JBL 375

Name: JBL 375
Brand: JBL

The JBL 375 is a compression driver, a high-frequency horn driver, and it helped build the company's reputation. Almost nothing about it survives in formal documentation. It sat at the heart of JBL's two most legendary loudspeaker systems of the 1950s, the Hartsfield and the Paragon. Audio (1958, p.29) ran JBL's own advertising for its "Signature" transducers, touting edge-wound aluminum ribbon voice coils and rigid cast frames. The 375 was built on that engineering philosophy.

According to Lansing Heritage forum threads, the 375 also appeared in the Olympus, S-8, C3 Cinema, and S5 systems, plus the C38 Cinema system and Ranger-Paragon. It's a 2-inch-throat driver. Enthusiasts are quick to point out that it's really more of a midrange driver than a true high-frequency unit, since it lacks the top-end extension of modern compression drivers. One forum user sums up the consensus: the 375 is a top-tier driver, but the compression driver world has moved on.

A reviewer describing the Hartsfield, which uses the 375, called it "the other horn-loaded loudspeaker that achieved near-legendary status in the 1950s," and noted its tremendous dynamic range.

Today, the 375 is sought after among vintage collectors and expensive on the used market. Great Plains Audio (GPA) sells a replacement diaphragm for roughly $200 - $250. That's a replacement part, not a complete driver.

Production years, original price, frequency response, power handling, impedance, dimensions, diaphragm material, magnet type, and crossover recommendations are missing. None of that is documented in the available record. Anyone with a pair and original literature can send it to the Archive.

Known specifications:

Type: Compression driver (high-frequency horn driver)
Throat size: 2 inches
Used in: Hartsfield, Paragon, Olympus, S-8, C3 Cinema, S5, C38 Cinema, Ranger-Paragon