JBL 4318

Commentary

This speaker system was developed with the aim of becoming the top of more than 4312 series control monitors by combining the technology of the flagship model 4348 of studio monitor with the state-of-the-art unit adopted in 4312D.

The low range is equipped with 2213 nd which is a 30 cm cone type woofer.
This unit is a renewal of 2213H, and by introducing the latest design method, improved response and low distortion have been realized.
Cone paper with Aqua Plus coating is used for the diaphragm.
The magnetic circuit uses JBL's unique N. D. D. (neodymium differential drive) system. The powerful neodymium ring magnet is sandwiched between two top plates, and two voice coils are arranged to drive the cone paper. The push pull drive of the cone paper by the dual pole piece and the dual voice coil creates accurate piston motion and realizes high linearity and sound quality without 歪巻.
A newly designed aluminum die cast integrally molded aerodynamic frame is adopted for the frame part, and driving loss is minimized by the 8 support columns firmly receiving the reaction caused by the front aftermovement of the cone paper. In addition, a unique bent gap cooling mechanism that forcibly air-cools the magnetic circuit by using the front aftermovement of the cone paper is adopted. By suppressing the temperature rise of the magnetic circuit, no heat drip occurs even at continuous high output and stable monitoring is possible.

The mid-range is equipped with 105H which is a 12.5 cm cone type mid-range.
The pulp cone used for the diaphragm is coated with high polymer on the surface to reduce distortion, and the magnetic circuit is equipped with 25 mm voice coil and large ferrite magnet to obtain excellent dynamic range.
The frame also uses an aluminum die-cast frame with a new basket design to minimize the effect of back pressure.

054Ti-1 which is a 2.5 cm hard dome type tweeter is installed in the high range.
A pure titanium diaphragm is used for the diaphragm. In addition, the sound energy balance and directivity are appropriately controlled by combining the high-density, high-rigidity SonoGlass short horn used for the 4348. The phase plug on the front of the unit adjusts the phase characteristics to achieve flatter and less distorted characteristics.
Neodymium magnet is used for the magnetic circuit.

In the network section, the woofer was connected in the full range in the previous 4312 series, but the 4318 uses a -6dB/oct low-pass filter to limit the range of the woofer, allowing a margin of playback capability to achieve a high response extended to the ultra-low frequency range.
High-quality parts such as large diameter gauge air-core coils and polypropylene film capacitors are used for the circuit. In addition, the low-frequency network circuit, which handles large current, and the delicate mid-high-frequency network circuit are separately arranged to eliminate the influence of electrical and magnetic interference on sound quality.

Equipped with a continuously variable attenuator volume that allows independent level adjustment for the middle and high ranges.

The enclosure uses a bass reflex system.
The unit layout adopts an inline layout in which the center of the unit is aligned on the center line of the baffle, and it is combined with a slant-type picture frame with enhanced diffraction effect to improve sound image localization and sound field reproducibility.
MDF material of 25 mm thickness is used for the front baffle, and the rigidity is strengthened by reinforcement and bracing of each part.
It also supports bi-wiring and passive bi-amplifier driving.

Model Rating

Method	3-Way, 3-Speaker, Bass reflex system, Bookshelf Type
Units, etc.	For Low Band : 30 cm Cone Type (2213 nd) For Middle Range : 12.5 cm Cone Type (105H) For High Range : Dome Type (054 ti)
Frequency characteristic	50 hz to 40 khz -6dB
Output sound pressure level	92dB/2.83V/m
Impedance	6 Ω
Allowable input	100W(RMS)
Crossover frequency	850 Hz, 4.7 kHz
External dimensions	Width 362x Height 597x Depth 289 mm (Including Grill)
Weight	19.5kg