JBL 2391 (1982)

The JBL 2391 is a professional studio monitor horn, introduced in 1982. It's essentially the "pro" version of the JBL 2344 bi-radial horn found in consumer systems, and it was used in the classic JBL 4430 and 4435 studio monitors. It's a midrange/treble horn system. It was designed to run without a woofer, paired with separate low-frequency cabinets. In 2-way configurations, it was commonly matched with the JBL 2205A woofer.

The system uses the JBL 2421 compression driver on a radial horn, with a crossover network built into the horn assembly at 1.8 kHz. The cabinet is industrial, pro-style black with a foam grille. Rated sensitivity is a high 97 dB/W/m. Frequency response is 100 Hz-16 kHz (±2 dB) and impedance is 16 ohms. The power handling figure is a bit murky. A period review context refers to 200 watts program input, but that's not a formal spec sheet rating, so treat the number with some caution. A period review of the related 4320 system noted 60W continuous sinewave and 120W program power ratings Studio Sound (December 1972, p.47).

Documentation on the 2391 as a standalone item is thin. Most of what survives is tied to its role inside the 4430/4435 systems, where it did the midrange/treble work. No original price, dimensions, or weight are recorded in the research, and no direct owner reviews surfaced. Anyone hunting for one today should search parts listings under both "2391" and "4430", since that's where most of these horns actually lived.