Description
A single HALO-A exhibits a flat, free-field frequency response from 48Hz to 19kHz (±3dB) and a phase response which is ±20 degrees between 150Hz and 18kHz. Due to the unique loading technique applied to the low frequency drivers, combined with the high frequency waveguide, the dispersion pattern control is maintained down to 250Hz.
Similarly to HALO-C, the high frequency device is a major factor in setting the system apart from its competitors. Unlike HALO-C, which utilises an AMT plane-wave drive unit, HALO-A uses compression drivers due to the much higher SPL required for these applications. However, HALO-A uses a proprietary emulation manifold, which combines the energy of four 3.4” (86mm) diaphragm, 1.4” (36mm) exit compression drivers into a plane-wave array. This assembly gives not only a very significant moving area for the high frequency section, but provides twice the headroom of other comparable systems. Viewed from another perspective, if running at the same SPL as a competitor system, HALO-A would run with 3dB less distortion due to the increased overall HF headroom.
Working alongside these four high frequency drivers are a pair of high power 3.5” (88mm) voice coil 12” (305mm) low frequency transducers. These two powerful drive units, combined with optimally-tuned low turbulence porting and generous cabinet volume ensure HALO-A has a low frequency performance to match the stunning highs. Keeping HALO-A as a two-way system reduces the off-axis parallax issues to a single crossover point, and through tireless research and development this issue has been almost completely eradicated.
The HALO-A enclosure is constructed from premium 15mm and 30mm (⅝” and 1 3/16”) multi-laminate Birch plywood – rebated, screwed and glued together for maximum strength. Intelligent internal bracing, combined with the unique low-loss porting structure minimises panel flexure – thereby removing unwanted resonances but still keeping the overall enclosure weight low. The enclosure is finished in a polyurethane coating, which as well as being far tougher than the conventional water-based paints used on other products, offers HALO-A a significant level of weather resistance without any further treatment.
The flying hardware has also been built with touring flexibility and reliability in mind. HALO-A uses a 3-point system, utilising quick release pins as you would expect. Array angles can be pre-set on individual elements whilst stored on their transit carts. As the array is lifted the rear links move to their pre-set array angles, and a final pin fixes everything in position. Ultra-high tensile steel parts form the core of the 3-point system, which is coated with XylanTM – a fluoropolymer coating which contains PTFE for both lubrication and impact resistance. Arrays of up to 24 elements can be safely assembled with above-regulation safety factors.
HALO-A requires two amplifier channels and makes use of the latest in FIR DSP technology – as such it must be used with one of our Advanced System Amplifiers to function correctly. Using these amplifiers can be very efficient – up to eight HALO-A enclosures could be driven from a single DQ20, although four is recommended as a maximum for full output.
Video
Halo Arena Rigging Guide Final EN
How to rig the EM Acoustics HALO-A large format line array.