JBL 4425

Commentary

A speaker system that condenses the technology cultivated in 4430 into a medium size.

The low range is equipped with 2214H which is a 30 cm cone type woofer.
The diaphragm is made of pulp base coated with Aqua Plus, a unique coating reinforcement material, to increase rigidity and internal loss. The voice coil uses a 76 mm φ large-diameter copper ribbon edgewise wound voice coil.
The SFG (Symmetric Field Geometry) magnetic circuit is used for the magnetic circuit. This magnetic circuit reduces the second harmonic distortion by creating a symmetric magnetic field in the voice coil gap part. In addition, the flux stabilizing ring wound around the pole piece reduces the intermodulation distortion.

A horn type unit using bi-radial horn 2342 and driver 2416H is mounted in the high range.

Driver Unit 2416H is a driver unit that uses a titanium diaphragm with a diamond edge structure and a voice coil wound with pure aluminum wire edge width.
By using titanium which is a material of high rigidity and high durability, high specific elastic modulus and moderate internal loss are obtained, and wide range is realized by expanding piston motion. In addition, the edge pattern of diamond structure which is inspired by Japanese origami work is adopted in the edge part, and the structure combined with reinforcement rib resists high acceleration due to gravity and suppresses the generation of reverse resonance and divided vibration.
The voice coil is made by edgewise winding of pure aluminum ribbon wire, which is lightweight and excellent in electrical conductivity. By adopting aluminum ribbon wire with large cross-sectional area, the number of cutting lines of magnetic force increases, suppressing magnetic efficiency and improving conversion efficiency into sound. In addition, the pole piece is plated with copper in order to make the voice coil high-transient, smooth, and linear operating characteristics. The copper shortening plated on the pole piece reduces the DC resistance of the voice coil and improves damping. In addition, the impedance in the high-frequency range is controlled, making the response in the high-frequency range more excellent.

Based on computer analysis of various data, the Bi-Radial Horn 2342 is designed to maintain uniform thinking characteristics throughout the used band without loss of efficiency. This ensures constant directional characteristics of 100 ° horizontal x 100 ° vertical over a wide band. Moreover, it ensures an average directional pattern up to 1.2 kHz while suppressing the colorization characteristic of the horn.

Although it is 2-way, it is possible to control the power response of the mid and high frequency ranges independently.

The circuit configuration, elements, layout, wiring, etc. of the network section are carefully examined one by one to enhance the completeness of the circuit.

The enclosure uses a bass reflex system.

Model Rating

Method	2-Way, 2-Speaker, Bass Reflex System, Bookshelf Type
Units Used	For Low Band : 30 cm Cone Type (2214H) For High Range : Horn Type (2416H + 2342)
Frequency characteristic	40 Hz to 16 kHz ± 3 db
Directional (-6dB, 1.25 kHz to 16 kHz)	100 ゜ x100 ゜
Impedance	8 Ω
Output sound pressure level	91dB/W/m
Allowable input	200W (continuous program)
Peak input	1 kW (<10 ms)
Crossover frequency	1.2kHz
Enclosure volume	54 liters
External dimensions	Width 406x Height 635x Depth 375 mm
Weight	26kg