the capsules as close together as possible. Side-address
microphones work great!
4. Engage the 180° phase reverse on input-2b (button IN).
5. Make sure the LINK button is set to the OUT position so that it does not
receive the signal from input-2a.
6. Apply phantom power on channels 1, 2a and 2b if required. Note that
the phantom ON switch for channels 2a and 2b are combined and
adjacent to the input 2a gain switch. The 48V phantom power switches
are recessed to prevent accidental switching.
7. Start by bringing up the GAIN control on input-1 to an audible level on
your system.
8. Slowly start bringing up the GAIN controls of inputs-2a and 2b.
9. Start experimenting with different placements of your SIDE mics.
Spacing mics far apart or even running stereo room mics through the
Decoder can lead to some interesting results!
180°Phase
Switch ON

Radial Engineering Ltd. Decoder Mid/Side Matrix
True to the Music
®
7
MID/SIDE REAMPING - OPERATING AT LINE LEVEL
The Decoder features top mounted switches that let you change the
input sensitivity from mic level to line level, thus allowing you to send pre-
recorded +4dB (nominal) M/S tracks from your workstation for Reamping.
This lets you apply M/S techniques to change the stereo image of a track
during mix-down.
From the output of your recorder, send the pre-recorded MID track to
the Decoder input-1 and the SIDE track to input-2a. If you are using two
SIDE sources, patch the second line into input-2b. Be sure that you are
monitoring the return channels from the Decoders outputs to hear the
processed stereo image.
1. Set input level selector switches on top panel to ‘LINE’ position (up).
2. Ensure that the GAIN controls are turned all the way down on the front
panel before proceeding.
3. Engage LINK button on the front panel if only two inputs are being used.
4. Engage 180° button on the front panel if all three inputs are being used
(link off).
5. Start playback on your recorder and slowly increase the GAIN on input-1.
6. Once the signal is audible, begin increasing the GAIN on inputs-2a
and 2b.
7. Change the stereo image by increasing or decreasing the relative
levels of all three inputs.
8. Experiment with Reamping different stereo recordings like overheads
or room mics… there are no rules! Have fun!