Toa CS-64, F-160, F-240, F-505, F-605 User Manual
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TOA ElectronicsSpeaker Guide
TOA Electronics Speaker Guide
Table of Contents
List of Figures
..................................................................................................................... viii
Chapter 1: Getting Started: System Design Steps
Chapter 2: System Applications
Paging .................................................................................................................12
Speech Reinforcement ........................................................................................12
Background Music ..............................................................................................13
Foreground Music...............................................................................................13
Voice/Music Combinations ................................................................................13
Presentation Audio..............................................................................................13
Chapter 3: Speaker Types
Ceiling Speakers .................................................................................................14
Wall-mount Speakers..........................................................................................14
............................................................................................14
...............................................................................12
.........................................10
In-wall Speakers..................................................................................................15
Paging Horns.......................................................................................................15
Subwoofers .........................................................................................................16
Chapter 4: Audio Basics
The Decibel .........................................................................................................17
Sound Pressure Level.................................................................................17
Power, Volume, and Decibels....................................................................17
Sensitivity Ratings and the Decibel ...........................................................18
Attenuation over Distance: Inverse Square Law .......................................18
Speech Intelligibility, Acoustics, and Psychoacoustics ......................................18
Masking, Upward Masking, and the Haas Effect ......................................19
Reverberation.............................................................................................19
Equalization ........................................................................................................20
...............................................................................................17
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TOA Electronics Speaker Guide
Chapter 5: Using Speaker Specifications
...........................................................21
Determining Maximum Output: Sensitivity and Power Handling .....................21
Coverage Angle ..................................................................................................23
Frequency Response ...........................................................................................23
Chapter 6: Layout and Spacing for Distributed Speaker Systems
Ceiling Speakers .................................................................................................24
Speaker Coverage Area .............................................................................24
Coverage Area and Ceiling Height............................................................25
Coverage Density vs. Budget.....................................................................25
Layout Patterns ..........................................................................................26
Wall-Mount Speakers .........................................................................................28
Speaker Coverage Area .............................................................................28
Speaker Spacing and Layout Pattern .........................................................29
Subwoofers .........................................................................................................29
.......24
Chapter 7: Amplifier Selection
Direct Connection or Constant Voltage..............................................................30
Power Requirements ..................................................................................30
Subwoofer Power Requirements ...............................................................31
Examples.............................................................................................................31
High-Quality Paging System .....................................................................31
Outdoor Paging System .............................................................................32
High-Quality Multi-Purpose System .........................................................33
..................................................................................30
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TOA Electronics Speaker Guide
Chapter 8: Speaker Application Tables
How to Use This Section ....................................................................................34
All Speakers...............................................................................................34
Ceiling Speakers ........................................................................................34
Wall-mount Speakers.................................................................................35
Ceiling-mount Speakers......................................................................................36
F-101C/M...................................................................................................36
F-121C/M...................................................................................................37
PC-671R/RV..............................................................................................38
H-1 .............................................................................................................39
H-2/WP ......................................................................................................41
Wall-mount Speakers..........................................................................................42
BS-1030B/W..............................................................................................42
BS-20W/WHT ...........................................................................................43
CS-64, CS-154, CS-304.............................................................................44
................................................................34
F-160G/W, F-240G/W...............................................................................47
F-505G/W, F-605G/W...............................................................................49
H-3/WP ......................................................................................................51
Paging Horns.......................................................................................................52
SC-610/T, SC-615/T, SC-630/T, SC-650..................................................52
Appendix A:Wire Size Charts
.................................................................................... A-1
Appendix B: Speaker Mounting Hardware and Accessory Reference
A-2
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TOA Electronics Speaker Guide
List of Figures
3-1 F-101C/M, F-121C/M ceiling speakers .............................................................................14
3-2 BS-1030B/W wall-mount speaker .....................................................................................14
3-3 H-1 in-wall speaker............................................................................................................15
3-4 SC Series paging horns ......................................................................................................15
3-5 FB-100 subwoofer (left) and HB-1 in-wall subwoofer .....................................................16
5-1 Level change with distance................................................................................................22
5-2 Level change with power ...................................................................................................22
6-1 Ceiling speaker coverage area ...........................................................................................25
6-2 Speaker coverage with no overlap: hexagonal (left), square (right) ..................................26
6-3 Speaker coverage with minimum overlap: hexagonal (left), square (right) ......................26
6-4 Speaker coverage with edge-to-center overlap: hexagonal (left), square (right)...............27
6-5 Wall-mount speaker coverage area....................................................................................28
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TOA Electronics Speaker Guide
Welcome to the TOA Speaker Guide
TOA has long been recognized as a manufacturer of high-quality, flexible, and reliable amplifiers.
For over 75 years, we have also been an innovator in the design of high-performance speaker
systems for a wide range of applications. TOA has been at the forefront in the development of
specialized loudspeaker technologies for public spaces. TOA produced some of the first professional speaker systems that utilized dedicated electronic processing to optimize the speaker’s performance. TOA engineers presented the first AES papers on adaptive filter equalization
and the use of all-pass filters for flat-phase speaker tuning. Our test facilities include one of the
world’s largest anechoic chambers and state-of-the-art facilities for acoustics and reverberation
simulation. TOA was among the first to adopt the RASTI speaker intelligibility rating method
and we rigorously test our speakers using TEF 20 analyzers. TOA also assisted with the Japanese
translation of the classic text by Don and Carolyn Davis, Sound System Engineering, and has long
been a sponsor of Syn-Aud-Con sound system design seminars.
The purpose of this design guide is to provide sound contractors and systems integrators with
a convenient, easy-to-use reference to design small- and medium-sized TOA distributed speaker systems. The guide discusses the main parameters and trade-offs involved in designing distributed speaker systems and provides rules-of-thumb to help specify and implement them.
Disclaimer: This design guide does not cover all of the general concepts underlying sound
system design and installation, which would require several hundred pages. This guide is not
meant to replace the participation of an experienced consultant or engineer.
References: For more detailed information about sound system design principles, we recommend
the following two excellent books:
Sound System Engineering, Second Edition, Don and Carolyn Davis, 1975, 1987 by Howard Sams &
Co. ISBN: 0-672-21857-7
Handbook for Sound Engineers: Third Edition, Glen Ballou, Editor, 2001, Butterworth and Heinemann.
ISBN: 0-240-80454-6
Acknowledgements
Thanks to Steve Mate and John Murray in the TOA Product Support Group for their invaluable
support and contributions to this project. Thanks also to Don and Carolyn Davis for being guiding
lights to so many of us who work with sound and who always want the world to sound a little
(sometimes a lot) better.
David Menasco
Product Application Specialist
TOA Electronics, Inc.
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TOA Electronics Speaker Guide
Chapter 1: Getting Started: System Design
Steps
System design is essentially a process of answering the right questions in the right order. Answering the following questions will provide the basis of a sound design for your system. Not
included in the list is the question of project budget, which is always a guiding factor.
1. Where will the system be used?
Is it indoors or outdoors?
If indoors, is it highly reverberant?
How large is the space?
What mounting/installation options are available?
Answers to the following questions will guide the project and influence subsequent questions.
2. What will the system be used for?
Is it for music, speech, signaling tones, or a combination?
What level of fidelity, or sound quality, is required?
Is strong bass response important?
What level of speech intelligibility is required?
Defining the requirements of the system is critical to the success of the installation. Different sound
system applications and their requirements are discussed in Chapter 2: System Applications.
3. How loud must the system be?
How much noise is present in the listening environment?
Will the system be used for high-level foreground music?
Use an SPL meter to measure ambient noise levels on site during typical operating conditions.
An inexpensive SPL meter is available from Extech (http://www.extech.com). See Chapter 5:
Using Speaker Specifications for an overview of how to calculate the required sound pressure
and power levels, based on the background noise you measured or estimated.
4. What type of speakers are right for the job?
Will the job require ceiling, wall-mount, or other types of speakers?
Will subwoofers be needed to enhance the bass response?
Since the best speakers for one job may be amongst the worst for another job, proper matching
of the speaker to the installation is important. See Chapter 3: Speaker Types for a discussion of
the types of speakers most commonly used in distributed speaker systems, and the application
each is suited for.
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TOA Electronics Speaker Guide
5. How should the speakers be distributed throughout the space?
What layout pattern will be used (i.e., square or hexagonal)?
How far should speakers be spaced from each other?
It is often said that “location is everything.” Where speakers are concerned, this is often the
case. See Chapter 2: System Applications and Chapter 6: Layout and Spacing for Distributed
Speaker Systems for rules-of-thumb to establish the appropriate number and placement of
speakers.
6. How much power and what kind of wiring is required?
An amplifier with inadequate power can render a sound system unintelligible at normal operating
levels. Matching the amp(s) to the speaker(s)—and selecting the proper connecting cable—
are important ingredients of speaker system design. See Chapter 7: Amplifier Selection and
Appendix A: Wire Size Charts for this critical information.
7. Is equalization required?
In many cases, an equalizer can help balance the sound of a system. When microphones are
used, equalization may also improve gain before feedback. See page 20 for a brief discussion
of how equalizers function in distributed sound systems.
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TOA Electronics Speaker Guide
Chapter 2: System Applications
Paging
Paging systems communicate voice announcements throughout a building or area. Distributing
intelligible speech is the main requirement of a paging system. Consider the following points
when designing a system for paging:
• Speech energy is concentrated in the range 350 Hz – 5 kHz. System frequency response
should be smooth and consistent in this range.
• Speech intelligibility is most affected by system performance in the range 1–5 kHz.
Consistent coverage of the listening area is especially important in this frequency
range.
• People’s voices can vary significantly in loudness, sometimes leading to high peak
(short-term) demands on system power. Excessive distortion (due to overdriven amplifiers or speakers) can reduce intelligibility by masking the critical consonant sounds.
See Sensitivity Ratings and the Decibel on page 18, Determining Maximum Output:
Sensitivity and Power Handling on page 21, and Chapter 7: Amplifier Selection to
match your speakers and amplifiers to the application.
Additional intelligibility factors are discussed in Chapter 4: Audio Basics.
Speech Reinforcement
Sound systems that must amplify speech for extended periods of time (i.e., a meeting room or
a lecture hall) pose special challenges to the system designer. Consider the following points
when designing a speech reinforcement speaker system:
• It is important to avoid dead spots (quiet or dull-sounding areas within the listening
area) to maximize intelligibility and avoid feedback. Feedback occurs when the gain
is increased in an attempt to supply more volume to the dead areas.
• Using multiple mics to reinforce multiple speakers, as in a panel discussion, presents
a special challenge: Doubling the number of microphones reduces the system gain (relative volume) that can be reached before feedback by 3 dB.
• If more than four microphones are used, consider employing an automatic mixer, such
as the TOA AX-1000A, to help maximize system gain.
• The gain, or relative volume, that can be achieved depends on the relative positions of
the microphones, the loudspeakers, and the listeners, in combination with the acoustical
characteristics of the mics, loudspeakers, and room. Sound System Engineering is an
excellent reference for maximizing system gain (see page 9 for reference).
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TOA Electronics Speaker Guide System Applications
Background Music
Background music places different demands on a sound system than paging. Consider the following points when designing a background music system:
• Natural-sounding music reproduction requires a minimum frequency response range
of 100 Hz – 10 kHz that is wider than the basic speech range.
• Background music sources typically have limited dynamic range, and have a lower
peak volume requirement than foreground music or paging.
• Background music does not usually require the precise spectral balance and consistency of
coverage as speech; this allows wider speaker spacing in background music-only systems.
Foreground Music
Foreground music plays a more prominent role in the space’s primary function (i.e., music in
a bar or fitness center) than background music and is generally louder and more dynamic. The
special demands of foreground music include the following:
• At higher levels, the quality of the sound system is more noticeable. The frequency response range should be wider and distortion levels lower than a typical background
music system.
• Depending on the application and client taste, the bass response should extend down
to 60 Hz or lower, high frequency response to 16 kHz or higher.
• One or more subwoofers may be needed to provide additional bass output.
• The amplifier power and the sensitivity and power handling ratings of the speakers must
be adequate to reproduce the music’s peaks without distortion. This could mean using
five or even ten times more power than is used in a typical background music system.
See Power, Volume, and Decibels on page 17 for an overview of the relevant factors.
Voice/Music Combinations
Most installed sound systems are required to reproduce both speech and music. Therefore, they
must have both the smooth response and even coverage of a speech system and the wide frequency
range and continuous output capability of a music system. In a distributed speaker design,
this means using good quality speakers and relatively close spacing.
Presentation Audio
Sound for video and audio-visual presentations should be treated as a combination speech and
foreground music application. To reproduce sound effects (i.e., movie sound or attentiongetting AV presentations), amplifier power and speaker power handling should be adequate to
handle the highest program peaks.
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TOA Electronics Speaker Guide
Chapter 3: Speaker Types
There are four speaker types for distributed systems: ceiling, wall-mount, in-wall, and paging
horns. Subwoofers are also used in some systems to augment the bass. The following sections
discuss the characteristics and best uses for each type.
Ceiling Speakers
Figure 3-1 F-101C/M, F-121C/M ceiling speakers
Ceiling speakers distribute sound unobtrusively from a relatively low ceiling over a large floor
area. When installed with the proper spacing and sufficient amplifier power, a good quality
ceiling speaker provides uniform coverage and satisfactory frequency response for live speech
reinforcement and background music applications.
Wall-mount Speakers
Figure 3-2 BS-1030B/W wall-mount speaker
Wall-mount speakers, which are generally full-range, multi-way systems, are often well suited
for foreground music. They are also applicable if the ceiling is very high or is otherwise not
suitable for mounting speakers. Speakers may be mounted directly to the wall’s surface (i.e.,
TOA’s H series), or with a swivel bracket (F- and BS- series).
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TOA Electronics Speaker Guide Speaker Types
In-wall Speakers
Figure 3-3 H-1 in-wall speaker
Installing the speaker inside a wall is unobtrusive and deters theft. However, installation can be
costly and proper aiming and positioning are often problematic. The TOA H-1 in-wall speaker
overcomes this obstacle by using rotating speaker elements to aim sound where it is needed.
Proper spacing is important, especially for speech intelligibility.
Paging Horns
Figure 3-4 SC Series paging horns
Paging horns can achieve a higher SPL than ceiling or wall speakers, but have limited frequency
response, lower sound quality, and higher distortion levels. They are seldom used for music applications but are commonly used outdoors where long sound projection distances are needed.
They are also used in noisy environments where high sound levels are required for intelligible
messages (i.e., large public spaces, warehouses, and factories). When properly aimed and installed, their controlled coverage and reduced low frequency output increases the direct sound
level and reduces low-frequency masking, which are significant advantages in large rooms. The
TOA SC Series wide-range paging horns offer a compromise between high output levels and
sound quality that is preferred for outdoor music applications.
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TOA Electronics Speaker Guide Speaker Types
Subwoofers
Figure 3-5 FB-100 subwoofer (left) and HB-1 in-wall subwoofer
Distributed music systems are often faced with the challenges of delivering clear, high-fidelity
sound with enough power to overcome high ambient noise levels at an affordable price. Meeting these requirements has typically involved giving up good bass response because small
speakers cannot reproduce low frequencies at high levels. Since many contemporary musical
styles require powerful bass reproduction, adding a subwoofer is a cost-effective way to meet
this new demand.
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TOA Electronics Speaker Guide
Chapter 4: Audio Basics
The Decibel
The Bel, named in honor of Alexander Graham Bell, was originally defined as the loss of signal
level over one mile of telephone cable. A decibel is 1/10th of a Bel. Neither the Bel nor decibel
have an explicit level, but are specified as a logarithmic ratio.
Sound Pressure Level
Sound Pressure Level (SPL) is the acoustic pressure reference for the dB. The minimum
threshold of undamaged human hearing is considered to be 0 dB SPL. The threshold of pain
for undamaged human hearing is 120 dB SPL.
Power, Volume, and Decibels
Since the decibel is an expression of relative level change, it can be used to describe volume
levels in both the acoustical and electrical domains. 80 dB SPL refers to an acoustic volume
(loudness) level relative to the standard 0 dB reference. Changes in electrical power and voltage
can also be described in terms of the dB (see Sound System Engineering by Don and Carolyn
Davis for an in-depth discussion on the use of the decibel in sound system design). The following
rules of thumb will help properly utilize the decibel in speaker system design:
• A change of 2 dB SPL in overall volume is the smallest change perceptible to the
average listener.
• Increasing the volume by 3 dB requires doubling the amplifier power.
• Multiplying amplifier power by a factor of 10 increases SPL by 10 dB.
• Increasing the level by 10 dB SPL is perceived by a typical listener as doubling the volume.
• Voltage is not the same as power. Doubling voltage increases volume by 6 dB and multiplying voltage by 10 increases volume by 20 dB.
For the mathematically minded: The following equation converts power differences to volume
changes: level change in dB = 10 * log (P1/P2), where P1 and P2 are the power figures being
compared in Watts.
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TOA Electronics Speaker Guide Audio Basics
Sensitivity Ratings and the Decibel
A speaker’s sensitivity is the on-axis loudness (dB SPL) measured at a specific distance that
results from applying a specific amount of power (i.e., 1 W @ 1 m). The output level of the
speaker at different power levels and distances can be calculated from this figure. For example:
If a speaker’s sensitivity is rated at 96 dB SPL with a 1 W input measured at 1 m from the
speaker, then doubling the power to 2 W raises the output 3 dB to 99 dB SPL at 1 m. Doubling
the power again to 4 W produces 102 dB SPL. For a discussion and examples of how to use
sensitivity ratings, see Chapter 5: Using Speaker Specifications.
Attenuation over Distance: Inverse Square Law
The inverse square law describes how sound attenuates over distance. It states that volume
(SPL) decreases 6 dB each time the distance from the sound source is doubled. This is due to
the diffusion of sound radiating from the sound source over a spherical area. As the radius of a
sphere is doubled, its surface area quadruples, effectively dividing the acoustical power by
four. This is consistent with the discussion above of power, volume, and the decibel: dividing
the power by 2 results in a 3 dB decrease in volume; dividing by 4 results in a 6 dB decrease.
For the mathematically minded: The following equation converts a change in distance to a
change in level for a spherically radiating source: level change in dB = 20 * log (D1/D2), where
D1 is the original distance and D2 is the new distance.
Speech Intelligibility, Acoustics, and Psychoacoustics
Speech intelligibility refers to the degree a listener can understand spoken words in a particular
space. It is important to clearly hear and differentiate consonant sounds. The two basic parameters
affecting intelligibility are the smoothness of the system frequency response curve in the
speech range (about 350 Hz – 5 kHz) and the effective signal-to-noise ratio of the system (noise
can include echoes, reverberation, distortion, and even out-of-band signals such as excessive
bass). Good frequency response depends on selecting high-quality speaker components and
locating and aiming them correctly. The following sections on masking effects and reverberation
cover some often overlooked factors that affect achieving a good signal-to-noise ratio.
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