Description
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.
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.
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.
Product 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
Product Specification
Type: Hybrid® horn/reflex subwoofer
Frequency Response: 32Hz – 150Hz ±3dB, -10dB @ 27Hz
Driver: 2 x 18” (460mm)/4.5” (115mm) voice coil, long excursion, neodymium magnet, waterproof cone
Rated Power: 3400W AES, 13600W peak
Recommended Amplifier: iKON iK42 bridged for full output
Sensitivity: 107dB
Maximum SPL: 142dB continuous, 148dB peak, 154dB peak with crest factor 4
Nominal Impedance: 4Ω
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:
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): Input +1/-1
Pin Connections (Input on Rear): Input +1/-1
Pin Connections (Linkon 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: 124kg (273lbs), with castors 127.5kg (281lbs)
What's in the Box?
SXH218 Subwoofer
4 x Castor Wheels
