JBL S4000

Little is documented about the JBL S4000. The record shows a big 4-way floor-standing loudspeaker, an acoustic suspension design with two 12-inch woofers, two 5-inch midrange drivers and two tweeters per cabinet, arranged as a mirror-imaged pair. By the specs it was a serious full-range system: 8-ohm nominal impedance, 93 dB sensitivity, frequency response rated from 32 Hz to 20 kHz, and recommended amplifier power of 10 to 250 watts. The crossover splits at 500 Hz, 3.5 kHz, and 5 kHz.

No production years, original price or weight figures have surfaced. There are no period reviews in the archive to draw on, and no driver model numbers are confirmed, so which JBL woofers and tweeters were used is unknown. What can be said is that this was a large, high-power-handling design in the classic JBL mold, built for people who wanted deep bass and high output from a sealed enclosure.

Type: 4-way floor-standing loudspeaker, acoustic suspension
Drivers per speaker: two 12" woofers, two 5" midranges, two tweeters
Impedance: 8 ohms
Sensitivity: 93 dB
Frequency response: 32 Hz – 20 kHz
Recommended power: 10–250 W
Crossover frequencies: 500 Hz, 3.5 kHz, 5 kHz
Arrangement: mirror-imaged pair