JBL 4612B (circa 1984)

A 20.4 kg wedge of 19mm plywood with two eight-inch cones and a bi-radial horn. It's the smallest full-range box JBL's Cabaret line ever shipped, and one of the most useful.

Overview

Pick up a 4612B and the first thing you notice is the coating. The whole enclosure is wrapped in polyurethane over 19mm multi-layer plywood, which means JBL built it to survive being thrown in and out of a van. The corner guards and the carry handle say the same thing. This is not a living-room speaker that happens to be portable. It's a working box that sounds good enough that people took it home anyway.

The topology is where the 4612B gets interesting, and where the documentation gets slippery. JBL's own reference chart lists the model as a two-way using a pair of 2118J drivers in the low band and a single 2404H-1 in the high. The same chart's note on the 2404H-1 confirms it's the Cabaret variant of the 2404 tweeter, running the D8R075 replacement diaphragm. That's a 100° x 100° bi-radial horn tweeter, which explains the wide, controlled dispersion JBL's sales literature bragged about. Independent spec listings describe the same box as a "2-way, 3-speaker, bass reflex system" with two 20 cm cone woofers (2118H) and a 2404H horn on top. Enthusiasts who've studied the crossover argue it's really a 2.5-way in a wider cabinet. Treat the exact topology as unsettled. The driver complement is not.

JBL's own brochure copy, quoted in a Reverb listing, called the 4612B "the most compact of our full range Cabaret Series systems" and pitched it as "ideal for any sound reinforcement application that requires a blend of outstanding performance and maximum portability." That's marketing. The compactness claim checks out against the dimensions, and the portability claim checks out against the handle.

Key Features

Dual 20cm 2118J Woofers in a 28-Litre Vented Box

Two eight-inch cone drivers in a bass reflex enclosure of roughly 28 litres is a deliberate trade. You give up the last octave of low end and get back efficiency and punch. Published frequency response is 60 Hz to 21.5 kHz at -10 dB. Note the tolerance, because -10 dB is a very generous way to describe a cutoff, and one forum analysis puts the vented box's actual low cutoff nearer 80 Hz. Either way, nobody should buy a 4612B expecting subwoofer depth. The pair of cones delivers midbass slam and headroom, and the 97 dB/W/m sensitivity figure means a modest amplifier gets loud fast.

2404H Bi-Radial Horn Tweeter

The high end comes from JBL's 2404H, a horn-loaded tweeter with 100° x 100° dispersion in both planes. That pattern is why these boxes work as front fills and as flown cabinets in cluster arrays. The sound spreads wide and stays controlled rather than beaming at the back row. The crossover sits at 3 kHz, and there's a level control for the high-frequency band on the cabinet. That's the most practical feature on the thing, since rooms vary and being able to trim the horn without touching the console is worth real money on a gig.

19mm Plywood Enclosure with Polyurethane Coating

The cabinet is 19mm rigid multi-layer plywood, coated across its entire surface in polyurethane for strength and road resistance. Corner guards protect the edges when boxes get stacked, and the handle is there for transport. External dimensions run 546 x 497 x 267 mm at 20.4 kg. That's heavy enough to feel substantial, light enough for one person to move. The input is an M6 phone jack, which dates the design to its era and will be the first thing a modern user has to adapt.

Optional Stand and Front Cover

JBL sold the accessories separately, and collectors chasing complete examples should know what to look for: a dedicated front cover (4612 cvr, ¥20,000) and a speaker stand (MT4612, ¥35,000). The 1989 JBL component listing still carries the MT4612 tripod stand as a live part, and also lists a 4612CVR hard cover. So the accessories stayed in the catalog well after the speaker itself. A 4612B with its original cover and stand is a more complete package than a bare cabinet.

Historical Context

The 4612B belongs to JBL's Cabaret Series, described in period documentation as a line developed specifically for sound reinforcement. Audio-database places the model around 1984 at ¥230,000 per unit. Earlier research on this model concluded no original price had surfaced, so this figure is new. It's single-sourced and should be treated as approximate.

Its working life is better documented than its birth. A seller recalling corporate production work describes the 4612B as one of the go-to cabinets of the era, used alone or as hi-packs in a bi-amped rig. Another owner remembers hearing four cabinets flown from a ceiling alongside two bass bins, and came away impressed with how the room tuned up. Mix (June 1988, p.170) lists JBL monitors among the standard monitor rigs in professional studio inventories of the period.

Collectibility & Value

These are working speakers, not display pieces, and the market treats them that way. A Reverb listing in mint condition was asking $459 after a $20 drop from $479, described as vintage, smoke-free, and one-owner. eBay listings style them as "rare vintage," which is seller language rather than a market verdict. The 4612Bs trade on utility. Buyers want them for rehearsal rooms, small PA rigs, and front-fill duty, and the price reflects what a functional pair is worth to someone with a use for it rather than any collector premium.

Maintenance information is thin. The one concrete technical note in the record concerns tweeter substitution. A forum user asking whether standard 2404H tweeters could go into a 4612B without crossover changes was told the tech sheet specifies the 2404H-1 variant. That means the two are not automatically interchangeable, and the crossover is matched to the -1. Anyone buying a pair with swapped tweeters should factor that in. No documented failure patterns, capacitor issues, or spare-parts shortages have surfaced in the available material. That doesn't make the speakers trouble-free. The record is silent.