JBL 4312C 3-Way Control Monitor Speaker Pair – Professionally Restored – 1-Year Warranty

$2,299

Classic JBL 4312C 3-Way Control Monitor speaker pair
12-inch low-frequency transducer with Aquaplas laminate cone
5-inch midrange transducer
1-inch pure-titanium high-frequency transducer
Factory-rated 45 Hz – 20 kHz ±3 dB frequency response
8-ohm nominal impedance and 100-watt factory power capacity
Front-panel Mid Frequency and High Frequency level controls
Tweeter protective mesh corrected during HQaudios service
Cleaned, reassembled, and completed a 2-hour post-service test
Backed by our 1-Year HQaudios Warranty

1 in stock

SKU: 1TOLC2836-LC Categories: SPEAKERS, JBL, Refurbished

Description
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JBL 4312C 3-Way Control Monitor Speaker Pair

Professionally Restored by HQaudios – Inspected & Tested – Backed by Our 1-Year Warranty

KEY HIGHLIGHTS

Classic JBL 4312C 3-Way Control Monitor speaker pair

12-inch low-frequency transducer with Aquaplas laminate cone

5-inch midrange transducer

1-inch pure-titanium high-frequency transducer

Factory-rated 45 Hz – 20 kHz ±3 dB frequency response

8-ohm nominal impedance and 100-watt factory power capacity

Front-panel Mid Frequency and High Frequency level controls

Tweeter protective mesh corrected during HQaudios service

Cleaned, reassembled, and completed a 2-hour post-service test

Backed by our 1-Year HQaudios Warranty

PRODUCT OVERVIEW

The JBL 4312C is a 3-way Control Monitor designed around the direct, dynamic presentation associated with JBL’s professional monitoring heritage. Its driver complement combines a 12-inch low-frequency transducer, dedicated 5-inch midrange, and 1-inch pure-titanium high-frequency transducer.

JBL designed the 4312C for demanding monitoring applications including recording, post-production, and broadcast environments. Front-mounted Mid Frequency and High Frequency level controls allow the tonal balance to be adjusted to suit placement and listening requirements.

This listing is for the actual pair shown in the photographs. HQaudios inspected all three driver sections, corrected a dented tweeter protective mesh, cleaned and reassembled the pair, and completed extended post-service functional testing before final release.

HQAUDIOS RESTORATION & TESTING

Before Restoration

When we received this JBL 4312C pair, we inspected the cabinets, grille assemblies, driver sections, front level controls, and overall speaker operation.

The cabinets showed scratches and age-related surface wear, while the black grille cloth showed visible age-related texture and wear.

Both low-frequency sections, both midrange sections, and both high-frequency sections were producing output during the functional inspection. One tweeter protective mesh was dented, although the tweeter itself remained operational.

All four Mid Frequency and High Frequency level controls were found operational.

During Restoration

Tweeter Protective Mesh: We carefully straightened the dented protective mesh on the affected tweeter.

Cleaning: We cleaned the speaker assemblies and exterior surfaces before final reassembly.

Reassembly: The complete pair was reassembled and prepared for post-service operational testing.

Functional Verification: We checked operation across the low-frequency, midrange, and high-frequency sections together with the front Mid Frequency and High Frequency level controls.

After Restoration / Final Testing

After cleaning and reassembly, we operated the complete pair through an approximately two-hour post-service test.

Low-Frequency Output: Both woofer sections produced output during system operation.

Midrange Output: Both midrange sections produced output during system operation.

High-Frequency Output: Both tweeter sections produced output during system operation, including the tweeter whose protective mesh had been straightened.

Level Controls: All four Mid Frequency and High Frequency level controls were operational during the functional evaluation.

Overall Operation: The complete pair successfully completed the post-service test with a final result of normal operation.

CONDITION

Technical Condition

Low-Frequency Drivers: Both 12-inch woofer sections are producing output and the complete pair passed post-service operational testing

Midrange Drivers: Both midrange sections are producing output and remained operational during system testing

High-Frequency Drivers: Both tweeter sections are producing output; the protective mesh on one tweeter was straightened during service

Mid / High Level Controls: All four front-panel level controls were found operational during functional inspection

Overall Operation: The cleaned and reassembled pair completed an approximately two-hour post-service functional test successfully

Cosmetic Condition

Cabinets / Wood Surfaces: Clean overall presentation with visible wood grain; light scratches, marks, and age-related surface wear remain

Front Baffles: Black baffle surfaces present cleanly overall with minor vintage marks visible on close inspection

Grilles: Black fabric grille assemblies are present and retain light age-related texture and wear

Low-Frequency Drivers: The light-colored woofer cones present cleanly overall with normal cosmetic variation visible in the actual photos

Midrange Drivers: Driver surfaces are intact with normal cosmetic variation consistent with vintage components

Tweeter Areas: One protective mesh was straightened during service; minor visual unevenness may remain under close inspection

Rear Panels / Terminals: Rear binding-post terminals and identification labels are present with light age-related wear

Overall Presentation: A clean vintage JBL pair that retains visible age-related cosmetic character

Bass / Midrange / High-Frequency Output Verified

Tweeter Protective Mesh Corrected

Level Controls Operational

Two-Hour Post-Service Test Completed

SPECIFICATIONS

Brand: JBL
Model: 4312C
Type: 3-Way Control Monitor Loudspeaker
Configuration: 3-Way, 3-Driver Bass-Reflex System
Factory Woofer: 12-inch (300 mm) JBL 2213H Aquaplas Cone
Factory Midrange: 5-inch (130 mm) JBL 104H-3 Felted Paper Cone
Factory Tweeter: 1-inch (25 mm) JBL 035TiA Pure Titanium Dome
Frequency Response: 45 Hz – 20 kHz (±3 dB)
Sensitivity: 91 dB SPL (1 W / 1 m)
Nominal Impedance: 8 Ohms
Power Capacity: 100 W
Crossover Frequencies: 1.5 kHz / 7 kHz
Factory Crossover Network: JBL 3112D
Factory Cabinet Material: Walnut Veneer Particle Board
Factory Grille: Black Fabric
Level Controls: Front-Panel Mid Frequency / High Frequency
Dimensions (Each): 14.25″ W × 23.5″ H × 11.75″ D
Net Weight (Each): 45 lbs (21 kg)

WHAT IS INCLUDED

1 Pair of JBL 4312C Control Monitor Speakers

Only the items specifically listed above are included.

Speaker stands shown in the photos are for display purposes only and are not included in the listed price. Please contact HQaudios if you would like to purchase the speakers with stands; discounted combo pricing may be available.

SHIPPING & PACKAGING

Your vintage audio equipment will be professionally packed by HQaudios using protective materials appropriate for its size, weight, and construction. Large or heavy items may be palletized and shipped by freight when required for safer transportation.

HQaudios Professional Shipping and Packaging

1-YEAR WARRANTY & CUSTOMER SUPPORT

Your purchase is backed by our 1-Year HQaudios Warranty. Our team provides support before and after your purchase. If you have questions about setup, operation, compatibility, or your order, please contact HQaudios for assistance.