SoundCraft ZL0439, Spirit SX Manual To Mixing

SOUNDCRAFT

HARMAN INTERNATIONAL INDUSTRIES LTD.
CRANBORNE HOUSE,
CRANBORNE ROAD,
POTTERS BAR,
HERTS,EN6 3JN,UK.
TEL: [phone]
FAX: [phone]
EMAIL: [e-mail]

SOUNDCRAFT USA

1449 DONELSON PIKE,
NASHVILLE TN 37217,USA
TEL: [phone]
FAX: [phone]
EMAIL: [e-mail]

www.soundcraft.com

Soundcraft reserves the right to improve or otherwise alter any information supplied in this
document or any other documentation supplied hereafter. E&OE 08/01

Part No. ZL0439

Soundcraft Registered Community Trade Mark / RTM No. 000557827

THE SOUNDCRAFT
GUIDE TO MIXING

SECTION 1: STARTING OUT

A What does a Mixer do? 3
B Guidelines in Choosing a Mixer. 3
C The Controls - A Description. 3

Mono Inputs, Stereo Inputs, Subgroups,
the Master Section.

D Signal Flow. 7

SECTION 2: CONNECTING
EQUIPMENT TO YOUR MIXER

A Input Devices. 8
B Equipment requiring Inputs and Outputs. 9
C Output Devices. 9

SECTION 3:
MIXING TECHNIQUES

A Choosing the Right Microphone; 10

Microphone types, Condenser, Dynamic,
Electret. Different Polar Patterns.

B Setting up a Basic Mix; 11

Setting the Gain, Balancing Fader Levels,
Balancing Output Levels.

C Using the Mixer’s EQ; 12

Fixed EQ. Using a sweep-mid equaliser.

D Using Effects Units; 13

The different types; Reverb, Delay, Echo,
Chorus & Flanging, Pitch Shifters.
Setting up an effects loop.
Pre and post fade auxiliaries.

E Using Signal Processors; 15

The difference between signal processors and effects;
Different types of signal processors; Graphic Equalisers,
Parametric Equalisers, Gates, Expanders,
Compressors/Limiters.
Setting up a processor.

F Creating a Foldback/Monitor Mix. 16

SECTION 4: PA MIXING

A Introduction, A Typical Live Performance; Microphones,

Cables and Connections, Connecting External Effects and
Processors, Setting Up, Ringing Out: Nulling Room
Acoustics, Setting the Mix, Avoiding Feedback. 17

B Larger Performances; Medium Venues,

Large Sized Venues. 20

C Recording Live. 22

SECTION 5:
OTHER APPLICATIONS

A Monitor mixing. 23
B Submixing. 24

SECTION 6: IN THE STUDIO

A Essentials and Ergonomics. 25
B Tape Machines and Recording media. 25
C The Console. 25
D Simple Multitrack Recording. 26
E Simple Multitrack Mixdown. 27
F Using a Dedicated In-Line Console. 28
G Recording Instruments and Voices; Vocals, Drums, Electric

Guitars, Acoustic Guitars, Bass Guitars, Keyboards. 28
H Planning a Session. 30
I Creating a Mix. 30
J Balancing the Mix. 30

SECTION 7:
WIRING UP & CONNECTORS

Balanced and Unbalanced Mic Inputs, Balanced and

Unbalanced Line Inputs. 31

Inserts, Ground Compensated Outputs, Impedance

Balanced Outputs. 31

SECTION 8: GLOSSARY

An A to Z to save your head! 32

CONTENTS

2

THE SOUNDCRAFT GUIDE TO MIXING – CONTENTS

STARTING OUT

A. What does a Mixer do?

No matter how sophisticated or expensive, all mixers carry
out the same basic function - to blend and control the
volume of a number of input signals, add effects and
processing where required and route the resulting mix to
the appropriate destination, which could be power
amplifiers, the tracks of a recording device - or both. A
mixer is the nerve centre of these sources, and therefore the
most vital part of your audio system.

B. Guidelines in

Choosing a Mixer

Audio mixers come in many different sizes and at all price
levels, so it’s little wonder that people are confused as to
what type is actually needed for the job in hand. However
there are several questions you can to ask yourself that will
help you narrow your search to the most appropriate
models.

• What am I going to be using the mixer for - i.e.
multitrack recording, live PA work or both?

• What is my budget?

• How many sound sources do I have? As a guideline your
mixer needs to have at least as many inputs as sound
sources. If you are likely to be buying more equipment in
the future you should budget for extra inputs.

• What particular mixer facilities must I have for my
application? i.e. plenty of EQ, auxiliaries, or Direct Outs
for recording.

• How portable does the mixer need to be?

• Will I be doing any location work where there won’t be
any mains power available?

• Have I read the Soundcraft Guide to Mixing from cover
to cover?

Once you can answer these questions satisfactorily you
should have a fairly accurate specification for the mixer you
need.

C. The Controls -

A Description

This is where we get into the nitty-gritty of
what controls and inputs/outputs you’ll find
on a typical mixer. For this example, we’ve
used a Spirit SX . If you are already

familiar with what the controls on a
standard mixer do, then it’s OK to skip to
section 2. If you find a term particularly

difficult, further explanation can be found
in the Glossary (Section 8).

MONO INPUTS

A Mic In

Use this "XLR" input to connect your
microphones or DI boxes.

For Mic Input Wiring Explanations see section 7.

B Line In

Use this connector for plugging in "Line
Level" instruments such as keyboards,
samplers or drum machines. It can also be
used to accept the returns from multitrack
tape machines and other recording media.
The Line Input is not designed for
microphones and although it may be used,
will not provide optimum performance with
them.

For Line Input wiring explanations see section 7.

C Insert Point

This is used to connect external signal
processors such as compressors or limiters
within the input module. The Insert Point

allows external
devices to be
placed within the
Input Path - see
Fig. 1.1.

See Section 2 and 3
for more detail on how to use processors, and
Section 7 for information on wiring.

SECTION 1: Starting Out

3

100

1515

12 12

99

66

33

0

–+

1515

12 12

99

66

33

0

–+

1515

12 12

99

66

33

0

–+

100

0

5

10

203040

50

-60dBu

55

44

33

22

11

0

DIR

LINE

INS

MIC

SENS

100Hz

MID

LF

100

100

HF

AUX

1

PRE

AUX

2

POST/

PRE

AUX

3

POST

PAN

10

5

0

5

10

15

20

30

∞

0N

MIX

SUB

PFL

8

A

B

C

FIG. 1.1

INSERT

MIC/LINE

EQ

PROCESSOR

- COMPRESSOR

- NOISE GATE

- LIMITER

- EXPANDER

D Direct Out

This allows you to send audio direct from
your channel out to a multitrack tape
recorder, or to an effects unit when the channel
requires its own special effect.

See sections 2 and 6 for more details on connections
and studio techniques.

E Gain Control (Input Sensitivity)

Sets how much of the signal from the
mic or line inputs is fed to the channel.

F HPF (High Pass Filter)

As the name suggests this switch cuts out the
very lowest frequencies of a sound whilst
allowing the higher frequencies to “Pass
Through”. It’s particularly useful in live
situations to reduce stage rumble or microphone
‘popping’, which can produce a muddy mix,
or to ‘clean-up’ male vocals and filter out low
frequency hum. Some manufacturers may
also use the term “low - cut” filter to describe
the HPF. See Fig. 1.2.

G EQ Section

Usually the most closely scrutinised part of
any mixer, the equaliser section allows you to
change the tone of the sound on each input.
An EQ is normally split into “bands”, which
control a range of frequencies, in a similar
fashion to the treble and bass tone controls on
your Hi-Fi. Indeed a simple “2 band” EQ is
little more than an input treble and bass control.
The more bands an EQ has the more
sophisticated it is. SX has a 3 band EQ, with a
separate control for the middle audio
frequencies. This control is also “swept” which
provides even more sophistication. Simply
described, a sweep EQ allows you to choose
the exact frequency to cut and boost, rather
than having it chosen for you, as on normal
“fixed” controls.

We will talk in more detail about EQ in section 3.

H Auxiliary Section

Typically, these controls have two functions: First, to
control the levels of effects such as reverb from external
effects units that have been added to the input signal, and
second to create separate musician’s "foldback" mixes in
the studio or on stage.

How to use auxiliaries, connecting them to external equipment
and other applications are described in section 3.

I Pan (Panoramic Control)

This determines the position of the signal within the
stereo mix image or may be used to route (send) the signal
to particular GROUP outputs as selected by the
ROUTING SWITCHES (see below).

J Solo (PFL and Solo in Place)

The PFL solo switch allows you to monitor an input
signal independently of any other instruments that have
been connected, which is useful for troubleshooting, or
setting an instrument’s Input Preamp Gain and EQ
setting.

Pre-Fade Listen (PFL) is a type of solo that allows you
to monitor your sound BEFORE THE FADER. In other
words when you move the input fader in PFL mode the
level will not change, nor will you hear any effects.
Because effects and volume are not a distraction, PFL solo
is very useful for setting proper input preamp levels.

Some Soundcraft mixers use SOLO IN PLACE, which
allows you to monitor signals after the fader in their true
stereo image, and with any effects that have been added.
This type of Solo is less good for level setting, but more
useful in mixdown situations for auditioning sounds.

See section 3 - Setting Gain, for more information on using PFL.

K Mute/Channel On-Off Switch

This turns the channel on or off and is useful for isolating
the channel when not in use or pre-setting channel levels
which may not be needed until later, ie: theatre scene­setting or support acts/performers.

L Fader

This determines the level of the input signal within the
mix and provides a visible indication of channel level.

M Routing

By selecting the routing switches the input signal is sent
to a choice of the mixer’s outputs - typically the main mix
outs or the group outputs. The switches are used in
conjunction with the PAN control to route the signal
proportionately to the left or the right side of the mix
or to odd/even groups/subs if PAN is turned fully left or
right.

SECTION 1: Starting Out

4

dB

20 100 1k

10k

Hz

60

+20
+15
+10

+5

0

-5

-10

-15

-20
500 5k

STAGE RUMBLE
MIC “POPPING”

-3

100

1515

12 12

99

66

33

0

–+

1515

12 12

99

66

33

0

–+

1515

12 12

99

66

33

0

–+

100

0

5

10

203040

50

-60dBu

55

44

33

22

11

0

DIR

LINE

INS

MIC

SENS

100Hz

MID

LF

100

100

HF

AUX

1

PRE

AUX

2

POST/

PRE

AUX

3

POST

PAN

10

5

0

5

10

15

20

30

∞

0N

MIX

SUB

PFL

8

100Hz

HPF

D

E
F

G

H

I

K

M

L

J

FIG. 1.2

FIG. 1.3

STEREO INPUTS

Guitar amps and mic’d sound sources only
provide you with mono signals. However
keyboards, samplers, drum machines and other
electronic media often provide true stereo
outputs with separate left and right signals.
Stereo Inputs on mixers simply allow you to
connect both of these signals individually and
control them from a single fader. Stereo inputs
tend to incorporate fewer facilities than mono
inputs as most keyboards are already equipped
with plenty of internal effects and tone control
options.

NB: Soundcraft jack stereo inputs default to Mono
when the left input is used. RCA phono connectors do
NOT have this option.

SUBGROUPS

These allow the logical assignment of groups of instruments
or vocalists so that they may be controlled by just one pair
of faders, or even a single fader, once individual
instruments’ relative levels have been balanced. They also
act as additional outputs with separate volume/level
controls – ideal for speaker fills or recording a number of
instruments to one tape track.

SECTION 1: Starting Out

5

L

T

INPUT
FADERS

GROUP
FADERS

Note: Inputs are
routed to Groups via
the routing switches
and Pan pots

FIG. 1.4

FIG. 1.5

STE-C

R

L
R

LEVEL

5

46

37

28

19

100

MIX

SUB

STE-C

STE-A

11

GAIN

22dB0

–+

0

33

66

99

12 12

66

99

12 12

22

33

44

SUB

–+

0

33

0

11

0N

MIX

HF

1515

LF

1515

AUX

1

PRE

100

AUX

2

POST

/PRE

100

AUX

3

POST

100

BAL

55

10

5

0

5

10

15

20

30

PFL

∞

A

THE MASTER SECTION

N Mix Outputs

Mix outputs provide left and right level control of the final
stereo mix. Many consoles feature mix insert points too,
allowing the connection of signal processors across the
whole mix.

O Monitor “Engineer’s” / Control Room Outputs

These let you listen to any solo, mix, submix from a group,
or the 2 Track tape return via an external amplifier and
speakers, or the headphone socket.

P 2 Track Tape Returns

Allow you to connect the outputs of your cassette or DAT
player and listen back to your completed masterwork. They
may also be used for playing pre-show music at a gig using
2-Track to Mix switch (not shown in illustration).

Q Aux Masters

These govern the overall output levels from the auxiliary
outputs and therefore the amount of signal going to an
effects unit or a musician’s foldback mix.

R AFL

Allows monitoring of the actual signal leaving the Aux
Masters.

S Meters

Normally they show mix output levels. When any Solo
button is pressed, the meters automatically switch to show
the solo level. They provide visual indication of what’s
going on in your mixer.

T Stereo Returns (see Stereo Inputs earlier in this section)

These allow signals from external equipment, such as effects
units, to be returned to the mixer and routed to the stereo
Mix or Groups, without using up valuable input channels.

U +48v or Phantom Power

Some microphones, known as condenser mics, require
battery power to operate. Alternatively the power may be
provided by the console. This is known as ‘phantom power’
and runs at 48vDC. Simply press “Phantom Power” and
any condenser mics connected will operate without the
need for batteries.

More Information on
Condenser Mics can be
found in Section 3 - Mixing
Techniques.

Further detail on mic
wiring may be found in
Section 7 - wiring.

V Headphones

Allow you to listen to
your mix without
annoying your
neighbours or being
distracted by ambient
sounds.

That’s it, the basic features
of your average mixing
console. If you found it a
little heavy going, don’t
despair: it does get easier!

SECTION 1: Starting Out

6

100

MIX INSERT

48V

PFL
AFL

100

100

AUX

1

AUX

2

AUX

3

0

5

10

15

20

25

30

40

∞

L SUB R

R

POST

PRE

0

5

10

15

20

25

30

40

∞

0

5

10

15

20

25

30

40

∞

L MIX R

SUB

TO

MIX

AFL

AFL

AFL

100

19

28

37

46

5

MONO SUM

PHONES

16
10

6
3
0

-3

-6

-9

-12

-16

REF +4dBu

POWER

100

19

28

37

46

5

100

19

28

37

46

5

2TK

LR

PFL

MAX
SUB

L

R

L

2TK

R

L

MONITOR

PHONES

MONO SUM

2TK

LEVEL

LRMIX

Caution: DO NOT ACTIVATE A GLOBAL PHANTOM
POWER SWITCH IF AN UNBALANCED SIGNAL
SOURCES IS CONNECTED TO ANY MIC INPUT.
Because of the voltage present on pins 2 and 3 of the XLR
connector, you will damage your microphone/signal source.

Always refer to your Mixer’s User Guide.

N

O

P

Q

R

S

U

V

FIG. 1.5

D. Signal Flow

Now the typical mixer features have been explained in
detail it is important to understand how they form
together. The route which a signal source takes through a
mixer is normally shown using one of two devices:
a block diagram or a signal flow diagram.

Both diagrams provide a ‘visual’ description of the key
elements of the mixing console. They allow you to identify
which components are used in the audio path and help the
engineer to “troubleshoot” when signal sources don’t appear
to be doing what they should! In simple terms, they are
electronic maps.

An example of a signal flow diagram is shown here. This
is the most basic representation of console layout, showing
a how a single sound source may pass through an input
strip to the various other parts of the mixer.

Block diagrams are slightly more complex, showing more
detail, electronic information, including the location of
resistors and capacitors, and the structure of the entire
console including bussing: an example is shown on page

37. Block diagrams also use a number of symbols to
represent electronic elements. A few minutes spent
understanding them some time during your journey
through this booklet will most definitely pay-off in future
mixing projects.

SECTION 1: Starting Out

7

FADER

PAN

MIX

FADER

AUX PRE

AUX PRE
MASTER

AUX POST

AUX POST

MASTER

SUB GROUP

FADER

SUB GROUP

TO MIX

AUX PRE

OUT

AUX POST

OUT

SUB GROUP

OUT

MIX

OUTPUT

MIC

LINE

MIC

PREAMP

HI PASS

FILTER

INSERT

EQ

ON/OFF

SWITCH

ROUTING

SWITCH

A Typical Signal Flow Path

FIG. 1.6

CONNECTING EQUIPMENT
TO YOUR MIXER

As we explained in the last section, it is the job of the mixer
to accept the various signal sources, set the levels and route
those signals to the correct destination.

We’ll now take a quick look at where to connect the
‘peripheral’ equipment that you will be using with your
mixer. If you have already created your own set-ups
successfully in the past, you should only need to
skim this part.

A. Input Devices

Microphones

All microphones should be connected via each
input’s XLR connectors. Do not use line inputs.

For more information on miking up individual instruments,
refer to sections 4 and 6 - PA Mixing and In the Studio.

Direct Injection Box (DI Box)

• A DI Box allows you to connect a guitar or bass directly
to the mixer’s input, rather than miking up the
instrument’s amp/speaker. This technique is often
preferred by musicians who require a “clean” sound.
The best DI boxes are ACTIVE and require Phantom
Power like condenser microphones. They should be
connected to XLR mic inputs.

SECTION 2: Connecting Equipment to your Mixer

8

NB: Although electric guitars and basses may be connected to a

mixer’s line inputs without danger, the results will be far from
ideal, because the IMPEDANCE of these instruments will
not match up with typical line levels. Direct connection
usually leads to a weak sound.

FIG. 2.1

MIC ON

GUITAR

AMP

MIC ON

DRUM KIT

VOCAL MIC

GUITAR

VIA

DI BOX

KEYBOARD, SYNTHESISER,
DRUM MACHINE OR SUBMIXER

EFFECTS UNIT

Aux Post

GRAPHIC EQ

POWER
SUPPLY

DIRECT OUTS

TO

MULTITRACK

TAPE

INPUT

EFFECTS UNIT

KEYBOARD, SYNTHESISER
OR SAMPLER

DIR DIR DIR DIR DIR DIR DIR DIR

LINELINELINE

INS2INS3INS4INS5INS6INS7INS8INS9INS10INS11INS

INS

1

COMPRESSOR/

LIMITER

MAIN OUTPUTS

SUB SUB

LRLR

LINE LINE LINE LINE LINE LINE LINE LINE LINE

GRAPHIC

EQ

POWER AMP

SURROUND/
FILL/
VOCAL
SPEAKERS
(or from
mono output)

POWER AMP

PA
SPEAKERS

AUX 1 AUX 2 AUX 3

GRAPHIC EQ

MICMICMICMICMICMICMICMICMICMICMICMIC

L

L

STE-C STE-D

R

R

L

R

12

L

A-STE-B

R

POWER AMP

ARTISTS FOLDBACK

MIX INSERT MONITOR MONO SUM

LRL

R

CASSETTE OR
DAT PLAYBACK

2TK

L

R

PHONES

HEADPHONES

>200R

9

Electronic Line Output Devices

• Keyboards, Drum Machines, CD Players, DAT
Machines, Wireless Mic Receivers, all provide line level
outputs, and should all be connected straight into the
Mixer’s Line Inputs. If some of your instruments are
STEREO connect their left and right outputs to a spare
stereo input. Alternatively connect to an adjacent pair of
mono inputs and Pan the inputs hard left and right to
create a stereo image.

B. Equipment Requiring Both

Inputs and Outputs

External effects units

Connect the input of your effects unit marked "mono" to
A POST FADER AUXILIARY OUTPUT. If you are
uncertain, Post fader auxiliaries are coloured blue on
Soundcraft mixers with the relevant channel aux pots
usually marked "post". The left and right outputs from the
effects unit should be connected to a pair of stereo returns,
or stereo inputs if stereo returns are not available. If
intensive EQ is required, use a pair of Mono Inputs.
Remember, the effects signal is no different from any other
audio signal – it still requires an input to the mixer.

See Section 3 Mixing Techniques or a detailed explanation of post
fader auxiliaries.

NB: YOU DO NOT HAVE TO CONNECT UP BOTH THE

LEFT AND RIGHT INPUTS OF YOUR EFFECTS UNIT
TO SEPARATE AUXs. Most units only require "pseudo-stereo"
operation and will mimic a stereo reverb or effect inside before
providing a stereo output to the mixer’s returns.

Signal Processors

Connect signal processors, such as compressors to the insert
jack using a special insert ‘Y’ cable. This allows the signal to
be sent and returned to the mixer using only one
connector.

Refer to section 7 for wiring information.

It is also possible to connect the processor to the console
without using the insert jacks by connecting an instrument
direct to the processor first. However, the advantage of
using processors in the mix/group or channel inserts is that
any level changes made by the processor can be monitored
by the mixers meters.

NB: A signal processor can be used in a channel to control one audio

source, across a group to control a number of audio sources or
across the entire mix.

Tape machines

Multitrack machines are used for initial track-laying in
either studio or live recording situations.
For more sophisticated work, a stand-alone machine offers
better sound quality and greater versatility than a cassette
multitracker. The new generation of digital multitracks are
also very attractive, but analogue, open-reel multitracks are
also capable of professional sounding results. Aim for a
minimum of eight tracks if your budget will allow.

Mastering Machines

Your final mix should be recorded on the best quality
machine that you can afford. A recording is only as good as
the weakest link in the chain, and a good cassette machine
is fine for demos, but for more serious work, consider a
DAT machine or perhaps a second hand, open-reel 2-track.

C. Output Devices

Amps and Speakers (Monitor and FOH)

Studio Monitoring

A high-powered hi-fi amp of around 50 watts per channel
is fine for home recording, but to ensure adequate head­room you should consider a well-specified rack mount amp.
Similarly, a pair of accurate hi-fi speakers will do the job,
but for more serious work we would recommend purpose­designed nearfield monitors. Always remember that no
matter how good the recording or performance, a poor
monitoring set-up will not allow you to make qualitative
judgements about the mix.

Headphones

When choosing headphones for monitoring, you’ll
obviously want a pair that give the best sound reproduction
for the price. But, bear in mind that in order for you to
fully concentrate on the mix, the headphones should
exclude outside noise - therefore open-back designs
will be of little use.

Furthermore, you could be wearing the headphones

for several hours at a stretch so comfort is essential.

NB: Make Sure that the IMPEDANCE of your headphones matches

the specification of your mixer.

PA Work

PA work requires high-powered, rugged, and honestly
specified amps and FOH (Front of House) speakers. The
power rating of the system will depend on the size of
venues you will be playing.
See PA Mixing, Section 4, for more information.

SECTION 2: Connecting Equipment to your Mixer

MIXING TECHNIQUES

A. Choosing the

Right Microphone

Microphone Types

The choice of microphone depends on the application that
the microphone will be used for and individual preference.
However, broadly speaking microphones fall into two main
types:

Dynamic Microphone -

• A robust design which
uses a thin diaphragm
attached to a coil of wire
arranged about a
permanent magnet. Any
variation in air pressure
on the diaphragm will
cause the coil to generate a minute electric current which
then requires amplification.
Dynamic mics are relatively inexpensive, rugged and
require no electrical power to operate. They are ideal for
all-round high sound pressure levels (SPL) and tend to be
used for live applications. However, they are not as
sensitive to high frequencies as condenser types.

Condenser Microphone -

• A type of microphone which picks up sound via a thin,
flexible diaphragm placed
in proximity to a metal
plate - as opposed to the
rigid diaphragm-and-coil
system used by dynamic
microphones. They need
power to operate - the
most common source
being +48v DC PHANTOM POWER.
Condenser mics are very sensitive to distant sounds and
high frequencies. Because of this sensitivity they are often
used in studio recording situations.

N.B. +48v Phantom power is used to charge the diaphragm and

plate. It also supplies a small amplifier which boosts the small
voltages generated by diaphragm movements.

Microphone Pick-up Patterns

A pick-up (Polar) pattern refers to the area(s) from which a
microphone "picks up" its sound. It is important to choose
the right pattern for your application, or you may pick up
sounds from areas you don’t want or lose sound
information you need.

Omni Pattern

The most basic type of
microphone pattern.

• A 360° polar response which
picks up sound equally in all
directions.
This pattern is ideal for
picking up groups of vocals,
audiences, ambient sounds but is most susceptible to
feedback.

Cardioid Pattern

• The ‘heart-shaped’ polar
response of a microphone
meaning that most of the
sound is picked up
from the front.
Used for most basic
recording or in any situation
where sound has to be picked up from mainly one
direction. Dynamic cardioid mics are mostly used for live
applications because they help reduce unwanted spill
from other instruments, thus reducing the risk of
feedback.

Hyper-cardioid

• Similar to a cardioid pattern but
with greater directionality.
Used for live vocal microphones
because it provides the greatest
protection from unwanted spill
and feedback.

Figure of Eight

• Sound is picked up
from the front and
back but not from
the sides.
This pattern is
used mainly in
studios for picking
up two ‘harmony’
vocalists, or solo vocalists who
require some room ambience.

SECTION 3: Mixing Techniques

10

+V

–V

OUTPUT

FIG. 3.1

FIG. 3.3

FIG. 3.4

FIG. 3.5

FIG. 3.6

FIG. 3.2

B. Setting Up a Basic Mix

Setting the Gain

Input gain is designed to take an audio signal, and adjust it
to the level which the mixer understands.

All audio circuits, mixers included, produce a low level of
electronic noise or hiss, and while this can be made very
low by careful design, it can never be completely
eliminated. It is also true that any audio circuit can be
driven into distortion if the input is too high in level; hence
care has to be taken when setting the input level so as to

preserve the best possible sound quality. Ideally the input
signal should be as high in level as possible while still
leaving a margin of safety to prevent distortion on loud
sections. This will ensure that the signal is large enough to
render the background noise insignificant, whilst keeping
the signal clean. The remaining safety margin is known as
Headroom.

To set the gain on the mixer;

• Press the PFL/Solo switch on the

relevant input.

• Adjust gain/input sensitivity until

meters read within the yellow (‘3’ to

‘6’ on meter scale). This allows for

the extra 10dB of gain that is

available on Soundcraft input faders.

• Release PFL/Solo.

• Repeat for all other inputs.

NB: EQ affects gains settings. If you adjust

the EQ you will need to re-check your
gain level using the above method.

Once you have optimised the gain
your mixer will give the best possible
signal quality with the minimum of
noise and distortion.

Balancing Fader Levels

Faders allow you to make fine adjustments to your sounds
and act as a visual indication of the overall mix levels.

It is important to keep your input faders around the ‘0’
mark for greater control. This is because fader scales are
typically logarithmic and not linear, so if your fader
position is near the bottom of its travel then even a small
movement will lead to huge leaps in level. Similarly try not
to have your fader at the top of its travel because this will
leave you no room to further boost the signal.

See diagram below.

Balancing Output Levels

Master Outputs

Set your master outputs to ‘0’ on the scale. There are
two reasons for this:

1 You have the maximum fader travel for fading out your

mix.
2 If your faders are set below ‘0’ you will not be getting the

full benefit from the meters because you will only be

using the first few LEDs on the meter scale.

SECTION 3: Mixing Techniques

11

0

-20

+6

-30

-40

-50

-60

10

5

0

5

10

15

20

30

∞

LOW

LEVEL

SETTING

FADER

OFF

TYPICAL
SETTING

SOLO

Linear level

adjustment from

-20 to +10dB

TYPICAL GAIN SETTINGS FOR DIFFERENT INPUTS

NB: Your mixer is not an amplifier. So the master output faders
should be set to maximum (‘0’ on scale). If extra output is required,
then turn up your amplifier.

FIG. 3.7

FIG. 3.8

C Using the Mixer’s EQ

Equalisation is useful for making both corrective and
creative changes to a sound, but it needs to be used with
care. Corrective applications include making tonal changes
to compensate for imperfect room acoustics, budget
microphones or inaccurate loudspeaker systems. While
every effort should be made to get the sound right at
source, this is less easily achieved live than in the more
controlled conditions of the recording studio. Indeed, the
use of equalisation is often the only way to reach a
workable compromise in live situations.

Creative applications, on the other hand, are equally as
valid in the recording studio as they are live, and an
equaliser with a swept midrange control is infinitely more
versatile than one that has simple high and low
controls. The only rule of creative equalisation
is - ‘If it sounds good, it is good!’

Fixed EQ

Most people will be familiar with the operation
of high and low frequency controls; they work
in a similar manner to the tone controls on a
domestic stereo system.

In the centre position the controls have no
effect, but rotate them clockwise and they will
provide boost, or rotate them anticlockwise
and they provide cut. Despite their apparent
simplicity, however, high and low controls should be used
with caution as overuse can make things worse. Adding a
small amount of high or low boost should be enough to
add a touch of brightness or warmth to a sound, but a
quarter of a turn should be sufficient, especially where the
low control is concerned.

The drawback with fixed controls often lies in the fact
that you may want to boost just a particular sound such as
the punch of a bass drum or the ring of a cymbal, whereas
a fixed control influences a relatively large section of the
audio spectrum. Apply too much bass boost and you could
find the bass guitar, bass drum and any other bass sounds
take on a flabby, uncontrolled characteristic which makes
the mix sound muddy and badly defined. This is because
sounds occupying the lower mid part of the spectrum are
also affected. Similarly, use too much top boost and the
sound becomes edgy with any noise or tape hiss being
emphasised quite considerably.

In a PA situation, excessive EQ boost in any part of the
audio spectrum will increase the risk of acoustic feedback
via the vocal microphones.

SECTION 3: Mixing Techniques

12

LF

MID

HF

6kHz240

1.2k

6kHz240

1.2k

1515

12 12

99

66

33

0

–+

1515

12 12

99

66

33

0

–+

1515

12 12

99

66

33

0

–+

1515

12 12

99

66

33

0

–+

1515

12 12

99

66

33

0

–+

1515

12 12

99

66

33

0

–+

FIG. 3.9

THE FREQUENCY RANGE OF DIFFERENT

INSTRUMENTS AND WHICH EQ BANDS AFFECT THEM