The JBL 4331 is a 2-way speaker system designed to deliver high-quality sound and performance. Released in 1976, it improves upon earlier models like the 4320 and 4331. The system features a 38 cm cone woofer (model 2231A) for low-frequency sounds and a combination of a horn-type unit with an acoustic lens (2308), an exponential horn (2312), and a driver (2420) for high-frequency reproduction. It employs a bass reflex enclosure design to enhance low-end performance. The speaker can be configured for both 2-channel multi-amp drive and standard use, thanks to a switch located at the rear. Additionally, users have the flexibility to mount the acoustic lens either vertically or horizontally to suit their listening environment. The construction is robust, featuring iron reinforcing metal fittings that allow for suspension if desired. The 4331 has two aesthetic variations: the 4331A with a gray finish and black grill, and the 4331 AWX with a walnut finish and blue grill. The speaker's specifications include a frequency response range from 35 Hz to 15 kHz with a crossover frequency set at 800 Hz, a weight of 57 kg, and external dimensions of 619 mm in width, 778 mm in height, and 497 mm in depth.
