Name: SXH218
Rating: 4.7 (23 reviews)

The SXH218 is an extremely powerful subwoofer capable of producing peak SPL of 148 dB at 1 m (154 dB peak with crest factor 4). It is the ideal partner for Wavefront Precision WPC and WPL arrays where maximum low frequency output is required as well as a standalone solution for premium permanent installations such as nightclubs.

Features

Ultra-high output ground-stacked subwoofer
Hybrid® horn/reflex loading for maximum acoustic efficiency and low frequency extension
Dual long-excursion 18” (460mm)/4.5” (115mm) voice coil neodymium drivers
Forward or rear-facing operation

Applications

Outdoor festivals
Stadiums, arenas and theatres
Concert halls
Nightclubs
Outdoor restaurant, bar and hotel entertainment areas
Concourses and Theme Parks

Its Hybrid® horn/reflex loading combines the acoustic efficiency and impact of bass horn technology with the low frequency extension of a reflex design, enabling it to produce significantly higher output levels than a traditional reflex-loaded subwoofer. With an operating range of 32-150Hz ± 3dB, it features dual long-excursion 18” (460mm)/4.5” (115mm) voice coil neodymium drivers, with water resistant cones and triple roll surrounds.

Also available is the SXHF218, a version of the SXH218 with flying hardware. It can be incorporated at the top of a WPL array, or more commonly flown as a separate array alongside. Like the ground-stack version, a combination of forward and rear-facing enclosures can be configured with specific directional properties.

Both the SXH218 and SXHF218 can be powered by either a single channel of a Martin Audio iK42 4-channel amplifier, or a bridged pair if maximum output is required. The connector sockets are wired so that one four-core cable from the amplifier will power two subwoofers. Subwoofer settings are determined by a pre-determined parameter set in Vu-Net when used in conjunction with iK42, or settings are available from the Martin Audio website when used with alternative amplifiers.

We provide this subwoofer with a set of four castors. A transit cover is available as optional accessory.

From Q2 2026, the SXH218 has front and rear LED indicators and adds a front‑mounted NL4 input connector, bringing the total to three NL4 connectors, including the two on the rear. A new grille and updated connectors allow this version to meet stringent environmental testing standards.

You can illuminate the LED indicators via Vu‑Net software to identify each enclosure on the circuit. The rear LED is intended for use in cardioid setups.

The third NL4 input connector on the front improves cabling for subwoofers used in cardioid configurations. For outdoor use, you no longer need a WRKIT, but you must seal all three NL4 sockets. Use the correct cable connectors (NLT4FX or NLT4FX‑BAG) for connected sockets and install Martin Audio weatherproof NL4 sealing plugs in unused sockets. This provides an IP rating of IP54 for the connections.

Links

User guide Brochure Datasheet Settings [v2.2]

Specification

TYPE	Hybrid® horn/reflex subwoofer
FREQUENCY RESPONSE (1)	32Hz – 150Hz ±3dB, -10dB @ 27Hz
DRIVERS	2 x 18” (460mm)/4.5” (115mm) voice coil, long excursion, neodymium magnet, waterproof cone
RATED POWER (2)	3000W AES, 12000W peak
Recommended Amplifier	iKON iK42 bridged for full output
SENSITIVITY (10)	107dB
MAXIMUM SPL (9)	142dB continuous, 148dB peak, 154dB peak with crest factor 4
NOMINAL IMPEDANCE	4 Ohms
DISPERSION (-6dB)	Omnidirectional/or Cardioid (paired)
ENCLOSURE	Multi-laminate birch/poplar ply
FINISH	Hard-wearing textured black paint (RAL 9005)
PROTECTIVE GRILLE	Black perforated steel
ENVIRONMENTAL TESTING (for details click here)	IP rating IP21 MIL-STD-810H ISO 4892-2 Solar Radiation ISO 12944-6 Category C3 Corrosion resistance
LED INDICATORS	Two LEDs: one front, one rear (rear LED for cardioid subs)
CONNECTORS	3 x NLT4MPXX-BAG (one front, two rear) IP54 weather-resistant seal with NLT4FX, NLT4FX-BAG or weatherproof NL4 sealing plug
PIN CONNECTIONS (INPUT ON FRONT)	1+/1-
PIN CONNECTIONS (INPUT ON REAR)	1+/1-
PIN CONNECTIONS (LINK ON REAR)	1+/1- linked to 2+/2- 2+/2- linked to 1+/1-
FITTINGS	Two skids on base, with mating channels on top Four rear-mounted 100mm (4in) castors supplied 6 x bar handles, 3 on each side 4 x fittings for optional transit cover
DIMENSIONS (INCL SKIDS)	(W) 1112mm x (H) 609mm x (D) 1023mm (1151mm incl. castors) (W) 43.8in x (H) 24in x (D) 40.3in (45.3in incl. castors)
WEIGHT	116kg (256lbs), with castors 120kg (265lbs)
ACCESSORIES	Transit cover SXH218TC Weatherproof NL4 sealing plug

Architectural Specs

Martin Audio SXH218

The loudspeaker shall be a hybrid® horn/reflex subwoofer consisting of two 18‑inch (460 mm) long‑excursion low‑frequency transducers with 4.5‑inch (115 mm) voice coils. The on‑axis frequency response shall be 32 Hz–150 Hz ±3 dB, with a –10 dB point at 27 Hz. The loudspeaker shall produce a maximum SPL of 148 dB peak or 154 dB peak with crest factor 4.

Power handling shall be 3000 W AES, 12 000 W peak, and the rated impedance shall be 4 ohms. The loudspeaker shall be fitted with three NL4 connectors (one on the front, two on the rear). The loudspeaker shall be operated in conjunction with a dedicated controller amplifier, with iKON iK42 in bridged mode recommended for full output.

The loudspeaker shall be capable of forward or rear‑facing operation to support the creation of ground‑stacked subwoofer arrays. The enclosure shall be constructed from multi‑laminate plywood, finished with a hard‑wearing textured black paint (RAL 9005). The drivers shall be protected by a black perforated steel grille.

The enclosure shall be fitted with two skids on the base with mating channels on top, four rear‑mounted 100 mm (4 in) castors, bar handles and four fittings for an optional transit cover. Two LED indicators, one on the front and one on the rear, shall allow enclosure identification via Vu‑Net, with the rear LED intended for cardioid configurations. Dimensions including skids, excluding castors (W × H × D) shall be 1112 mm × 609 mm × 1023 mm (43.8 in × 24 in × 40.3 in).

Dimensions including castors shall be 1112 mm × 609 mm × 1151 mm (43.8 in × 24 in × 45.3 in). Weight shall be 116 kg (256 lb) or 120 kg (265 lb) with castors.

The loudspeaker shall be the Martin Audio SXH218.

Technical Drawings & 3D Models