Bose FreeSpace 3 Guide

DESIGN GUIDE
FreeSpace®3 Flush System
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1
Overview
This application note covers the basic concepts for
the use of the FreeSpace 3 system in business music
applications.
The FreeSpace 3 system is ideally suited to back-
ground and foreground music applications with
ceiling heights between 8 and 16ft (2.4 to 5m).
The 2.25 inch driver used in the FreeSpace 3 system
provides more consistent coverage in low ceiling
applications, compared to other loudspeakers, and
the Acoustimass®bass module provides deep, rich
bass that appears to fill the room. The FreeSpace
3 system is compatible with 70V, 100V and 8 Ohm
amplifiers, and is capable of delivering up to 95dBSPL
in a typical application with a 12ft (3.5m), ceiling
height.
All system designs begin with a set of requirements.
The system requirements can be as simple as “it has
to sound great,” or as detailed as “it must have an
output level of 100 dBSPL”. In either case, the chal-
lenge is to gather the right set of requirements and
convert them into a set of design criteria to use in
creating your design.
The three key requirements that you need to identi-
fy in order to deliver the right business music sound
system are:
Loudness What sound pressure level is required
for this application?
Response What bandwidth is required for the
type of program material that will be used?
CoveRage How consistent must the sound be
across the entire coverage area?
Prod uct Specifications
Frequency Range 50Hz – 16kHz ± 3dB
Long Term Power Handling 100 watts continuous (8 Ohm)
Sensitivity 82 dB-SPL @ 1W/1m (pink noise)
Impedance 6 Ohm
Maximum Acoustic Output 102 dB-SPL @ 1m (pink noise)
Dispersion 170° Conical (Satellite)
Omni-directional (bass)
Each of these requirements can be easily converted
into a specification that we can use to create our
system design. If we understand the customer’s
needs in these three areas, we can deliver a design
that will, at a minimum, meet their needs, and at
best exceed their expectations.
For the purposes of this application note, we will
assume that you are familiar with the system
requirements for a business music system and are
ready to focus on the creation of a loudspeaker
layout using the FreeSpace 3 system.
Design Guidelines
When creating a design that uses the FreeSpace 3
system, you should consider the following:
•RecommendedmountingheightforSatellitesis
between 8 and 16ft (2.4 and 4.8m).
•OneSatelliteshouldalwaysbeplacednearthe
bass module to further reduce localization.
•Donotplacebassmodulesalongthecenterline
of the room; offset bass modules from the center
line using a staggered layout.
•MaximumSPLforatypicalapplicationisbetween
85 and 90dBSPL.
•Alwaysadd25%headroomtoyouramplifierto
accommodate various types of program material.

Design Worksheet
Use the following worksheet to create a design using the FreeSpace 3 surface mounted loudspeakers.
step 1 Using the graph paper on the last page, create a sketch or drawing of the room.
step 2 Confirm that the FreeSpace 3 System will meet your loudness requirement.
A. On the chart below, locate the loudspeaker mounting height for this design.
B. Draw a line down to the desired maximum SPL.
C. Draw a horizontal line across the chart at your desired SPL level.
D. All of the loudspeakers listed below the line will meet your loudness requirement.
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FreeSpace®3 Flush System
DESIGN GUIDE
note: If the loudspeaker that meets your
response and loudness requirement does
not meet your mounting needs select one
that provides more bandwidth, and also
meets your mounting needs.
step 3 ConfirmthattheFreeSpace3SystemwillmeetyourResponseRequirement.
m 2.4 3.0 3.6 4.2 4.8 5.5 6.1 6.7 7.3 8.0 10.0
ft 8 10 12 14 16 18 20 22 24 26 32
DS 16S / SE 90 89 89 88 87 86 85
360P-II 94 93 92 90 89 88 87
FreeSpace 3 96 95 95 94 93
Model 32SE 96 96 95 94 93 92 91 90
DS 100SE 98 97 97 96 95 94 93 92 92 91 89
FreeSpace 203 98 97 97 96 95
DS 16F 99 97 94 91 90 88 87
102F 105 100 98 95 94 92 91 90 89 88
DS 100F 107 103 102 99 98 96 95 94 93 92 89
Model 32 107 103 100 97 96 94 93 92 91 90
dBSPL
Loudspeaker
Mounting
Height
Maximum Continuous Output Level
L O U D S P E A K E R
Vocal Range Full Range Extended Range
DS 16S & SE 203 FreeSpace 3
DS 16F 360P-II
Model 32 DS 100SE Any vocal range loud-
speaker combined with
a FreeSpace 3 bass
module.
Model 32SE DS 100F
102F

DESIGN GUIDE
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FreeSpace®3 Flush System
step 5 Using your sketch of the room, create a Bass Loudspeaker Layout with the correct number of
bassmodulestomeetyourCoverageRequirement.
A. Determine the quantity of bass
modules required for your system layout.
Coverage Bass Required
Premium Total Satellites /2
Standard Total Satellites /4
B. Use the spacing guidelines below, determine the minimum
spacing between two or more FreeSpace 3 bass modules.
Bass Module
Spacing
FreeSpace 3 Bass Module Mounting Height
8ft | 2.5m 10ft | 3m 12ft | 3.5m 16ft | 4.8m
Min Spacing (ft)
20 25 30 35
Min Spacing (m)
6 7.5 9 11
step 4 Using your sketch of the room, create a layout with the Loudspeaker Spacing that meets your
CoverageRequirement.
Loudspeaker
Floor
Loudspeaker Throw Distance
(Loudspeaker Mounting Height - Listener Height)
Listener Height
Loudspeaker Mounting Height
Seated - 3ft | 1m
Standing - 5ft | 1.5m
A. Calculate the
Loudspeaker
Throw.
C. Place the first
loudspeaker
at ½ the
Loudspeaker
Spacing
distance from
any corner of
the room.
½
Loudspeaker
Spacing
½
Loudspeaker
Spacing
B. Calculate the Loudspeaker Spacing distance by multiplying
the Loudspeaker Throw Distance by the Coverage Multiplier.
Coverage Multiplier
Premium 2.0
Standard 2.5
Loudspeaker Throw Distance x Coverage Multiplier = Loudspeaker Spacing
(Loudspeaker Throw
Distance)
(Coverage Multiplier) (Loudspeaker Spacing)
x=
D. Remaining loud-
speakers are
arranged on a
square grid
pattern using
the Loudspeaker
Spacing
distance.
Loudspeaker
Spacing
Loudspeaker
Spacing
step 6 Calculate the required amplifier size. Use the Tap Chart at below to determine which loudspeaker
tap is required for this design.
m2.4 3.03.6 4.24.8
ft 810121416
25 87 86 86 85 84
50 90 89 89 88 87
1009392929190
2009695959493
dBSPL
FreeSpace 3 Flush System Tap Chart
T
A
P
Mount
Height
A. Locate the loudspeaker mounting height for this design.
B. Draw a line down to the desired maximum SPL.
C. Draw horizontally across the chart to read the required loudspeaker tap.
D. Calculate the required amplifier power:
Amplifier SizePower Required
=
x 1.25
E. Calculate the required amplifier size:
Number of Loudspeakers Required Loudspeaker Tap Power Required
x =
Headroom

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Project Name:___________________________________________________ Contact: ___________________________________ Date:_______________
DESIGN GUIDE
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FreeSpace®3 Flush System
All information subject to change without notice.
©2007 Bose Corporation.
Bose and FreeSpace are registered trademarks of Bose Corporation.
Other marks are the property of their owners.
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