Three-way, Bi-amp Array Element

The scalable resolution of WPL [Wavefront Precision Longbow] offers greatly improved coverage consistency and control compared to a standard line array and provides a flexible pathway to advanced array control.


  • High-performance large format line array
  • All-horn, maximum-efficiency design
  • Exceptional signature sonic performance
  • Exemplary 90° horizontal constant directivity pattern control
  • External, dedicated, multi-channel Class D amplification
  • Scalable resolution for flexible optimisation of coverage, consistency and control
  • Industry-leading DISPLAY software interacts with DSP for highly-accurate array optimisation
  • Fast, integral 3-point rigging for up to 24 enclosures
  • Compact and light weight design with discreet side handles for ease of handling


  • Consistent coverage achieved ‘straight-out-of-the-box’
  • DISPLAY intelligent software reduces set-up time and eliminates trial-and-error
  • Improved audience coverage with reduced sound-spill


  • Touring sound reinforcement for festivals, stadiums and arenas
  • Sports stadium and arena installations
  • Concert hall and HoW installations

With the launch of the Wavefront Precision™ Series (WPM and WPC) the concept of scalable resolution was born — harnessing the research and technology behind Martin Audio’s self-powered MLA® Series systems in a new line array format with external amplification.

Delivering unmatched sound quality, coverage consistency and control in an affordable package, this uniquely flexible and upgradeable approach has been rapidly adopted by sound rental and installation companies worldwide to become the company’s fastest ever selling line array series.

Wavefront Precision Longbow (WPL) now brings this high performance, control and flexibility to large-scale touring and install applications. Designed as a complete system with external iKON® multi-channel amplifiers, automated DISPLAY™ optimisation software and VU-NET™ control platform, WPL provides financial accessibility to the top echelons of touring and install sound — from prestigious stadium concert and outdoor festivals, to high-specification arena and House of Worship installations.

The complete system philosophy guarantees that WPL arrays perform predictably and effortlessly to their design maximum, as well as ensuring that they are compatible with other WPL systems throughout the world.

WPL is a full-scale line array which is capable of exceptionally high output for its modest size and weight.

A three-way, bi-amped system, its very high output is achieved by utilising Martin Audio’s trademark horn-loading technology across all frequency bands — increasing the acoustic output of the low frequency section, as well as the midrange and HF.

It incorporates 2 x 12” (300mm) drivers with Hybrid® horn/reflex loading, 2 x 6.5” (165mm) cone drivers on a midrange horn which covers the vocal frequency range from 300Hz to 4kHz, and 3 x 1” (25mm) exit HF drivers operating from 4kHz upwards. Each section features innovative horn-loading techniques and refinements which raise the acoustic performance of WPL to a superior level — both in terms of output and smooth 90° horizontal coverage patterns of the mid and HF horns. Sonically, WPL’s exemplary horizontal dispersion pattern translates to an incredibly consistent frequency response off-axis, with minimal variation from the on-axis response.

The maximum peak outputs of the LF, Mid and HF sections are 139dB, 140dB and 145dB per enclosure @ 1m and 6dB crest factor, respectively — ensuring that a WPL array will meet the most demanding requirements for throw and clarity in the largest venues and outdoor events.

As well as delivering exceptional sonic performance, WPL is designed to meet the everyday practical challenges encountered by tour sound crews and installers. Its modest size and light weight – just 64kg (141lbs) – are born from detailed attention to all aspects of its physical design, and a range of accessories ensure that it is easy to transport and fast to deploy.

The WPL enclosure is constructed from plywood and finished as standard in a tour-ready, heavy-duty Warnex finish (PU coated available as an option). Two side pocket handles on each side assist handling, while their discreet design is perfectly suited to installation. An integrated three-point rigging system assures efficient and safe construction of arrays of up to 24 enclosures. A rigid perforated steel grille protects the front of the enclosure.

With unmatched line array performance inherent in the acoustic design of WPL, scalable resolution offers versatility in the way a WPL array is powered and optimised. The greater the number of individually driven enclosures, the more precisely DISPLAY can fine-tune the array’s coverage, consistency and control within the venue. The advantages of higher resolution over a uniformly-driven line array are very significant — with front-to-rear frequency responses kept closely aligned and with greatly reduced output behind the array.

Bi-amped, with a passive mid/high crossover, a 12-enclosure array can be driven by either 3 x iK42 amplifers (2-box resolution) or 6 x iK42 amplifiers (1-box resolution). With the number of amplifiers determined to suit the venue, the application and the budget, the commercial advantages of scalable resolution are clear:

  • Design systems to suit budget targets
  • Dynamic deployment within a venue or site where the main PA is driven with more amplifier channels than may be necessary for delays
  • Adaptable rental pricing based on event dynamics and clients’ resources

For special case installations that require the ultimate resolution, it is possible to by-pass the internal passive crossover and control individual transducers independently. This maximum resolution case offers full MLA-type control, but with the external, ground-based amplification some installers prefer for large-scale fixed installations and stadiums.

DISPLAY is an extremely powerful prediction and array configuration tool. Instead of using a standard geometric model, DISPLAY is based on an industry-leading acoustic model accurate to within ±1dB of measured data, and delivers unrivalled coverage consistency over the audience — right from switch-on.

DISPLAY takes trial-and-error out of array deployment — generating highly-accurate SPL and frequency response predictions throughout the venue, as well as providing comprehensive rigging information, including mechanical safety analysis. DSP parameters calculated by DISPLAY are easily uploaded to the iKON amplifiers via Ethernet, using Martin Audio’s VU-NET real-time control and monitoring software.

By reducing sound impacting non-audience areas, rear walls and ceilings, DISPLAY mitigates the detrimental influence of the venue acoustics — increasing clarity and intelligibility. DISPLAY’s Hard Avoid® function can also be used to reduce sound-spill onto stages and rapidly reduce throw beyond a festival perimeter. Significantly, DISPLAY’s ability to keep off-site sound within strict limits while maximising audience levels out-front can bring new life to previously unworkable outdoor events.

WPL is designed as a complete system with dedicated, high-performance iKON multi-channel Class D amplifiers. For 1-box and 2-box resolution, the iK42 4-channel amplifier delivers very high power outputs and features high-speed Ethernet communication for system control and monitoring via Martin Audio’s VU-NET software, plus Dante™ digital audio networking. With the option to transmit digital audio over a single CAT5 cable, quality is maintained over long cable runs and integration with other devices in the sound system is straightforward.

For the ultimate resolution install case, where each mid and HF transducer is driven independently, a complement of iK42 4-channel and iK81 8-channel amplifiers power the bass section, each mid and HF driver individually.

Because the amplifiers are external to the loudspeaker enclosures, the resolution of the array can be increased as required by simply adding more amplifier channels to drive more array enclosures independently — increasing the level of control available to DISPLAY to fine-tune coverage and reduce room influence. External amplifiers also facilitate ease-of-servicing in fixed installations.

Hybrid technology combines the efficiency and impact of a bass horn with the low frequency extension of a bass-reflex enclosure. With a typical efficiency improvement of 4dB compared to direct radiator low-end designs of competitors, a WPL array has a noticeable advantage over direct radiator arrays when projecting maximum LF output over distance.

The LF section utilises 2 x 12” (305mm) drivers front-loaded by separate hyperbolic horns for maximum efficiency and rear-loaded by a reflex ported chamber. A differentially flared port reduces turbulence and air noise. Spacing the mouths of the twin horns as far apart as possible within the enclosure assists directivity control down to 150Hz — reducing bass mid-bass output at the sides and rear of the array. The drivers themselves are designed for very high excursion and feature 3” (75mm) voice coils, neodymium magnet structures and forced air cooling to reduce power compression.

The patented mid-range section is central to the signature sound and superb horizontal pattern control of WPL. Compared to direct radiator midrange designs of competitors, the horn design of WPL mid has the advantages of both greater output and superior horizontal pattern control which does not vary significantly with frequency.

Featuring 2 x 6.5” (165mm) cone drivers with toroidal phase-bungs and mounted on a 90° horizontal constant-directivity horn, the midrange section covers the range from 300Hz-4kHZ. Crucially, operating over an entire decade means that the fundamental frequencies of the vocal range are reproduced by a single device and a single diaphragm material, thereby offering superior consistency and clarity against competitor designs that combine different device and diaphragm material.

Additionally, the low-compression ratio in the horn throat afforded by the patented toroidal phase bungs reduces distortion compared to high-compression horn designs and the HiBlade™ waveguide smooths and improves the horizontal directivity of the horn throughout its range. The technical refinements of the midrange horn contribute to the exceptionally powerful and smooth vocal performance of WPL.

Operating from 4kHz upwards, the HF section of the WPL utilises 3 x 1” (25mm) exit neodymium compression drivers mounted on individual horns with true 90° horizontal constant directivity characteristics.

Competitors traditionally use large format compression drivers in line arrays which typically cross-over an octave lower, resulting in increased distortion and harsh sound just where the ear is at its most sensitive.

In contrast, the high 4kHz crossover point enabled by the midrange horn design, together with the use of smaller HF diaphragm drivers means that WPL delivers pristine high frequency sound with much lower distortion than traditional designs — with the added benefit of a more extended extreme top-end not achievable from large-format devices operating in the break-up region at the upper end of their range.

Patented kite-shaped ‘wedges’ in the throat of each horn flatten the curvature of the wavefront so that the HF section operates as a true line array.


Safety, simplicity and speed are essential aspects of a rigging system which the WPL three-point rigging system fully addresses. The rigging design allows for suspension of up to 24 enclosures, with DISPLAY software calculating the splay angles from 0°-7.5° needed to produce the desired vertical coverage. DISPLAY also determines the safe limits and tilt angle of an array and confirms compliance with specific safety standards, including BGV-C1, prior to deployment.


The front hinge points at the top of each WPL enclosure over-extend to ensure that there is plenty of ‘finger-room’ for riggers to pin enclosures together. As well safeguarding hands, this over-extension also gives useful latitude when connecting the lowermost box in an array to the uppermost box on a dolly which may not be on level ground, such as a festival site. As the hang is lowered, a second pin locks the hinge in place in its unextended position to minimise the gap between enclosures at the hinge point to just a few millimetres, ensuring vertical coverage consistency.


The rear rigging point sets the inter-cabinet splay angles determined by DISPLAY, and the design allows the angles to be easily set by a quick-release pin while enclosures are in their closed-up transport positions on the dolly. Once the uppermost enclosure on the dolly is attached to the array and the array is lifted, the dolly enclosures open up to the correct splay angles. A second pin locks each in place.


The SXH218 is a highly-powerful ground-stack subwoofer capable of producing 148dB peak output at 1m. 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. In most applications this means fewer subwoofers are required to achieve better results than standard reflex-loaded subwoofers. 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.

The enclosure is constructed from multi-laminate plywood and finished with a rugged polyurea coating. A rigid perforated steel grille protects the front of the enclosure, while interlocking skids protect the top and bottom surfaces and prevent movement when stacked.

The SXH218 can be powered by either a single channel of an iK42 4-channel amplifier, or a bridged pair if maximum output is required. DSP settings for each SXH218 are determined by DISPLAY™ and uploaded to the iK42 over Ethernet via the VU-NET™ real-time control and monitoring interface. A combination of forward and rear-facing enclosures can be configured by DISPLAY as a directional subwoofer array with specific directional properties, including cardioid.


The SXHF218 is 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.

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Distro for iK42
ROW version


Distro for iK81
ROW version


Distro for iK42
US version


Distro for iK81
US version


Ground stack kit
for WPL


Transport cart
for WPL


Amplifier rack
for iK42


Amplifier rack
for iK42


9U amplifier rack
for iK42 and iK81


Touring flying frame for WPL and SXHF218, available in black or white


for WPL


Distro panel for
iKON amplifier racks


Install flying frame for WPL
Available in black or white

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18″ Subwoofer

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20,000 Watts RMS


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