JBL 4311B (1979)

Name: JBL 4311B
Brand: JBL

That punchy, no-nonsense studio sound - raw, revealing, and built like a tank.

Overview

The JBL 4311B is the third generation of a studio monitor lineage that became the backbone of professional audio in its day. It is a 3-way, bass-reflex bookshelf speaker, built for broadcast and recording studios. It was never meant to coddle your ears. It was designed to tell you exactly what was on the tape, warts and all. Released in 1979, the 4311B refined its predecessors with a focus on neutrality, durability, and practicality. It was a favorite in control rooms and among audiophiles who wanted unfiltered truth from their systems.

JBL built the 4311B as a professional 3-way studio monitor loudspeaker system to endure daily abuse and still deliver consistent, high-fidelity output. It was designed for recording, broadcast, and film, where accuracy trumps flattery. It doesn't smooth over bad recordings. It makes you notice them, and that's why engineers and critical listeners loved it. The 4311B is a no-frills, high-energy speaker that few of its era can match.

Specifications

Manufacturer	JBL
Type	3-Way, 3-Speaker, Bass reflex system, Bookshelf Type
Frequency Response	45 Hz to 15 kHz ± 3 dB
Dispersion	90°
Impedance	8 Ω
Sensitivity	91 dB (1W/1m)
Power Handling	40W(RMS) / 75W(Peak)
Crossover Frequencies	1.5 kHz, 6 kHz
Enclosure Volume	40L
Dimensions (W × H × D)	362 × 597 × 298 mm / 14.25 × 23.5 × 11.75 inch
Weight	21 kg / 46 lbs
Woofer	300 mm (12") cone type (2213H)
Midrange	130 mm (5") cone type (LE5-10)
Tweeter	36 mm (1.4") cone type (LE25-2)
Enclosure Type	Bass reflex (studio monitor)
Inputs	Two 1/4" phone jack inputs
Grille	Black fabric (removable)
Finish	Walnut or Gray

Key Features

Time-aligned driver layout with practical studio ergonomics

The front baffle of the 4311B was designed for real-world studio use. It's built to be hung in small studios or adjustment rooms, with the midrange and tweeter positioned lower on the baffle. This layout improves vertical dispersion and reduces floor bounce when wall-mounted, which helps engineers working in tight spaces. The separate level controls (L-pads) for mid and high frequencies are accessible even with the front grill in place. You can tweak the voicing without exposing the drivers.

Brute-force driver engineering

The 12" 2213H woofer uses a white cellulose cone, a 7.5 cm voice coil, and a low resonance frequency. That gives deep, controlled bass with minimal distortion. It's industrial-grade hardware meant to handle long sessions at high SPLs. The 5" LE5-10 midrange driver pairs a hard cellulose cone with a robust magnetic circuit, for crisp, distortion-free vocals and instruments. Up top, the 1.4" LE25-2 direct radiator - a cone type, not a dome - provides extended highs with a dispersion pattern of 90°, for wide but controlled coverage.

Rugged, no-nonsense cabinet and connectivity

The cabinet is wood, with either walnut veneer or gray finish, built to endure the knocks and bumps of studio life. Its bass reflex design enhances low-end extension without sacrificing cabinet rigidity. On the back, two 1/4" phone jack inputs provide reliable, professional-grade connectivity. The removable black fabric grille protects the drivers without muddying the sound.

Historical Context

The 4311B is the third generation of the 4311 series, which itself evolved from the compact professional monitor 4310. That model was developed in collaboration with studios to meet the demands of critical listening. The 4311 updated the 4310 with a smaller tweeter for improved high-frequency dispersion and adjusted crossover frequencies, aiming for a smoother, more balanced response. JBL marketed the 4311 as a compact, smooth, powerful, broadband monitor. Its widespread adoption in broadcast and recording facilities backed that claim.

The 4311B was part of JBL's 'Control Monitor' series, designed as an affordable professional monitor also embraced by home hi-fi enthusiasts. The 4300 Series launched in 1973, and the 4311B arrived in 1979 as a refined evolution of that lineage, balancing studio toughness with broader accessibility.

Collectibility & Value

Today, the JBL 4311B is described as highly sought-after, prized for its "West Coast" sound: forward, detailed, punchy, and engaging. Current market prices vary significantly based on condition, with working pairs typically selling between $750 and $1,200. Fully restored units, with refoamed surrounds, recapped crossovers, and verified drivers, command higher premiums.

Common problems include worn foam surrounds on the woofers, burnt voice coils from overdriving, and failing crossover capacitors due to age. Refoaming and crossover recapping are well-documented and widely supported by specialist shops. The 4311B has a reputation for rugged, durable construction, so with proper care it can perform as intended decades after leaving the factory.