Released in 1979 4311B : ¥ 154,000 (1 unit, around 1980) ¥ 135000 (1 unit, around 1981)
This is the third generation speaker system of the 4311 used by studios and broadcasting stations around the world.
Equipped with 30 cm cone type woofer 2213H in the low range. This unit uses white cone paper coated with JBL's original white dumping agent, a voice coil wound around the edge of a 7.5 cm diameter copper ribbon wire, and a 4.7 kg low-distortion magnetic circuit resonance frequency of 22 Hz.
13 cm cone type Skoka LE5-10 is mounted in the middle area. By driving hard cone paper with a 15,000 Gauss magnetic circuit and 2.2 cm diameter voice coil, smooth frequency characteristics and wide directional characteristics are obtained.
The 3.6 cm cone type tweeter LE25-2 is mounted in the high range.
There are separate level controls for the mid and high frequencies. This level control is designed so that it can be adjusted even if the front grill is equipped.
The front baffle is designed for hanging use in small studios and adjustment rooms, and adopts a unit layout with a squaker and a tweeter at the lower part.
There were 2 types of exterior, gray finish and walnut finish.
