Radial Engineering MC3 User's Guide

®

True to the Music

™

MC3

Studio Monitor Controller

User Guide

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

www.radialeng.com

Radial® MC3™ User Guide

Table of Contents Page

Overview ...........................................................................1

Front panel features ..........................................................2

Rear and top panel features .............................................3

Balanced vs unbalanced ...................................................4

Connecting the MC3 .........................................................5

Using the level adjustment trims .......................................6

Setting up a subwoofer .....................................................7

Using the DIM control .......................................................7

Headphones ......................................................................8

Specications ....................................................................9

Block diagram ...................................................................9

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

Congratulations and thank you for purchasing the Radial
MC3 Studio Monitor Controller. The MC3 is an innovative
tool designed to make managing audio signals easy in
the studio while adding the convenience of an on-board

headphone amplier.

Even though the MC3 is super simple to use, as with any
new product, the best way to get to know the MC3 is by
taking a few minutes to read the manual and familiarize
yourself with the many features that are built-in before you
begin connecting things together. This could save you time.

If by chance you nd yourself seeking an answer to a

question, take a few minutes to log onto the Radial website
and visit the MC3 FAQ page. This is where we post the
latest information, updates and of course other questions

that may be similar in nature. If you do not nd an answer,

feel free to write us an email at [e-mail] and
we will do our very best to get back to you promptly.

Now get ready to mix with greater condence and control

than ever before!

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OVERVIEW

The Radial MC3 is a studio monitor selector that enables you to switch
between two sets of powered loudspeakers. This lets you compare how
your mix will translate on different monitors which in turn will help deliver
more convincing mixes to the audience.

Because most folks today listen to music with an iPod® using ear buds or
some other type of headphones, the MC3 features a built-in headphone

amplier. This makes it easy to audition your mixes using different

headphones and monitors.

Looking at the block diagram from left to right, the MC3 begins with stereo
source inputs. At the other end are the stereo outputs for monitors-A and
B, which are turned on or off using the front panel controls. The stereo
output levels can be trimmed to match for smooth switching between
different monitors without jumps in the listening level. The ‘large’ master
level control makes it easy to adjust the overall volume using a single
knob. Note that the master volume control sets the output going to all
speakers and headphones.

Using the MC3 is merely a matter of turning on the speakers you want,
adjusting the level and listening. All of the extra cool features in between
are icing on the cake!

INPUT

LEFT

RIGHT

FRONT

FRONT

3.5mm

HEADPHONE

AUX

SOURCE

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MASTER

LEVEL

JACKS

DIM &
MONO

HEAD

PHONES

LEFT

RIGHT

RIGHT

MONITOR-A

OUTPUT

LEFT

MONITOR-B

OUTPUT

SUBWOOFER

OUTPUT

OUT-A

TRIM

OUT-B

TRIM

SUB OUT

TRIM

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MC3 Monitor Controller

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FRONT PANEL FEATURES

1. DIM: When engaged, the DIM toggle switch temporarily reduces the
playback level in the studio without having to adjust the MASTER
level control. The DIM level is set using the top panel LEVEL
ADJUSTMENT control.

2. MONO: Sums the left and right inputs to test for mono-compatibility
and phase problems.

3. SUB: Separate on/off toggle switch lets you activate the subwoofer.

4. MASTER: Master level control used to set the overall output level
going to the monitors, subwoofer and AUX outputs.

5. MONITOR SELECT: Toggle switch activates the A and B monitor
outputs. Separate LED indicators illuminate when outputs are active.

6. HEADPHONE CONTROLS: Level control and on/off switch used to
set the level for the front panel headphone jacks and the rear panel
AUX output.

7. 3.5MM JACK: Stereo headphone jack for ear-bud style headphones.

8. ¼” JACKS: Dual stereo headphone jacks let you share the mix with
the producer when listening to playback or for overdubbing.

9. BOOKEND DESIGN: Creates protective zone around the controls
and connectors.

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MC3 Monitor Controller

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REAR PANEL FEATURES

10. CABLE CLAMP: Used to secure the power supply cable and prevent
accidental power disconnection.

11. POWER: Connection for a Radial 15VDC 400mA power supply.

12. AUX: Unbalanced ¼” TRS stereo auxiliary output controlled by the
headphone level. Used to drive an auxiliary audio system like a studio

headphone amplier.

13. SUB: Unbalanced ¼” TS mono output used to feed a subwoofer.
The output level may be trimmed using the top panel LEVEL
ADJUSTMENT controls to match the level of other monitor speakers.

14. MONITORS OUT-A & OUT-B: Balanced/unbalanced ¼” TRS outputs
used to feed active monitor speakers. The level of each stereo output
may be trimmed using the top panel LEVEL ADJUSTMENT controls
to balance the level between monitor speakers.

15. SOURCE INPUTS: Balanced/unbalanced ¼” TRS inputs receive the
stereo signal from your recording system or mixing console.

16. BOTTOM PAD: A full pad covers the underside, keeps the MC3 in
one place and won’t scratch your mixing console.

TOP PANEL FEATURES

17. LEVEL ADJUSTMENT: Separate set & forget trim controls on the
top panel make it easy to adjust A and B monitor levels for optimal
balance between different monitors.

18. SUB WOOFER: Level adjustment and 180º PHASE switch for the
subwoofer output. The phase control is used to reverse the polarity
of the subwoofer to counter the effect of room modes.

17 18

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MC3 Monitor Controller

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A

B B

A

S

RING

TIP

SLEEVE

RING

TIP

SLEEVE

SHIELD

RING

1 2

3

TIP

SLEEVE

RING

TIP

SLEEVE

RING

TIP

SLEEVE

SHIELD

SHIELD

RING

1 2

3

TIP

SLEEVE

RING

TIP

SLEEVE

RING

TIP

SLEEVE

SHIELD

SHIELD

SHIELD

1 2

3

TIP

SLEEVE

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TYPICAL MC3 SETUP

The MC3 Monitor Controller is typically connected to the output of your
mixing console, digital audio interface or laptop computer represented as
a reel-to-reel machine in the diagram. The outputs of the MC3 connect two
pairs of stereo monitors, a subwoofer and up to four pairs of headphones.

BALANCED VS UNBALANCED

The MC3 can be used with either balanced or unbalanced signals.
Because the main stereo signal path through the MC3 is passive, like a
‘straight-wire’, you should not mix balanced and unbalanced connections.
Doing so will ultimately ‘un-balance’ the signal through the MC3. If this is
done, you may encounter crosstalk or bleed. For proper performance,

always maintain either a balanced or unbalanced signal ow through

the MC3 by using appropriate cables for your equipment. Most

mixers, workstations and near-eld monitors can work either balanced or

unbalanced so this should not pose a problem when used with the proper
interface cables. The diagram below shows various types of balanced
and unbalanced audio cables.

Balanced TRS Source

Balanced XLR Source

Balanced XLR Source

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1 2

1 2

Balanced ¼” TRS ~ Balanced ¼” TRS

TIP

RING

SLEEVE

SHIELD

Balanced XLR ~ Balanced ¼” TRS

3

SHIELD

Unbalanced XLR ~ Unbalanced ¼” TS

3

SLEEVE

SHIELD

Unbalanced ¼” TS ~ Unbalanced ¼” TS

TIP

SHIELD

4

TIP

RING

SLEEVE

Balanced TRS Destination

TIP

RING

SLEEVE

Balanced TRS Destination

TIP

SLEEVE

Unbalanced ¼” TS Destination

TIP

SLEEVE

Unbalanced ¼” TS DestinationUnbalanced ¼” TS Source

MC3 Monitor Controller

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CONNECTING THE MC3

Before making any connections always ensure levels are turned down or
equipment is turned off. This will help avoid turn-on transients that could
harm sensitive components like tweeters. It is also a good practice to test

signal ow at a low volume before turning things up. There is no power

switch on the MC3. As soon as you plug in the power supply it will turn on.

The SOURCE INPUT and MONITORS-A and B output connection jacks
are balanced ¼” TRS (Tip Ring Sleeve) connectors that follow the AES
convention with tip positive (+), ring negative (-), and sleeve ground.
When used in unbalanced mode, the tip is positive and the sleeve shares
the negative and ground. This convention is maintained throughout.

Balanced TRS ¼” Phone Unbalanced TS ¼” Phone

Ring (-)

Ground

Ground

Ring (-)

Tip (+)

Tip (+)

Connect the stereo output of your recording system to the ¼” SOURCE
INPUT connectors on the MC3. If your source is balanced, use ¼” TRS
cables to connect. If your source is unbalanced, use ¼” TS cables to connect.

Connect the stereo OUT-A to your main monitors and OUT-B to your
second set of monitors. If your monitors are balanced, use ¼” TRS cables
to connect. If your monitors are unbalanced, use ¼” TS cables to connect.

Turn the A and B outputs on or off using the front
panel selectors. The LED indicators will illuminate
when the output is active. Both stereo outputs can
be active at the same time.

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MC3 Monitor Controller

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SETTING THE TRIM CONTROLS

The MC3 top panel is congured with a series of recessed trim controls.
These set & forget trim controls are used to ne tune the output level going

to each component so that when you switch from one set of monitors to
the other, they play back at relatively similar levels. Although most active
monitors are equipped with level controls, getting to them while listening

is difcult. You have to reach around the back to make the adjustments,
go back to the engineer’s seat, listen and then ne tune again which can

take forever. With the MC3 you adjust the level while sitting in your chair!

Easy and efcient!

Except for the active headphone and subwoofer outputs, the MC3 is a
passive device. This means it does not contain any active circuitry in the
stereo signal path to your monitors and therefore does not add any gain.
The MON-A and B LEVEL ADJUSTMENT controls will actually reduce
the level going to your active monitors. The overall system gain can
easily be made up by increasing the output from your recording system
or increasing the sensitivity on your active monitors.

1. Start by setting the gain on your monitors to
their nominal level setting. This is usually

identied as 0dB.

2. Set the recessed LEVEL ADJUSTMENT
controls on the MC3 top panel to the full­clockwise position using a screwdriver or guitar
pick.

3. Before you hit play, make sure the master
volume is turned all the way down.

4. Turn on monitor output-A using the MONITOR
SELECTOR switch. The output-A LED indicator
will illuminate.

5. Hit play on your recording system. Slowly

increase the MASTER level on the MC3. You

should hear sound from monitor-A.

6. Turn off monitor-A and turn on monitor-B. Try
going back and forth a few times to hear the
relative volume between the two sets.

7. You can now set the trim controls to balance

the level between your two monitor pairs.

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MC3 Monitor Controller

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CONNECTING A SUBWOOFER

You can also connect a subwoofer to the MC3. The SUB output on the MC3

is actively summed to mono so that the stereo input from your recorder

sends both the left and right bass channels to the subwoofer. You would of

course adjust the sub’s crossover frequency to suit. Connecting the MC3 to
your subwoofer is done using an unbalanced ¼” cable. This will not affect the
balanced monitor-A and B connections. Turning on the subwoofer is done by
depressing the SUB toggle switch on the front panel. The output level may
be adjusted using the top mounted SUB WOOFER trim control. Again, you
should set the relative level so that it sounds balanced when played with
your monitors.

On the top panel and next to the SUB WOOFER LEVEL control is a PHASE
switch. This changes the electrical polarity and inverts the signal going to
the subwoofer. Depending on where you are sitting in the room, this can
have a very dramatic effect on what is known as room modes. Room modes
are basically places in the room where two sound waves collide. When the
two waves are at the same frequency and in-phase, they will amplify each
other. This can form hot spots where certain bass frequencies are louder
than others. When two out-of-phase sound waves collide, they will cancel
each other out and create a null spot in the room. This can leave the bass
sounding thin.

Try moving your subwoofer around the room following the manufacturer’s
recommendation and then try reversing the phase of the SUB output to

see how it affects the sound. You will quickly come to realize that speaker
placement is an imperfect science and that once you nd a comfortable

balance you will likely leave the monitors alone. Getting used to how your
mixes translate to other playback systems takes some time. This is normal.

USING THE DIM CONTROL

A cool feature built into the MC3 is the DIM control. This lets you reduce the
level going to your monitors and subs without affecting the MASTER level
settings. For instance, if you are working on a mix and someone comes in
to the studio to discuss something or your cell phone starts ringing, you can
temporarily lower the volume of the monitors and then instantly go back to
the settings you had before the interruption.

As with the monitors and sub outputs, you can set the DIM attenuation
level using the set & forget DIM LEVEL ADJUSTMENT control on the top
panel. The attenuated level is usually set quite low so that you can easily
communicate over the playback volume. The DIM is sometimes used by
engineers who like to mix at low levels to reduce ear fatigue. Being able to
precisely set the DIM volume makes it easy to go back to familiar listening
levels with a push of a button.

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MC3 Monitor Controller

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HEADPHONES

The MC3 is also equipped with a built-in stereo headphone amplier. The
headphone amplier taps the feed after the MASTER level control and

sends it to the front panel headphone jacks and the rear panel ¼” AUX
output. There are two standard ¼” TRS stereo headphone outputs for
studio headphones and a 3.5mm (1/8”) TRS stereo out for ear buds.

The headphone amp also drives the rear panel AUX output. This active
output is an unbalanced stereo ¼” TRS output that is set using the
headphone level control. The AUX output can be used to drive a fourth
set of headphones or as a line-level output to feed additional equipment.

Be Careful: The output of the headphone amp is very powerful. Always
ensure the headphone level is turned down (fully counter-clockwise)
before auditioning music through headphones. This will not only save
your ears, but save the ears of your client! Slowly increase the headphone
volume control until you reach a comfortable listening level.

Headphone Safety Warning

Caution: Very Loud Amplier

As with all products capable of producing high Sound Pressure Levels (SPL)
users must be very careful to avoid the hearing damage that may occur from
prolonged exposure. This is particularly important as it applies to headphones.
Prolonged listening at high SPLs will eventually cause tinnitus and can lead
to partial or complete loss of hearing. Please be aware of the recommended
exposure limits within your legal jurisdiction and follow them very closely. The
user agrees that Radial Engineering Ltd. remains harmless from any health
effects resulting from the use of this product and the user clearly understands
that he or she is entirely responsible for the safe and proper use of this
product. Please consult the Radial Limited Warranty for further details.

MIXING IT UP

Top studio engineers tend to work in rooms they are familiar with. They
know how these rooms sound and instinctively know how their mixes
will translate to other playback systems. Switching speakers helps you
develop this instinctive sense by allowing you to compare how your mix
translates from one set of monitors to another.

Once you are satised with your mix on various monitor speakers you

will want to try listening with a subwoofer as well as through headphones.
Keep in mind that many songs today are downloaded for iPods and
personal music players and it is essential that your mixes also translate
well to ear bud style headphones.

TESTING FOR MONO

When recording and mixing, listening in mono can be your best friend.
The MC3 is equipped with a front panel MONO switch that sums the left
and right channels together when depressed. This is used to check if two
microphones are in phase, test stereo signals for mono compatibility, and
of course help you determine if your mix will hold up when played on AM
radio. Simply depress the MONO switch and listen. Phase cancellation in
the bass range is the most noticeable and will sound thin if out of phase.

Radial Engineering Ltd.

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MC3 Monitor Controller

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SPECIFICATIONS*

Radial MC3 Monitor Control

Circuit type: ......................................... Passive stereo with active headphones and subwoofer outputs

Number of channels: .......................... 2.1 (Stereo with subwoofer output)

Frequency response: .......................... 0Hz ~ 20KHz (-1dB @ 20kHz)

Dynamic range: .................................. 114dB

Noise: ................................................. -108dBu (Monitor A and B outputs); -95dBu (Subwoofer output)

THD+N: .............................................. <0.001% @1kHz (0dBu output, 100k load)

Intermodulation distortion: .................. >0.001% 0dBu output

Input impedance: ................................ 4.4K Minimum Balanced; 2.2K Minimum Unbalanced

Output impedance: ............................. Varies with level adjustment

Headphone max output: ..................... +12dBu (100k Load)

Features

Dim attenuation: ................................. -2dB to -72dB

Mono: .................................................. Sums left & right sources to mono

Sub: .................................................... Activates the subwoofer output

Source input: ...................................... Left & right balanced/unbalanced ¼” TRS

Monitors output: .................................. Left & right balanced/unbalanced ¼” TRS

Aux output: ......................................... Stereo unbalanced ¼” TRS

Sub output: ......................................... Mono unbalanced ¼” TS

General

Construction: ..................................... 14 gauge steel chassis & outer shell

Finish: ................................................. Baked enamel

Size: (W x H x D) ............................... 148 x 48 x 115mm (5.8” x 1.88” x 4.5”)

Weight: .............................................. 0.96 kg (2.1 lbs)

Power: ............................................... 15VDC 400mA power adapter (center pin positive)

Warranty: ........................................... Radial 3-year, transferable

BLOCK DIAGRAM*

LEFT

MASTER

LEVEL

RIGHT

SOURCE

INPUT

FRONT

HP

FRONT

HP

FRONT

3.5MM

AUX ON

REAR PANEL

* Subject to change without notice.

Radial Engineering Ltd.

HEAD

PHONE

LEVEL

NORMAL

DIM

LEVEL

MONO

SWITCH

DIM

9

OUT-A

LEVEL

ON

OFF

OUT-B
LEVEL

ON

OFF

SUB

LEVEL

ON

OFF

MC3 Monitor Controller

LEFT

RIGHT

MONITOR

OUT-A

LEFT

RIGHT

MONITOR

OUT-B

SUB
OUT

PHASE

180º

THREE YEAR TRANSFERABLE LIMITED WARRANTY

RADIAL ENGINEERING LTD. (“Radial”) warrants this product to be free from defects in
material and workmanship and will remedy any such defects free of charge according
to the terms of this warranty. Radial will repair or replace (at its option) any defective

component(s) of this product (excluding nish and wear and tear on components under

normal use) for a period of three (3) years from the original date of purchase. In the event
that a particular product is no longer available, Radial reserves the right to replace the
product with a similar product of equal or greater value. In the unlikely event that a defect
is uncovered, please call 604-942-1001 or email [e-mail] to obtain a RA

number (Return Authorization number) before the 3 year warranty period expires. The

product must be returned prepaid in the original shipping container (or equivalent) to
Radial or to an authorized Radial repair centre and you must assume the risk of loss or
damage. A copy of the original invoice showing date of purchase and the dealer name
must accompany any request for work to be performed under this limited and transferable
warranty. This warranty shall not apply if the product has been damaged due to abuse,

misuse, misapplication, accident or as a result of service or modication by any other than

an authorized Radial repair center.

THERE ARE NO EXPRESSED WARRANTIES OTHER THAN THOSE ON THE FACE
HEREOF AND DESCRIBED ABOVE. NO WARRANTIES WHETHER EXPRESSED
OR IMPLIED, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE SHALL EXTEND
BEYOND THE RESPECTIVE WARRANTY PERIOD DESCRIBED ABOVE OF THREE
YEARS. RADIAL SHALL NOT BE RESPONSIBLE OR LIABLE FOR ANY SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSS ARISING FROM THE USE
OF THIS PRODUCT. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND

YOU MAY ALSO HAVE OTHER RIGHTS, WHICH MAY VARY DEPENDING ON WHERE
YOU LIVE AND WHERE THE PRODUCT WAS PURCHASED.

To meet the requirements of California Proposition 65, it is our responsibility to inform you of the following:

WARNING: This product contains chemicals known to the State of California to cause
cancer, birth defects or other reproductive harm.

Please take proper care when handling and consult local government regulations before discarding.

®

True to the Music

www.radialeng.com

Radial Engineering Ltd.
1588 Kebet Way, Port Coquitlam, British Columbia, V3C 5M5

Tel: [phone] • Fax: [phone] • Email: [e-mail]

Radial® MC3™ User Guide - Part #: R870 1230 00 / 03-2017 - v2
Copyright 2017 Radial Engineering Ltd. All rights reserved.

Specications and appearances subject to change without notice.