JBL
4301B 2-way Broadcast Monitor, this
smallest monitor is designed primarily for the broadvast control room and edit
booth, and has achieved wide acceptance in home studios, remote recording and
quality controlareas. Smooth, wide range response and low distortion are
obtained from 200 mm (8 ") low frequency and 36 mm (1,4") high
frequency loudspeakers. A high frequency level control is provided on the front
baffle. Available in oiled walnut with dark blue grille.
The 4301B
shares its basic performance characteristics with all other JBL monitors -
exceptional clarity, wide dynamic range, solid bass and open high frequency
reproduction. The 4301B is efficient enough to produce a sound pressure level
of 98 dB in a typical broadcast booth of 1,8 m x 3,0 m x 2,4 m with an
amplifier delivering only 10 watts rms. The compact enclosure of the 4301B is
designed to fit the smaller spaces typical of broadcast control booths,
production studios or mobile recording , broadcast and film editing facilities.
Frequency
Dividing Network
Smooth
control of the component loudspeakers is achieved by a frequency dividing
network engineered and tested to complement the electrical and acoustical
character istics of the system. The dividing network is fitted with a
continuosly variable control that permits adjusting the relative level of the
high frequency direct radiator to suit listening preferences and room
conditions. The control does not affect the crossover frequency, not does it
limit the upper frequency response of the loudspeaker system.
High
Frequency Direct Radiator
The open,
crisp treble performance of the 4301B is the product of a 36 mm (1,4")
direct radiator designed for clarity, smoothness of response and power handling
capacity the 16 mm (5/8") copper voice coil is large in relation to cone
size for efficiency and transient reproduction with definition and accuracy,
yet the diameter of the cone and center dome has been kept small to obtain wide
dispersion. The magnetic assembly weighs 0,74 kg and generates a flux density
of 1,5 tesla.
The 4301B
utilizes a low frequency loudspeaker specifically engineered for a compact
enclosure without the compromises usually associated with smaller drivers. The
200 mm (8") loudspeaker exhibits unusually smooth frequency response, wide
dynamic range, superior transient reproduction and low distortion for a unit of
compact size. It features a precision die-cast aluminum frame for structural
integity under the most severe operating conditions. The 50 mm (2:) diameter
copper voice coil is suspended in a magnetic
field having a flux density of 0,85 tesla. The magnetic field is
generated by a 1,28 kg (3 lb) low-loss magnetic assembly. Mass and compliance
of the integrally stiffened cone have been carefully selected to optimize low
frequency bandwidth and definition while reducing distortion. As with all JBL
loudspeakers, this unit provides maximum power handling capacity and efficiency
consistent with the bandwidth expected of the device.
Enclosure
Size and
configuration of the 4301B enclosure have been carefully matched to the
acoustic characteristics of the component loudspeakers as well as the intended
use of the complete system. To achieve maximum strength and resistance to
vibration, all enclosure joints are hand fitted; all panels are constructed of
19 mm dense compressed stock. Acoustic damping material is applied to the
interior surfaces of the side and back panels to attenuate standing waves
within the enclosure. A ducted port extending through the baffle panel provides
proper acoustical loading of the low frequency loudspeaker. All components
mount directly to the baffle panel and are removable from the front of thr
enclosure. The four side panels are veneered with solid American black walnut,
hand rubbed to a rich, lustrous finish enhancing the natural beauty of
individual grain structure and color.
Specifications
Frequency
Response: 45 Hz - 15 kHz (±3 dB)
Power
Capacity: 15 W (Continuous Sine Wave)
Nominal
Impedance: 8 Ω
Power
Output: 88 dB SPL (measured at 3 m in a
room volume of 57 m³ with an
average absorption of 18,6 m² at ½ rated power input , -3 dB)
Sensitivity
(1 W at 1 m): 88 dB SPL
Distortion
(½ Power, 87 dB SPL/3 m. single
Frequency): 0,5% or less third harmonic
generation from 100 to 15,000 Hz
Crossover
Frequencies: 2,5 kHz
Polar
Response: no less than -6 dB at 90°
horizontal and vertical to 10 kHz
Enclosure
Volume: 30 litres
Dimensions (H x W x D): 483 x
292 x 306 mm (19" x 11½" x 12⅛")
Weight
(net): 12,7 kg (28 lbs)