MMPLS501

Reinforce Live Sound

RQF Level: 5 Learning Hours

60
Credits: 6

Sector: ICT and Multimedia

Trade: Multimedia Production

Module Type: Specific

Curriculum: ICT MMP5001 TVET Level 5 in multimedia production

Copyright: © Rwanda TVET Board, 2023

Issue Date: May ,2024 2024-25
Elements of competency Performance criteria

1. Install sound system

1.1. Environment is properly assessed based on event requirements.

1.2. Equipment is properly selected based on assessed environment

1.3. The site is properly installed according to its acoustics and audience seating
arrangement.

1.4. Audio components are correctly connected based on audio system

schema/block diagram component.

2. Control sounds
2.1 Sounds are clearly monitored based sound quality.

2.2 Sound system is properly troubleshoot based on its technical issues.

2.3 Performers are properly guided based on stage monitoring techniques.

3. Maintain sound equipment

3.1. Sound equipment is properly dismantled and checked in line with safety
and efficiency.

3.2. Audio equipment is properly cleaned based on cleaning procedures.

3.3. Audio equipment is properly stored based on manufacturer’s

instructions
Learning outcome 1: Install sound system
Introduction to live sound

Live sound refers to the audio produced and experienced in real time, as opposed to recorded or
pre-recorded sound. It typically involves a live performance, such as a concert, musical, or
theatrical production, where musicians, singers, or actors perform in front of an audience.

Key characteristics of live sound:

 Spontaneity: Live performances are characterized by their unpredictability and

spontaneity, as performers may make adjustments or improvise during the show.
 Direct experience: Audiences experience live sound directly, without the mediation of
recording or playback equipment.
 Interaction: Live performances often involve interaction between the performers and the
audience, creating a unique and immersive experience.

Reinforcing live sound refers to the process of enhancing the sound quality and volume of a live
performance using electronic equipment. This is typically done to ensure that the audience can
hear the music and vocals clearly, even in large venues or outdoor settings.

Common techniques used to reinforce live sound:

 Microphones: Capturing the sound from instruments and vocals.

 Mixers: Combining the signals from multiple microphones and adjusting their levels.
 Amplifiers: Increasing the volume of the sound.
 Speakers: Delivering the amplified sound to the audience.
 Equalizers: Adjusting the frequency balance of the sound.
 Compressors: Controlling the dynamic range of the sound.
 Effects processors: Adding various effects, such as reverb, delay, or distortion.

Indicative content 1.1. Assessing the Environment for Reinforcing Live Sound
Assessing the Environment for Reinforcing Live Sound refers to the process of evaluating the
physical characteristics of a venue or outdoor space to determine the best approach for ensuring
optimal audio quality during a live performance or event. This assessment is essential for
ensuring that the sound system is properly designed, installed, and adjusted to overcome any
challenges posed by the environment.

Here are the key factors to consider:

o Sound System

 Type: Determine if a passive or active system is suitable based on the venue size, power
requirements, and budget.
 Components: Ensure the system includes speakers, amplifiers, mixers, microphones,
cables, and accessories.
 Capacity: The system should be able to handle the expected sound levels and audience
size.

o Types of PA System

 Portable PA: Ideal for small venues and outdoor events.

A portable public address (PA) system is a self-contained audio system that can be easily moved
and transported to different locations. These systems are designed to provide clear and
amplified sound for public announcements, presentations, events, and other gatherings.

Portable PA systems typically include:

 Amplifier: This increases the volume of the audio signal.

 Speakers: These deliver the amplified sound to the audience.
 Microphone: This captures sound from a speaker or performer.
 Mixer: This combines and controls the levels of multiple audio sources.
 Power supply: This provides electricity to the system.

 Large-scale PA: Used for concerts, festivals, and arenas.

Large-scale public address systems, on the other hand, emphasize the sheer size and capacity
of the system. These systems are often used in very large venues, such as arenas or stadiums,
where they need to deliver sound to a massive audience. They may incorporate advanced
technologies like beamforming or digital signal processing to ensure clear and intelligible
sound coverage even in challenging acoustic environments.

 Distributed PA: Provides even sound coverage in large spaces.

Distributed public address (PA) systems typically refer to systems that are spread out over a
large area, with multiple speakers or loudspeakers placed at various locations. This allows for
even sound coverage across a wide space, such as a stadium, airport, or theme park. The goal of
a distributed PA system is to ensure that everyone in the area can hear the announcements or
messages clearly and consistently.

o Types of Events

 Music concerts: A music concert sound system requires a complex network of equipment
designed to deliver high-quality audio to a large audience.

These systems typically consist of several key components:

1. Microphones:

 Vocal microphones: Capture the singer's voice.

 Instrument microphones: Capture the sound of various instruments.
 Wireless microphones: Offer freedom of movement for performers.

2. Mixers:
  Analog or digital mixers: Combine and balance the signals from multiple microphones
and other audio sources.
 Features: Equalizers, compressors, effects, and routing capabilities.

3. Amplifiers:

 Power amplifiers: Increase the volume of the audio signal.

 Types: Tube amps, solid-state amps, and hybrid amps.

4. Speakers:

 Main speakers: Deliver the primary sound to the audience.

 Subwoofers: Provide deep bass frequencies.
 Monitor speakers: Used by performers on stage to hear themselves and the band mix.

5. Signal Processing:

 Equalizers: Adjust the frequency balance of the sound.

 Compressors: Control the dynamic range of the sound.
 Effects processors: Add various effects like reverb, delay, or distortion.

6. Audio Cables:

 Connect all components of the system.

 Types: XLR, TRS, RCA, and speak on.

7. Power Distribution:

 Ensure adequate power supply to all components.

 Use power conditioners to protect equipment from voltage fluctuations.

8. Stage Monitoring:

 Allows performers to hear themselves and the band mix.

  Uses in-ear monitors or floor monitors.

9. Acoustic Treatment:

 Reduces unwanted reflections and echoes in the venue.

 Uses sound-absorbing materials like acoustic panels.

 Corporate events: May need a more versatile system for speeches, presentations, and
music.

A corporate event sound system is essential for ensuring that your message is heard clearly and
effectively. Whether you're hosting a small meeting or a large conference, the right sound system
can make a big difference in the overall success of your event.

Key Components of a Corporate Event Sound System: Microphones, Mixer, Amplifier, Speakers,
Wireless microphones, Audio cables, Signal processors

 Theater productions: Require a system that can integrate with stage lighting and effects.

A theater production sound system is a crucial component of any stage performance. It ensures
that the audience can clearly hear the dialogue, music, and sound effects, enhancing the overall
viewing experience.

Key Components of a Theater Sound System

1. Microphones: These capture the sound of actors, musicians, and other sound sources on
stage.
2. Mixers: These devices combine and control the levels of multiple audio sources, allowing
for balance and equalization.
3. Amplifiers: These increase the volume of the audio signal.
4. Speakers: These deliver the amplified sound to the audience.
5. Equalizers: These adjust the frequency balance of the sound to compensate for room
acoustics and desired effects.
 6. Effects processors: These add various effects, such as reverb, delay, or distortion, to
enhance the sound.
7. Wireless microphones: These allow for freedom of movement for actors and musicians.
8. Digital audio workstations (DAWs): These software programs can be used to record, edit,
and mix audio.

Considerations for Theater Sound Systems

 Room acoustics: The shape and size of the theater can affect sound quality. Acoustic
treatments may be necessary to improve sound clarity.
 Audience size: The size of the audience will determine the required speaker power and
placement.
 Type of performance: Different types of performances (e.g., musicals, plays, concerts)
may have different sound requirements.
 Budget: The budget will influence the choice of equipment and accessories.

o Venue Size and Layout

 Capacity: Determine the maximum audience size to ensure adequate sound coverage.
 Shape: Consider the venue's shape (e.g., rectangular, circular) to optimize speaker
placement.
 Obstacles: Identify any potential sound-absorbing or reflecting surfaces.

o Target Audience

 Preferences: Understand the audience's expectations and preferences for sound quality.
 Age: Consider the age demographic, as hearing sensitivity varies.
 Cultural factors: Be aware of cultural preferences and sensitivities regarding sound.

o Power Source

 Availability: Ensure access to a reliable power source or consider generators if necessary.

  Capacity: The power source must be able to handle the system's requirements.

o Venue Acoustics

 Natural acoustics: Assess the venue's inherent acoustics (e.g., reverberation, echo).
 Sound treatment: Determine if acoustic treatment (e.g., soundproofing, absorption) is
needed.

o Logistics and Setup Time

 Access: Consider access to the venue and any restrictions on equipment movement.
 Setup time: Allocate sufficient time for system setup and testing.

o Budget

 Constraints: Determine the available budget for the sound system and related expenses.
 Priorities: Prioritize components based on the event's requirements and budget.

Indicative content 1.2. Equipment selection

Equipment selection in a sound system refers to the process of choosing the appropriate
components to meet the specific needs of a particular application. This involves considering
factors such as:

Factors to consider for better selection of equipment”

 Purpose: What is the sound system being used for (e.g., live music, public
announcements, home theater)?
 Size and venue: How large is the space where the system will be used? What are the
acoustic characteristics of the venue?
 Budget: How much money is available for the system?
 Desired sound quality: What level of audio fidelity is required?
 Portability: Does the system need to be easily transportable?
  PA Input Devices

PA input devices are the components of a public address (PA) system that are used to capture
and input audio signals. These devices allow you to connect various sources of sound to your PA
system, such as microphones, instruments, and other audio equipment.

 Microphones:
o Dynamic microphones: A dynamic microphone is a type of microphone that uses
electromagnetic induction to convert sound waves into electrical signals. It
consists of a diaphragm, a coil, and a magnet. When sound waves strike the
diaphragm, it vibrates, causing the coil to move within the magnetic field. This
movement induces an electrical current in the coil, which is then amplified and
transmitted.
They are known to be robust/strong and durable, suitable for live performances.

Some popular examples of dynamic microphones include:

 Shure SM57

 Shure SM58

 Sennheiser e 905
 AKG D5

o Condenser microphones: Condenser microphones are a type of microphone that

uses a capacitor (also known as a condenser) to convert sound waves into
electrical signals. They are highly sensitive and capable of capturing a wide range
of frequencies, making them popular for recording and studio applications.
There are known to be sensitive and detailed, ideal for recording and studio applications.

o Ribbon microphones: Ribbon microphones are a type of microphone that uses a thin
metal ribbon suspended between two magnetic fields to convert sound waves into
electrical signals. The ribbon vibrates in response to sound waves, inducing an electrical
current in the magnetic field.

How it works:

1. Sound waves strike the ribbon: The sound waves cause the ribbon to vibrate.
2. Ribbon moves within magnetic fields: As the ribbon vibrates, it moves within the
magnetic fields created by the magnets.
3. Electrical current is induced: The movement of the ribbon within the magnetic
fields induces an electrical current in the ribbon.
 4. Signal is amplified: The electrical signal is amplified and transmitted as an audio
signal.

o Wireless microphones: Offer freedom of movement for performers.

 Line inputs: Line inputs in a sound system are designed to receive audio signals from
various external sources that have already been amplified and processed. These inputs
typically accept balanced audio signals, which are less susceptible to noise and
interference than unbalanced signals.
Common sources of line inputs include:

 CD players: These devices output a line-level audio signal.

 MP3 players: Similar to CD players, MP3 players also have line-level outputs.
 Computers: Computers can output audio through line-level outputs or USB audio
interfaces.
 Mixers: Mixers often have line-level inputs to connect to other audio sources.
 Synthesizers: Synthesizers can output a line-level audio signal.
 Other audio equipment: Many other audio devices, such as turntables or tape decks, may
have line-level outputs

 Instrument inputs: Instrument inputs in sound reinforcement systems are designed to

accommodate the specific characteristics of various musical instruments. These inputs
often have different impedance and sensitivity requirements compared to line inputs,
which are designed for amplified signals.

Common types of instrument inputs include:

 Guitar inputs: These inputs are specifically designed for electric guitars and have a high
impedance to match the output of the guitar's pickup.
 Bass guitar inputs: Similar to guitar inputs, but with a slightly different impedance to
accommodate the lower frequencies of the bass guitar.
 Keyboard inputs: These inputs are designed for keyboards and synthesizers, and may
have different impedance requirements depending on the type of instrument.
 Other instrument inputs: Some sound systems may have inputs specifically designed
for other instruments, such as violins, drums, or wind instruments.

Instrument inputs are typically used to:

 Connect musical instruments directly to the sound system: This eliminates the need
for additional amplification or processing.
  Provide phantom power: Some instrument inputs can provide phantom power, which
is required for certain types of condenser microphones and other electronic devices.
 Adjust gain and tone: Many instrument inputs have built-in gain controls and tone
controls that can be used to adjust the sound of the instrument

 PA Output Devices

PA output devices in a sound system are the components responsible for delivering the amplified
audio signal to the audience. These devices typically include:

 Speakers: This is the most common type of PA output device. Speakers come in various
sizes and configurations, including full-range speakers, subwoofers, and stage monitors.
 Headphones: Headphones can be used for monitoring the audio signal, but they are not
typically considered PA output devices in a live sound context.

The choice of PA output devices depends on the size of the venue, the desired sound quality, and
the type of performance. For example, a large outdoor concert may require multiple full-range
speakers and subwoofers to deliver sufficient sound coverage to the audience. A smaller indoor
performance may only require a few speakers and stage monitors.

Key considerations when selecting PA output devices:

 Power handling: The speakers must be able to handle the power output of the amplifiers.
 Frequency response: The speakers should be able to reproduce the full range of
frequencies required for the performance.
 Sensitivity: The speakers' sensitivity determines how loud they will be for a given amount
of power.
 Coverage: The speakers should be able to provide even sound coverage throughout the
venue.
 Weight and portability: If the PA system needs to be portable, the speakers should be
lightweight and easy to transport.
Types of Speakers Used in Sound Systems

Speakers are the primary output devices in a sound system, responsible for delivering the
amplified audio signal to the audience. There are several types of speakers used in sound
systems, each with its own characteristics and applications.

 Full-Range Speakers

 Description: Full-range speakers are designed to reproduce a wide range of frequencies,

from low to high.

Full-range speakers typically have a frequency response of 20 Hz to 20 kHz. This means

they can reproduce sounds from the lowest audible frequencies (20 Hz) to the highest
audible frequencies (20 kHz).

This wide frequency range allows full-range speakers to produce a balanced sound with
good bass, midrange, and treble response.

 Applications: Suitable for a variety of applications, including live sound, home audio, and
public address systems.
 Advantages: Versatile and can be used in various settings.
 Disadvantages: May not provide the same level of bass response as dedicated
subwoofers.

 Midrange speakers are designed to reproduce frequencies in the mid-range of the audio
spectrum, typically between 200 Hz and 2 kHz. This range includes most human speech
and many musical instruments.

Midrange speakers are often used in conjunction with full-range speakers or subwoofers to
create a complete audio system. They provide clarity and detail in the mid-range frequencies,
which can be essential for understanding speech and enjoying music.

 Woofers and subwoofers

  Description: Subwoofers are specialized speakers designed to reproduce low-frequency
sounds (bass).

Subwoofers typically have a frequency response of 20 Hz to 120 Hz. This means they are
specifically designed to reproduce the lowest frequencies, which are often referred to as
"bass."

 Applications: Often used in conjunction with full-range speakers to provide deeper and
more powerful bass.
 Advantages: Enhance the overall sound quality and impact of the audio.
 Disadvantages: Require additional space and power.

Woofers and subwoofers are both types of speakers designed to reproduce low-frequency
sounds, but they have distinct differences in their range and purpose.

Key Differences

 Frequency Range:
o Woofers: Typically reproduce frequencies between 40 Hz and 2 kHz.
o Subwoofers: Specialize in reproducing frequencies below 200 Hz, often as low as
20 Hz.
 Size:
o Woofers: Can vary in size, but are generally smaller than subwoofers.
o Subwoofers: Often larger to accommodate the larger cone size needed to produce
deep bass.
 Purpose:
o Woofers: Are often part of a multi-driver speaker system, handling the mid-bass
and low-mid frequencies.
o Subwoofers: Are dedicated to reproducing the very lowest frequencies, adding
depth and impact to sound.

 Tweeter speaker
Tweeters are specialized speakers designed to reproduce the highest frequencies, typically above
2 kHz. They are characterized by their small size and their ability to produce clear and detailed
high-frequency sounds.

Key characteristics of tweeters:

 High-frequency response: Tweeters are specifically designed to accurately reproduce

sounds in the high-frequency range.
 Small size: Tweeters are often smaller than other types of speakers, allowing them to be
placed in various locations.
 Clarity and detail: Tweeters can provide excellent clarity and detail in high-frequency
sounds, such as cymbals, bells, and high-pitched vocals.

 Coaxial Speaker

Coaxial speakers are a type of speaker that combines a tweeter and a woofer into a single unit.
The tweeter is typically placed in the center of the woofer, allowing both drivers to share a
common enclosure and acoustic space.

 Horn Speaker

Horn loudspeakers are a type of speaker that uses a horn-shaped acoustic waveguide to increase
the efficiency and directivity of sound reproduction. The horn is designed to gradually increase
in size from the throat to the mouth, which helps to focus the sound and increase its intensity.

Key characteristics of horn loudspeakers:

 High efficiency: Horn loudspeakers are highly efficient, meaning they can produce a high
volume of sound with relatively low power input.
 Directivity: Horn loudspeakers have a narrow beam width, which means they focus the
sound in a specific direction. This can be beneficial in applications where it is important
to target the sound at a particular audience.
 Wide frequency response: Horn loudspeakers can be designed to reproduce a wide range
of frequencies, from low to high.

 Signal Processors

Signal processors are electronic devices used in live sound reinforcement to modify and
enhance audio signals. They allow sound engineers to shape the sound of instruments,
vocals, and other audio sources to achieve desired effects and improve overall sound
quality.

Common types of signal processors used in live sound reinforcement include:

 Equalizers: Equalizers are signal processors used in sound systems to adjust the
frequency balance of audio signals. They allow you to boost or cut certain
frequencies to shape the overall sound of instruments, vocals, or other audio
sources.

Common used types of equalizers:

1. Graphic equalizers: These have a series of fixed-frequency bands that can be

adjusted to boost or cut specific frequencies.
 2. Parametric equalizers: These allow you to adjust the frequency, gain, and
bandwidth of each band more precisely.

 Compressors: Control the dynamic range of the sound, reducing loud peaks and
boosting quieter signals.

Common controls found on compressors:

 Threshold: This control sets the level at which the compressor starts to reduce gain.
Signals below the threshold are unaffected.
Ratio: This control determines how much the compressor reduces gain for signals above
the threshold. A higher ratio means more compression.
Attack: This control sets the time it takes for the compressor to start reducing gain after
a signal exceeds the threshold.
Release: This control sets the time it takes for the compressor to stop reducing gain
after a signal falls below the threshold.
Output: This control adjusts the overall level of the compressed signal.
Meter: This indicates the amount of compression being applied to the signal.

 Gates: are signal processors used in sound systems to reduce or eliminate

unwanted noise and background noise. They work by automatically muting or
reducing the volume of signals below a certain threshold.

Gates automatically mute or reduce the volume of signals below a certain threshold, reducing
noise and background noise.

How gates work:

1. Threshold setting: The gate's threshold is set to a specific level.

2. Signal monitoring: The gate continuously monitors the incoming audio signal.
3. Signal reduction: If the incoming signal falls below the threshold, the gate reduces or
mutes the signal.
4. Signal recovery: When the signal rises above the threshold, the gate allows the signal to
pass through.

Common controls found on gates:

Threshold: This control sets the level at which the gate starts to reduce or mute the signal.
Signals below the threshold are affected.
Range: This control determines how much the gate reduces the volume of signals below
the threshold. A higher range means more reduction.
Attack: This control sets the time it takes for the gate to start reducing the volume after
a signal falls below the threshold.
Release: This control sets the time it takes for the gate to stop reducing the volume after
a signal rises above the threshold.
Output: This control adjusts the overall level of the gated signal.

 De-essers: De-essers are signal processors specifically designed to reduce

sibilance, which is the hissing sound that can occur in vocals, especially when
pronouncing "s" and "sh" sounds. They work by reducing the gain of high-
frequency sounds that fall within the sibilance range.

How de-essers work:

o Sibilance detection: De-essers use a frequency analyzer to detect sibilant

sounds.
o Gain reduction: When a sibilant sound is detected, the de-esser reduces
the gain of the high-frequency components of the signal.
o Signal restoration: Once the sibilant sound has passed, the de-esser
restores the gain of the signal to its original level.

De-esser controls:

Threshold: This control sets the level at which the de-esser starts to reduce
gain.
Frequency: This control sets the frequency range that the de-esser targets.
Range: This control determines how much the de-esser reduces gain.
Attack: This control sets the time it takes for the de-esser to start reducing
gain.
 Release: This control sets the time it takes for the de-esser to stop reducing
gain.

 Reverb units: Simulate the acoustic space of a room or other environment.

Reverb units are signal processors used in sound systems to simulate the acoustic space of a
room or other environment. They add a sense of depth, richness, and naturalness to the sound
by creating artificial reflections and echoes.