ARCS II - constant curvature WST® enclosure

The ARCS II features one 15’’ neodymium LF driver in a bass-reflex tuned enclosure and one 3’’ neodymium diaphragm compression driver coupled to a DOSC® waveguide. The ARCS II is based on an active 2-way design with a nominal impedance of 8 ohms for both the HF and the LF section. The ARCS II cabinet is made of first grade Baltic birch plywood to ensure maximum acoustical and mechanical integrity.

The ARCS II enclosure operates over the 50 Hz to 20 kHz nominal frequency bandwidth. This response can be lowered down to 25 Hz with the addition of the SB28 subwoofer.

The DOSC® HF waveguide generates a 22.5° symmetric x 60° asymmetric (-20°/+40°) directivity pattern. These values correspond either to the horizontal x vertical coverage angles, for an ARCS II enclosure standing vertically, or to the vertical x horizontal coverage angles, for an ARCS II enclosure in the radial orientation.

The ARCS II rigging system allows assembling a horizontal or vertical array with a constant curvature. The DOSC® waveguide in the HF region allows the system to be arrayed without breaking the inter-element acoustic coupling. The WST® (Wavefront Sculpture Technology) criteria are then fulfilled, so that such an array can be qualified as a true line source. An ARCS II line source provides a smooth tonal response and a coverage that is free of secondary lobes over the entire frequency range.

The ARCS II enclosure is exclusively driven and bi-amplified by the LA8 amplified controller. This one ensures active system linearization, intelligent transducer protection, and optimization for the loudspeaker system. With a single factory preset designed to be used in the different operation modes of the ARCS II, the performance of the system will depend upon the choice of the physical system configuration.

L-ACOUSTICS^® pioneered the field of modern line source array as early as 1993 with the introduction of Wavefront Sculpture Technology on the legendary V-DOSC^® system.

Based on physical rules developed by Heil and Urban (AES 1992) the WST^® theory defines five criteria for design and use of true line source arrays. At the heart of Wavefront Sculpture Technology is the internationally-patented DOSC^® waveguide, which morphs the spherical wavefront of the HF driver into a cylindrical, isophasic wave

In combination with WST^®, coplanar symmetry - the equivalent of coaxial assembly for HF, MF and LF drivers in vertical arrays - provides a coherent wavefront over the entire horizontal coverage at all frequencies. This behaves as if the sound was radiated by a single, continuous and articulated ribbon.

L-ACOUSTICS^® has been designing reference line array systems for more than 15 years.

The ARCS II benefits from a design exploiting L-ACOUSTICS’ Wavefront  Sculpture Technology® in a constant curvature line source solution.  Intended for medium to large rental productions, it delivers remarkable power, bandwidth and coherence, along with flexible and predictable coverage. It also offers the audience an incomparable listening experience featuring clarity, precision and impact.

• 50 Hz - 20 kHz ([ARCS II] preset)

• Horizontal: 22.5° symmetrical x N elements
• Vertical: 60° asymmetric (-20°/+40°)

• 140 dB ([ARCS II] preset)

* Peak level measured at 1m under free field conditions using 10 dB crest factor pink noise with specified preset and corresponding EQ settings.

• LF: 600 W
• HF: 100 W

• LF: 1 x 15" neodymium weather-resistant with 4’’ coil
• HF: 1 x 3"  neodymium diaphragm compression driver
• Nominal impedance: LF = 8 ohms, HF = 8 ohms

• LIFTBAR certified for 6 ARCS II in a horizontal array
• ARCBUMP certified for 4 ARCS II in a vertical array

*Mechanical data and limits for installation are specified in SOUNDVISION software which is designed to help with L-ACOUSTICS® product implementation.

• W/w x H x D: 439/190 x 820 x 652 mm
•                   17.3/7.5 x 32.3 x 25.7 in
• Weight (net): 50 kg / 110 lbs
• Connectors: 2 x 4-pin SpeakON®
• Cabinet: Baltic birch plywood
• Finish: Grey brown, RAL 8019®
• Front: polyester powder-coated steel grill Airnet® acoustically neutral fabric
• Rigging elements: steel with dual coating (zinc and polyester powder)

• Full range active 2-way WST® enclosure (provided with 2 coupling bars)
• Bandwidth = 50 Hz - 20 kHz

• Reference subwoofer enclosure
• LF limit = 25 Hz

• Amplified controller with DSP library and networking capabilities
• Touring rack
• Remote control software

• Removable front dolly board
• Protective cover

• Rigging structure for flying a horizontal array

• Rigging bar to use with 2 BUMP3 for flying a horizontal array

• Rigging structure for flying a vertical array (provided with 2 coupling bars)

• 3D electro-acoustic and mechanical simulation software dedicated to L-ACOUSTICS® products

“We purchased our ARCS II systems without even hearing them based on the description of the product and our experience with the original ARCS. It has been such a fantastic speaker for us to begin with, we knew that ARCS II just had to be more than fantastic, and it really is. We’ve been very happy with the new ones so far and look forward to increasing our inventory of them and other L-ACOUSTICS products in the new year.”