The Model 2231 low frequency
accurate,
solid low-frequency
free air resonance
exceptional
enclosure
deep bass response
volume.
exceptional.
Compared
constructed
efficiency
and requires
tdother
very little
loudspeakers
response
of mechanical
enclosure,
and transient
ability to handle sustained
danger
The 2231 has a low-loss
with
is unusually
pounds
magnettc
(5 9 kg), consrstrng
structure
top plate The pole piece and magnetic
constructed
having
ponent
linear,
amount
IS
that weighs
of a large Alnrco V magnet
of high conductivity
precisely
machined
of magnetic
energy
13
and
return casting are
Iron alloy and each comto concentrate
a maximum
in the voice co11gap
only *2 dB from 40 Hz to 800 Hz. When housed
in a properly
-
provides
Designed
below the range of hearing, the 2231 has
similar sensitivity, its frequency
varying
loudspeaker
reproductron
the 2231 will exhibit
response
as well as the
signals at high power levels without
damage
or excessive
distortion.
The combination
rugged
edgewound
achieve
of this powerful
cone assembly
copper
sensitivity
structure,
a
ribbon voice co11enable the 2231 to
100 W continuous
exceptional
magnetic
and 4-inch (100 mm) diameter
program
and smooth
power capacity,
acoustic
output
Architectural
Specifications
The low frequency
transducer
shall have a nomrnal diameter
of 15 Inches (380 mm), overall depth not greater than 5%
(145 mm), and weigh at least 16% pounds
Inches
frame shall be of cast alumrnum
the magnetic
assembly
(75 kg) The
to resist deformation,
shall use Alnico V encased
cast iron return crrcurt for maximum
efficiency
and
In a heavy
and suppres-
sion of stray fields The voice coil shall be 4 inches (100 mm)
In diameter
operating
and shall be made of edgewound
In a magnetrc
copper
ribbon
field of not less than 1 2 T
Performance
specrfrcatlons
be as follows
Measured
of a typical productron
unit shall
sensrtlvrty (SPL, 1 W at 1 m, averaged
from 100 Hz to 500 Hz) shall be at least 93 dl3 SPL on axis
As an indication
of electromechanical
converslon
efficiency,
the BI factor shall be at least 21 Tarn
Usable frequency
response
On-axis response,
measured
shall extend from 25 Hz to 2 kHz.
at a distance
or more under free field conditions,
40 Hz to 800 Hz. Nominal
power capacity
shall be 80. Rated
shall be the JBL Model 2231. Other
will be considered
that submitted
laboratory
impedance
shall be at least 100 W typical program
material. The transducer
loudspeakers
of 6.6 feet (2 m)
shall be *2 dB from
for equivalency
data from a recognized
provided
independent
verify that the above performance
test
specifications
are met.
JBL continually
materials
~ng products
reason
engages
productIon
wlthout
any current
descrlptlon
speclflcatlons
notlce
and
related
design
as a routine
JBL product
but IS always
unless
in research
methods
may
warranted
otherwIse
to product
refinements
expression
differ
to equal
improvement
New
are Introduced
Into ewt-
of that
un some
or exceed
respect
philosophy
from
the original
Forthis
Its publIshed
design
stated
JBL Professional
Products
are not Intended
for household
use
--
Professional
James B. Lansing Sound,
Division
Inc., 8500 Balboa Boulevard,
Northridge,
California
91329