The document provides information about technical stage operations related to sound. It describes various components of a sound desk including 24 input channels, gain controls, equalization controls, auxiliary outputs, pre-fade listening, channel volumes, and master volume. It also discusses active and passive speakers and their differences. Various cable types are explained, including XLR cables, phono leads, jack leads, and SpeakON cables.

1. Unit 65 Technical Stage Operations - Sound
By Anna Smith

2. Sound Desk
A sound desk is a electronic device for mixing, routing, and
changing the level, timbre/dynamics of audio signals.
Sound Desks are used in many scenarios including
recording studios, public address systems (PA
System), sound reinforcement
systems, broadcasting, television, and film post-production.
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There are 24 input channels
6 Channels can be Mono/Stereo these are located at
the at the back of the sound desk
Microphones only take up one channel (Mono)
The Gain is located at the top of the sound desk, this
controls the frequency of sound the desk allows in

3. Sound Desk
The gain controls the amount of sound that
goes into the desk. The gain is directly linked
to the channel volume control. The gain
allows more or less volume to be given to the
speakers therefore controlling the loudness of
the input.
The EQ is used to control the sound for a
specific input. There are two dials for mid
frequency range (250 – 5Khz). There is a dial
for high frequency and the last is for the base.
The aim of the EQ is to make the input sound
as naturalistic as possible e.g. a microphone
might make a performer sound tinny
therefore the EQ dials would need to be
adjusted
People on stage need to hear what they sound
like, this is important because they need to stay in
time, be aware of their volume and the other people
around them. The Aux allows us to control what the
actor/singer hears through their headset, this is
important because it will differ from what the
audience will hear.

4. Sound Desk
The PFL button should always be switched on
when trying to adjust channel volume. The PFL
button allows us to see the lights on the peak
monitor (RHS). This is important because the
volume should not reach a point where the lights
are flashing into the red zone; this can be
dangerous and blow the speakers.
The channel volume allows us to control the
volume of each individual input by itself. This is
important especially in live performances such
as a musical theatre production where by more
than one person is singing in unison. We want it
to sound as though both singers are on a level
playing field but one may be weaker than the
other. Therefore we would adjust that persons
channel volume so it is higher than their duet
partners so that the audience feel they are both
as strong as each other.
The master volume controls the sound output for
the entire desk. Without the master volume being
adjusted no sound will be heard even if the channel
volume is adjusted,

5. Sound Desk
Step by Step Guide to Setting Up the Sound Desk:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Turn the desk on
Set all dials to the top
Turn master volume to Zero
Turn the channels ON which you are using (Should glow orange)
Turn the PFL buttons ON for the channels you are using (Should
also glow orange)
Turn gain down to -Sixteen
Bring the channel volume up to Zero
Increase the gain to increase the depth of volume (Use the peak
monitor on the RHS so that the lights go into the orange
intermittently but NOT the red)
Adjust the EQ high/Low frequency (And base if needed)

6. Speakers
Active Speakers:
Passive Speakers:
Once active speakers are plugged in to a power source
they should automatically work without hesitation (if
the public address system has been set up correctly).
This is because active speakers already have a 13 watt
amp built in to them.
Passive speakers do not contain a power source built
inside them. Passive speakers need an external
amplifier so they can work when plugged into a power
source.
When using active speakers you would mainly use XLR
cables.
When using passive speakers you need to use a speakon
cable.
I would use a active speaker over a passive speaker if I was
taking part in a music gig in my local pub. This is because I
would have a lot to carry already and taking a passive
speaker would add to my load as I would also need to carry
an external amplifier, where as active speakers already
have them built in.
I would use a passive speaker over an active speaker if I
was hosting the biggest musical festival in the country. I
would do this because although active speakers contain an
amplifier built different bands may preform at different
volumes/frequencies and therefore need different
amplifiers in order to not blow the speakers

7. XLR Cable
The XLR cable is a electrical connector, primarily found on professional
audio, video, and stage lighting equipment. The connectors are circular in
design and have between 3 and 7 pins. They have a male and female end
and the male always goes into the female end. The male end has 3 pins
where as the female part has 3 holes (as seen on the pictures below).
An example of when an XLR cable is used is to connect the sound desk to
the speakers. The XLR cable goes from the output of the desk to the input
of the speakers, one to the left and one to the right.

8. Phono Lead
Phono leads are very common for connecting audio and even video
equipment. Most domestic DVD and Audio equipment uses this format of
connector. Phono cables are used to connect two pieces of hifi together to
transmit an analogue audio signal, such as a cd player and amplifier.
They are a twin cable with two single-pin plugs on each end, the plugs are
coloured to allow correct connection of left and right stereo channels at
both ends (usually they are white and red, as seen in picture below).
When setting up a public address system Phono leads are usually plugged
into the output of a device e.g. CD player (the red goes to the right and the
white to the left) and the input of channels 1 and 2 on the sound desk.

9. Jack Lead
A Jack Lead is the most common connection to be found on musical
equipment. The quarter inch jack is the type of connection that is used on
electric guitars and guitar amps. The plug itself is always ¼” or 6.3mm
jack, with a single black hoop called an insulating ring towards its tip (this
indicates that this is a mono or single channel connection).
The ¼ inch Jack tends to be found on audio interfaces and recording
equipment, mixing desks and PA equipment.

10. SpeakON
A Speakon (sometimes stylized speakON) is a type of cable connector
mostly used in professional audio systems for connecting loudspeakers to
amplifiers. They lock into their sockets with a twisting motion, making
them significantly less prone to disconnection than standard phone plugs.
They are shielded from human touch, preventing electrical shock from a
high-powered amplifier. The contacts do not short out during connection
or disconnection which can be a benefit when working with sound
equipment that is in operation.