JBL L150 (1979)

Name: JBL l150
Brand: JBL

A floor-standing 3-way passive radiator speaker system built for high-volume, live-performance sound.

Overview

The JBL L150 is a floor-standing loudspeaker released in 1979 by JBL (James B. Lansing Sound, Incorporated). It was designed to deliver high-volume sound like a live performance. It is a 3-way system with a passive radiator for extended low-frequency response. It belongs to JBL's consumer speaker lineup from the 1970s and 1980s, alongside the L65 Jubal, L112, and L300 Summit. The 3-way network has continuously variable level controls for the mid- and high-frequency ranges.

Specifications

Product type	3-way, 3-speaker, passive radiator system, floor type speaker
Low frequency unit	30 cm Cone Type (128H)
Mid-range unit	13 cm Cone Type (LE5-10)
High frequency unit	2.5 cm Dome Type (033)
Passive radiator	30 cm cone type passive radiator (PR300)
Network	Dedicated 3-way network
Allowable input	200W (continuous program)
Impedance	8 Ω
Crossover frequency	1 kHz, 4 kHz
Output sound pressure level	88 db (New JIS)
External dimensions	Width 432 x Height 1,054 x Depth 330 mm
Weight	36.4kg
Original price (Japan)	210,000 ¥ (1 unit, released in 1979)

Design

The woofer is a 30 cm cone-type 128H with a 4.7 kg ferrite magnetic circuit. The circuit is based on JBL's symmetrical field geometry (SFG), which is meant to balance the magnetic flux and cut second harmonic distortion through a Faraday loop. The voice coil is 7.5 cm in diameter, made of copper ribbon wound edgewise, and the diaphragm is hard cone paper. A newly developed 30 cm passive radiator (PR300) extends the low-frequency response. The mid-range driver (LE5-10) has a 13 cm hard cone, a 2.2 cm copper ribbon voice coil and a 14,000 Gauss magnetic circuit. It sits in its own sub-chamber to isolate rear wave interference. The 2.5 cm dome tweeter (033) has a resin-impregnated linen diaphragm and an aluminum ribbon voice coil in a 14,000 Gauss magnetic circuit. The crossover has phase and impedance correction circuits on a printed board, plus the adjustable mid- and high-frequency level controls. The enclosure is 1.9 cm thick rigid particle board, and the net grill comes in camel, red, or brown.

Context

The JBL L150 is part of JBL's consumer speaker lineup from the 1970s and 1980s. It shares design ideas and component technology with contemporary models such as the L65 Jubal, L112, and L300 Summit. It was developed for high-volume sound reproduction like a live performance, with an emphasis on dynamic range and clarity.