JBL JRX 218 SUB 18" Compact Subwoofer

JBL Professional JRX218S – 18″ Compact Passive Subwoofer (4 Ω, 350 W Continuous)

The JBL JRX218S is an 18″ passive subwoofer designed to extend and reinforce low frequencies in live sound and music reproduction systems. It incorporates a robust 18″ JBL transducer with a 3″ voice coil and stamped steel frame, housed in a 19 mm MDF enclosure with a tuned port for deep, controlled bass. With a power handling of 350 W continuous (1400 W peak), a sensitivity of 98 dB (1 W/1 m), and a nominal impedance of 4 Ω, it delivers solid performance with a wide variety of power amplifiers. Its construction includes heavy-duty black carpeting, a powder-coated 18-gauge perforated steel grille, and non-resonant steel handles for secure transport. A 36 mm pole socket (cast aluminum) is integrated on top, allowing a mid/tweeter enclosure to be mounted above the sub (optional SS3-BK accessory).

Main features

• 18″ JBL transducer with 3″ voice coil and stamped steel frame.
• Power: 350W continuous / 1400W peak; recommended power level 350–700W at 4 Ω.
• Frequency response (±3 dB): 53–250 Hz; range (−10 dB): 34–250 Hz.
• Maximum calculated SPL: 133 dB peak at 1 m.
• 19mm MDF bass-reflex enclosure, finished in black carpet.
• 18 gauge perforated steel grating with powder coating.
• Two Neutrik Speakon NL4 connectors in parallel for simple daisy-chain wiring.
• Non-resonant steel handles for durability and safe transport.
• Base with 36mm top receptacle (cast aluminum) compatible with SS3-BK mast.
• Compact dimensions for its class: 605 × 508 × 551 mm; net weight 32.2 kg.

Product benefits

• Powerful bass with control: Direct-radiating design and tuned port provide punch and extension without sacrificing definition.
• Easy integration: 4 Ω impedance and high sensitivity to achieve high levels with reasonable power stages.
• Ready for live performance: 19mm MDF construction, steel grille, and sturdy handles withstand heavy use.
• Flexible configurations: dual Speakon connectors in parallel for linking enclosures and a 36mm top mast for mounting a satellite without truss.
• Compact footprint: Balanced dimensions and weight make it easy to transport and set up in tight spaces.

Use cases

• PA systems for bands, DJs, and rental companies requiring subwoofer reinforcement.
• Mobile or semi-fixed installations in bars, small rooms and school auditoriums.
• Configurations with 12″ or 15″ mast-mounted satellites for compact front-of-house rigs.

Frequently Asked Questions

• Is it active or passive? Passive. Requires an external power amplifier.
• What is the recommended amplification power? Between 350 and 700 W at 4 Ω per box for best performance without the risk of overload.
• What connectors does it use? Two Speakon NL4 connectors in parallel for input and connection to another unit.
• Can a satellite be mounted on top? Yes, it has a 36mm top mount compatible with the SS3-BK mast (not included).

Description for projects

Compact 18″ passive subwoofer, 4 Ω, 350 W continuous power (1400 W peak), 98 dB sensitivity (1 W/1 m), max. SPL 133 dB peak, 53–250 Hz (±3 dB) / 34–250 Hz (−10 dB) response, 19 mm MDF bass-reflex enclosure with black carpet, 18 gauge perforated steel grille, dual parallel NL4 Speakon connectors, 36 mm top receptacle, dimensions 605 × 508 × 551 mm, weight 32.2 kg, JBL M118-4 transducer.