JBL 4845

The JBL 4845 is a professional cinema loudspeaker. It is a three-way, bass-reflex screen system made to sit behind the perforated screen in a movie theater. It's big: 668 mm square and 584 mm deep, and it weighs 68 kg (150 lb). The drivers are a 460 mm (18 in) woofer, a 250 mm (10 in) midrange, and a 38 mm (1.5 in) high-frequency driver. The top end is horn-loaded, and a built-in crossover network splits the frequencies.

The 4845 is rated for 30 Hz to 17 kHz. System sensitivity is 96 dB SPL at 1 watt, 1 meter, and nominal impedance is 8 ohms. JBL recommends 1000W of input power, with a peak capacity of 4000W (continuous program). Those are numbers for large rooms and high output, not living rooms. It was part of the professional lineup documented on jblpro.com. A period piece in Mix Magazine (June 1989, p.109) described the 4845 as a single 18-inch subwoofer offering low-end reinforcement in professional systems, and placed it alongside the dual-18 4842.

Beyond its intended cinema role, the documented record is thin. No production years, original price, or crossover frequency have surfaced in the available research, and no owner reviews or common-problem reports exist in the archive. What’s clear is that the 4845 was a serious, high-SPL tool for theatrical sound — a purpose-built workhorse rather than a consumer curiosity.

Type: Three-way, bass-reflex cinema screen speaker, horn-loaded HF
Drivers: 460 mm (18 in) LF · 250 mm (10 in) MF · 38 mm (1.5 in) HF
Frequency range: 30 Hz – 17 kHz
Sensitivity: 96 dB SPL / 1W @ 1m
Impedance: 8 ohms
Power: 1000W recommended input · 4000W peak program
Dimensions: 668 × 668 × 584 mm (26.3 × 26.3 × 23 in)
Weight: 68 kg (150 lb)