JBL CBT 100LA-1 User Manual
Quick Start Guide
for Sound System Designers
JBL CBT Series
Constant Beamwidth Technology™ Column Loudspeakers
(Note: Some models shown with the included grilles removed to illustrate driver composition.)
Rev A3
CBT Quick Start Guide 2
CONTENTS
Introduction .................................................................................................................... 3
• Understanding the Charts
o SPL Maps
o Frequency Response Charts
• Room Sizes Shown
Example #1 – Flat Listening Plane
CBT 50LA ..................................................................................................................... 4
CBT 100LA in Broad Setting ........................................................................................... 5
CBT 100LA in Narrow Setting ........................................................................................ 6
CBT 70J in Broad Setting ............................................................................................... 7
CBT 70J in Narrow Setting .............................................................................................. 8
CBT 70J+70JE in Broad Setting .................................................................................... 9
CBT 70J+70JE in Narrow Setting .................................................................................. 10
Example #2 – Highly Raked Seating
CBT 100LA in Broad Setting .......................................................................................... 11
CBT 70J in Broad Setting .............................................................................................. 12
CBT 70J+70JE in Broad Setting .................................................................................... 13
Example #3 – Gentle Rake with Balcony
CBT 100LA in Broad Setting .......................................................................................... 14
CBT 70J in Broad Setting .............................................................................................. 15
CBT 70J+70JE in Broad Setting .................................................................................... 16
Example #4 – Three-Tiered, Raked, Large Room
CBT 100LA in Broad Setting .......................................................................................... 17
CBT 70J in Broad Setting .............................................................................................. 18
CBT 70J+70JE in Broad Setting .................................................................................... 19
Design Conclusions ...................................................................................................... 20
• Vertical Coverage Setting vs. Installation Height
• Single vs. Multiple CBT Columns
o For Width
o For Depth
• Front Fill
• How Far Each CBT Model “Throws”
CBT Quick Start Guide 3
Excellent coverage of a wide variety of room types can be accomplished using JBL’s CBT Line Array Column
Loudspeakers. This guide shows some starting-point examples of placement, aiming and resulting
performance of the various CBT models in a variety of simplified sectional-view examples. There are 16
simulations in total, comprised of 4 examples of room-size / seating-plane scenarios.
These simulations allow you to compare the 4 CBT models (3 full-range models plus the CBT 70J+70JE
combination) and their settings as to:
• Overall SPL capability.
• Evenness of coverage.
• Consistency of SPL.
• Consistency of Frequency Response at various distances.
• How much sound goes outside the audience area.
Understanding the Charts:
SPL Map
All SPL maps use the same colors for the
same absolute levels, allowing SPL
comparison between various simulations.
SPL Range Arrows – The SPL range of the
microphone locations (at 4 kHz) is shown by
the arrows on the SPL chart to the right of
the SPL Mapping.
Frequency -- The frequency shown in the
SPL mapping in this guide is 4 kHz, which is
an especially challenging frequency at which to achieve acceptable coverage.
Power Drive Level & Air Absorption -- The SPL level represents the speaker as driven at full rated power
(in low-impedance, for those models that are selectable between low-impedance and 70V/100V taps).
Also note that air absorption, which in the real world reduces the high frequencies reaching the farther
areas of the room, IS included in these simulations, so this is representative of real-world SPL levels.
Frequency Response
At Multiple Points: The examples where
there are three mics represent Close, Mid,
and Far seating points. All are shown in
the SPEECH position and no external EQ
equalization is being utilized. Of course,
the speaker can be set in MUSIC (Flat)
position, and/or the frequency response
can be further EQ’d externally.
Speaker Models Shown -- In the first application example (Example #1 – Flat Listening Plane) ALL
speaker models and all settings are included. The subsequent examples, (Examples #2, #3 and #4) show only
those speakers that would be primary selections for that particular application.
Red = Close Seating
Blue = Mid Seating
Green = Far Seating
SPEECH Setting Raises
SPL in this region.
CBT
Room Sizes Shown – The first three examples (the first 13 simulations) are shown using the SAME room size
with a depth of 18 m (60 ft). This allows comparisons with only two variables – seating plane and speaker
type – being changed (one at a time), however CBT’s may be used in larger spaces.
Therefore, Example #4 (the last 3 simulations) shows a substantially larger room size with a depth of 38 m
(125 ft). Note that even though the graphs are shown as the same size on the page, the room size in the #4
example is a much larger room, illustrating that CBT’s can indeed be utilized in large rooms, depending on the
SPL requirements of the application.
CBT Quick Start Guide 4
Example #1 -- Flat Listening Plane
Description -- This is the most basic of rooms. All four CBT models are shown, as well as both
“Broad” and “Narrow” vertical coverage settings for those models that have the switchable
coverage capability (CBT 100LA & 70J)
Listening Plane = 1.2 m (4 ft) above the floor
Mic Placement = 6.1 m (20 ft, red icon), 10.7 m (35 ft, blue icon) and 16.8 m (55 ft, green icon)
CBT 50LA
Trim Height = 3.4 m (11 ft, Top of Speaker)
Down Tilt = 10°
SPL
(Full rated power, low-Z, SPEECH setting, 4 kHz, scale in feet):
Frequency Response (Full rated power, low-Z, speech setting, mic positions as designated above):
SPL Range
4 kHz
Example #1 -- Flat Listening Plane
CBT 100LA in Broad Setting
Trim Height = 4.9 m (16 ft, Top of Speaker)
Down Tilt = 15°
Vertical Coverage Setting = Broad
SPL
(Full rated power, low-Z, SPEECH setting, 4 kHz, scale in feet):
30
25
20
CBT Quick Start Guide 5
105
100
SPL Range
95
15
10
5
0
0 10203040506070
90
85
80
75
4 kHz
Frequency Response (Full rated power, low-Z, speech setting, mic positions as designated above):
110
100
90
80
70
20 50 100 200 500 1k 2k 5k 10k 20k
Example #1 -- Flat Listening Plane
CBT 100LA in Narrow Setting
Trim Height = 3.4 m (11 ft, Top of Speaker)
Down Tilt = 10°
Vertical Coverage Setting = Narrow
SPL
(Full rated power, low-Z, SPEECH setting, 4 kHz, scale in feet):
30
25
20
CBT Quick Start Guide 6
105
100
SPL Range
95
15
10
5
0
0 10203040506070
90
85
80
75
4 kHz
Frequency Response (Full rated power, low-Z, speech setting, mic positions as designated above):
Example #1 -- Flat Listening Plane
CBT 70J in Broad Setting
Trim Height = 4 m (13 ft, Top of Speaker)
Down Tilt = 5°
Vertical Coverage Setting = Broad
SPL
(Full rated power, low-Z, SPEECH setting, 4 kHz, scale in feet):
30
25
CBT Quick Start Guide 7
105
100
SPL Range
20
15
10
5
0
0 10203040506070
95
90
85
80
75
4 kHz
Frequency Response (Full rated power, low-Z, speech setting, mic positions as designated above):
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