Radial Engineering MC3 User manual

True to the Music
www.radialeng.com
True to the Music
User Guide
MC3™
Studio Monitor Controller
www.radialeng.com
Radial Engineering Ltd.
1588 Kebet Way, Port Coquitlam
British Columbia, Canada, V3C 5M5
tel: [phone] • fax: [phone]
email: [email protected]

Radial®MC3™User Guide
Table of Contents ......................................................Page
Overview ........................................................................ 1
Feature set ..................................................................... 2
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 web site 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 [email protected] 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!

True to the Music
®
Radial Engineering Ltd. MC3 Monitor Controller
1
OVERVIEW
The Radial MC3 is a studio monitor selector that enables you to switch between two sets
of powered loudspeakers. This lets you to 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. These 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!
LEFT
RIGHT
SOURCE
INPUT
MONITOR-A
OUTPUT
MONITOR-B
OUTPUT
SUBWOOFER
OUTPUT
HEADPHONE
JACKS
AUX
3.5mm
FRONT
FRONT
LEFT
RIGHT
LEFT
RIGHT
MASTER
LEVEL
DIM &
MONO
HEAD
PHONES
OUT-A
TRIM
OUT-B
TRIM
SUB OUT
TRIM

Radial Engineering Ltd. MC3 Monitor Controller
True to the Music
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2
FRONT PANEL
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. BOTTOM PAD: A full pad covers the underside, keeps the MC3 in one place and won’t
scratch your mixing console.
10. BOOKEND DESIGN – Creates protective zone around the controls and connectors.
11. BAKED ENAMEL – Tough outer coat is designed to keep your MC3 looking good for
years.
FEATURE SET
1 953 72 111064 8

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Radial Engineering Ltd. MC3 Monitor Controller
3
REAR PANEL
12. SOURCE INPUTS – Balanced/unbalanced ¼” TRS inputs receive the stereo signal from
your recording system or mixing console.
13. CONFIG – Recessed toggle switch used to congure the monitor-A and B outputs for
balanced or unbalanced operation. Set the toggle switch to match the type of cables you
are using to connect the MC3 inputs and outputs.
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. 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.
16. 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.
17. POWER – Connection for a Radial 15VDC 400mA external power supply.
18. CABLE CLAMP – Used to secure the power supply cable and prevent accidental power
disconnection.
TOP PANEL
19. 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.
20. 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.
FEATURE SET
15 1317
19 20
1216 1418

Radial Engineering Ltd. MC3 Monitor Controller
True to the Music
®
4
TYPICAL MC3 SETUP
The MC3 Monitor Control 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.
A
B B
A
S
BALANCED VS UNBALANCED
The MC3 can be used in either balanced or unbalanced mode by setting the conguration
(CONFIG) switch on the rear panel to suit. 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

the appropriate setting. Most mixers, workstations and near-eld monitors can be used in
either mode, 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.
RING
1 2
3
TIP
SLEEVE
RING
TIP
SLEEVE
RING
TIP
SLEEVE SHIELD
SHIELD
SHIELD
SHIELD
1 2
3
TIP
SLEEVE
TIP
SLEEVE
TIP
SLEEVE
RING
1 2
3
TIP
SLEEVE
RING
TIP
SLEEVE
RING
TIP
SLEEVE SHIELD
SHIELD
SHIELD
SHIELD
1 2
3
TIP
SLEEVE
TIP
SLEEVE
TIP
SLEEVE
RING
1 2
3
TIP
SLEEVE
RING
TIP
SLEEVE
RING
TIP
SLEEVE SHIELD
SHIELD
SHIELD
SHIELD
1 2
3
TIP
SLEEVE
TIP
SLEEVE
TIP
SLEEVE
RING
1 2
3
TIP
SLEEVE
RING
TIP
SLEEVE
RING
TIP
SLEEVE SHIELD
SHIELD
SHIELD
SHIELD
1 2
3
TIP
SLEEVE
TIP
SLEEVE
TIP
SLEEVE
Balanced TRS Source
Balanced ¼” TRS ~ Balanced ¼” TRS
Balanced XLR Source
Balanced XLR ~ Balanced ¼” TRS
Unbalanced XLR ~ Unbalanced ¼” TS
Balanced XLR Source
Balanced TRS Destination
Balanced TRS Destination
Unbalanced ¼” TS Destination
Unbalanced ¼” TS DestinationUnbalanced ¼” TS Source
Unbalanced ¼” TS ~ Unbalanced ¼” TS

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Radial Engineering Ltd. MC3 Monitor Controller
5

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.
Ground
Tip (+)
Ground
Tip (+)
Ring (-) Ring (-)
Balanced TRS ¼” Phone Unbalanced TS ¼” Phone
Connect the stereo output of your recording system to the ¼” SOURCE INPUT connectors on
the MC3. Set the CONFIG switch to its appropriate setting for either balanced or unbalanced
operation depending on the type of cables you are using.
BAL/UNBAL CONFIG
Connect the stereo OUT-A to your main monitors and OUT-B to your second set of monitors.
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.

Radial Engineering Ltd. MC3 Monitor Controller
True to the Music
®
6

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 full-clockwise 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 monitors-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.

True to the Music
®
Radial Engineering Ltd. MC3 Monitor Controller
7

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 from 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.
A
B B
A
S
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.

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. So 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.

Radial Engineering Ltd. MC3 Monitor Controller
True to the Music
®

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.
 
 
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.

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 connected and listening 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.

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 compatability, and of course will 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.
8