JBL 4307

Commentary

This speaker system adopts the appearance and system design that inherited the tradition of JBL Studio Monitor.

The 4307 was designed as a middle-sized monitor between the control monitor series equipped with 12 inch (30 cm) diameter woofer represented by the 4312D/4318 and the compact monitor equipped with 8 inch (20 cm) diameter or smaller diameter woofer with 4305H at the top.

A 25 cm cone type woofer is installed in the low range.
The diaphragm is made of unbleached, uncolored pure pulp white corn with natural sounding characteristics. In addition, the diaphragm is equipped with a low-distortion magnetic circuit, a vibration system with excellent transient characteristics, and a frame structure with excellent strength and rigidity to provide excellent response and clear sound quality.

The mid-range is equipped with a 12.5 cm cone type mid-range that was also adopted in the 4312D/4318.
Pure pulp cone is used for the diaphragm, and the generation of strain is suppressed by coating the surfaces with high polymer. In addition, the smooth response of the diaphragm is made possible by double pleat Cross Edge.
A powerful magnetic circuit with a large magnet is used for the magnetic circuit.

A 3.8 cm ring-type tweeter is installed in the high range in combination with a horn.
In this unit, the diaphragm is provided with tangential ribs, and the driving force from the voice coil is uniformly transmitted to the entire diaphragm to obtain the accurate piston motion of the diaphragm. In addition, the diaphragm is provided with a dual-layer structure consisting of a special polymer material laminated with damping film to achieve high-frequency playback with less distortion.
By combining this tweeter unit with an aluminum die-cast outer horn, we can optimize the directional characteristics and secure the reproduction energy up to the crossover range, while suppressing unnecessary vibrations of the tweeter that affect the reproduction stage.

Air-core coils and high-quality film capacitors are used in the network section.
Equipped with a continuously variable attenuator volume that can adjust the output levels of the mid and high ranges independently.

The enclosure uses a bass reflex system, and by installing two bass reflex ports, low-frequency playback exceeding the cabinet size is realized.
Inline layout is adopted for the unit layout, and by aligning the center of all units on the center axis of the front baffle, sound image localization and sound field reproducibility are improved. The front baffle is finished with monitor blue, which is the proof of studio monitor.

Model Rating

Method	3-Way, 3-Speaker, Bass reflex system, Bookshelf Type
Units Used	For low band : 25 cm cone type For Medium Range : 12.5 cm Cone Type For High Range : Horn Type (3.8 cm Ring Tweeter + Horn)
Frequency characteristic	45 Hz to 45 kHz
Allowable input	150W(music)
Impedance	6 Ω
Output sound pressure level	91dB/2.83V/m
Crossover frequency	1.5 kHz, 6.5 kHz
External dimensions	Width 328x Height 545x Depth 300 mm (Depth includes grill)
Weight	16.6 kg (including grill)