Martin Audio SX218 – 2x18" Passive Direct-Radiating Subwoofer (Black)

Product Overview

The Martin Audio SX218 is a dual-driver, direct-radiating passive subwoofer engineered for applications demanding very high LF output levels with superb transient performance and minimal distortion. Featuring two 18" (460mm) long-excursion drivers with 4" (100mm) voice coils, waterproof cones, and ferrite magnets, the SX218 is suited to touring sound reinforcement, large permanent installations, sports stadium AV, and corporate events where a single 18" driver is acoustically insufficient. Tour-grade plywood construction with integrated flying inserts supports both ground-stack and rigged deployment.

Product Description

The SX218 builds on the SX118 single-driver architecture by adding a second 18" (460mm) long-excursion driver, providing materially higher LF output capability and headroom for demanding reinforcement applications. Both drivers feature 4" (100mm) voice coils, waterproof cones, and ferrite magnet structures — the same high-quality driver specification as the SX118 — within a shared tour-grade plywood enclosure with integrated flying inserts. The waterproof driver cones extend deployment flexibility to outdoor and semi-exposed environments. Updated driver specifications from January 2019 improve on the earlier SX218 iteration. The SX218 is the appropriate choice for concert halls, theatres, ballrooms, stadiums, and large houses of worship where the LF output demands exceed what a single 18" can deliver, or where dual-driver stiffness provides additional system reserve at the same listening levels. It pairs with Martin Audio WPS, WPC, and WPL line array systems for large-venue touring and permanent installation LF reinforcement.

Key Features

• Dual 18" Long-Excursion Drivers — Two 460mm drivers with 4" voice coils deliver very high LF output levels with low distortion.
• Waterproof Cones — Enables deployment in outdoor and semi-exposed environments.
• Ferrite Magnet Structure — High-efficiency magnetic assembly supports sustained high-power LF operation.
• Very High Output Capability — Superb transient performance with minimal distortion at demanding SPL levels.
• Tour-Grade Plywood Enclosure — High-durability construction meets touring and permanent installation demands.
• Integrated Flying Inserts — Supports both ground-stack and rigged overhead deployment configurations.

Typical Applications

• Touring sound reinforcement for medium and large venues
• Concert halls and theatres requiring high LF headroom
• House of worship main LF reinforcement systems
• Sports stadiums and arenas with high-output LF requirements
• Hotel ballrooms and large multi-purpose performance rooms
• Corporate AV events requiring high LF output

Technical Specifications

Frequently Asked Questions

Is the SX218 a passive or powered subwoofer?

The SX218 is a passive subwoofer requiring an external power amplifier and DSP processor for crossover management and system alignment.

How does the SX218 differ from the SX118?

The SX218 adds a second 18" driver for significantly higher LF output capability compared to the single-driver SX118, at the cost of a larger and heavier enclosure.

Can the SX218 be flown?

Yes. Integrated flying inserts support rigged overhead deployment in addition to ground-stacking.

Is the SX218 suitable for outdoor use?

Waterproof driver cones extend deployment to outdoor and semi-exposed environments.

Has the SX218 been updated?

Yes. The SX218 driver specification was updated in January 2019, improving on the earlier iteration.

Is a white version available?

Yes. The SX218-W is the white finish variant for permanent installations.

Where can I view the full Martin Audio SX range?

Visit creationnetworks.net/collections/martin-audio for the complete SX Series lineup.