Index
Professional Division Warranty 1
Specifications 1
The 4311 Control Monitor 2
Test Parameters 3
Installation 4
Maintenance 5
Additional Information 5
Professional Division Warranty
Every JBL Professional Series transducer is guaranteed
against defects in material and workmanship for a period of
five years. JBL electronic products are warranted for a
period of two years. JBL will replace defective parts and
make necessary repairs under this warranty if our exam-
ination reveals evidence of faulty workmanship or material.
The warranty does not cover damage caused by misuse,
accident or neglect. JBL retains the exclusive right to make
such determination on the basis of factory inspection.
Moreover, because we believe that a fine loudspeaker,
like a fine musical instrument, should never wear out, we
will repair any JBL transducer free of charge without time
limitation if factory inspection discloses evidence of an
original manufacturing defect.
If it is impractical to return the product to the factory,
please write JBL describing the difficulty or malfunction.
JBL may, at its option, establish alternative repair proce-
dures or furnish replacement parts as appropriate.
Products returned to the factory must be shipped prepaid
and will not be accepted unless written authorization has
first been obtained.
The warranty on JBL products shall remain valid only
if repairs are performed by JBL or under its authorized
procedures, and provided that the serial number on the
unit has not been defaced or removed.
Power Capacity'
75 Watts continuous program
Crossover Frequencies
1500 and 6000 Hz
Nominal Impedance
8 ohms
High Frequency Dispersion 90° horizontal and vertical
Frequency Response
45-15,000 Hz ± 3 d B
Sensitivity
2
42 d B at 30 teet with a 1-mW input
averaged 500 to 2500 Hz,
with controls set for flattest
response
81 d B at 10 feet with a 1-Watt input,
averaged 500 to 2500 Hz, with
controls set for flattest response
Low Frequency Loudspeaker
Nominal Diameter
12 inches 30 c m
Voice Coil
3-inch (7.6 c m ) edgewound copper
ribbon
Magnetic Assembly Weight 6.75 pounds 3.1 kg
Flux Density
10,400 gauss
Sensitivity
3
42 d B
Midrange Transducer
Nominal Diameter
5 inches 13 c m
Voice Coil
%-inch (2.2 c m ) copper
Magnetic Assembly Weight 2.75 pounds 1.2 kg
Flux Density
16,500 gauss
Sensitivity
(averaged 1-3 kHz)
46 d B
High Frequency Direct Radiator
Nominal Diameter
1.4 inches 3.6 c m
Voice Coil
%-inch (1.6 c m ) copper
Magnetic Assembly Weight 1.6 pounds 0.7 kg
Flux Density
15,000 gauss
Sensitivity
(averaged above 2 kHz)
47 dB
Finish
Textured gray or oiled walnut with
black fabric grille
Dimensions
2 3 V x 1 4 V x 1 1 V deep
6 0 x 3 6 x 3 0 c m deep
Net Weight
42 lbs 19 kg
Shipping Weight
49 lbs 22 kg
'See Installation section for amplifier power recommendation,
2
N o t e : Unlike many "theatre type" loudspeaker systems that exhibita rise in the
midrange region, the 4311 is a true monitor providing substantially the same
sensitivity through the full range of audible frequencies. Measured sensitivity
below 500 Hz or above 2000 Hz may be considerably greater than that of
other systems with higher EIA sensitivity ratings.
3
Since the major portion of the energy reproduced by the low frequency loud-
speaker lies below 800 Hz, this specification has been developed by using a
test signal warbled from 100 to 500 Hz, rather than the conventional 1-kHz
sine wave test signal on which the EIA sensitivity is based.
Specifications