Powersoft D-Cell504 IS high-power amplifier modules have been designed to drive a unique “Wall of Bass” (as low as 7 Hz) in an Austrian nightclub.
The newly-reconstructed Club SUB, in the city of Wiener Neustadt, set out to integrate a perfect low-frequency solution, capable of reproducing a wide range of live and DJ-derived music (e.g., Drum ‘n’ Bass, Dubstep, and Techno) and arts presentations, as well as workshops and theatrical performance in a completely revolutionary way.
And since the 300-capacity club is located in a heavily populated residential area emphasis needed to be placed on acoustic isolation.
Project managers, Wolfgang Sauter (from Pro Performance) and Reinhard Nell (from Lambda Labs), were equal to the challenge.
Lambda Labs German-based director, Steffen Kroschel, said, “The owners’ goal was to achieve a similar sound performance as it had in the Grelle Forelle Club in Vienna. Given the concerns of local residents, when Mr. Sauter surveyed the building, with its tube like architecture, the abstract idea of a ‘vibrating wall’ became more logical.”
He contacted Lambda Labs where Richard Nell supported the concept with simulation data, parameters, and measurements— applying his knowledge of high-performance concrete “closed box” enclosures and amping. The drivers were developed especially for this application, going through 10 prototype stages, while the club owners helped with casting the concrete loudspeaker enclosures.
For the rear wall, behind the 6 m × 5 m stage, 400-kg special concrete blocks were cast and set into a 6 m × 3 m wall, using 13 tons of heavy concrete and a further 35 tons for the foundation—requiring a monumental effort. “It was extremely difficult to handle these enclosures with small forklift trucks and build the 50 cm deep low-frequency absorber,” said Kroschel. “Behind the wall is sand, and under the wall, Mr. Sauter chose material that is used for highway construction.”
Each concrete block serves as a loudspeaker enclosure with a pressure-resistant rear chamber that implements the perfect impulse response of a “closed-box” design and maximizes the radiation resistance of the woofers through the acoustically hard surface. A self-enveloped 15” speaker was produced and adapted to the unusual demands of this project. The single chassis are designed to act together like one single swinging wall—in a similar principle to a piston in a cylinder.
Kroschel explained, “A perfect plane wave is created in the interior of the club, which naturally moves along the side walls and doesn’t induce any room modes. The rear of the main floor was converted into a single bass trap to absorb the incoming wave. The SUB thereby achieves an acoustical result that could never be reached even outdoors.”
Outside, virtually no noise escapes. And Nell and Sauter, agree that “such an operating range and evenness of the low frequencies is overwhelming.”
But to achieve this optimum performance, every driver needed be powered by its own dedicated amplifier module to take advantage of the shortest cable runs, matching power supplies, and impedance data. Nell chose Powersoft, a longtime partner of Lambda Labs, to provide amping for the “Wall of Bass.” Lambda Labs supported the installation with items like amplifier mounting frames.
The 32 Lambda Labs OEM CX 15” ultra-long excursion drivers, with ± 25-mm linear excursion capability, are set in housings made from special concrete. Each is driven by 800-W amplifying modules, with the maximum desired sound pressure level (SPL) reached at an excursion of only ±3 mm. Therefore, the “Wall of Bass” only uses 500-W peak music power during operation, which sets new standards of energy efficiency.
Via their two-channel 32 D-Cell504 IS amp modules, Powersoft delivered 25,600-W amping power, including four-in voice coil with a custom-made venting system that has a hardened membrane.
Integrated within an aluminum heatsink panel, the D-Cell504 IS provides an interface panel with input volume potentiometer, double XLR for mono input and link out or stereo input operation, four LEDs for limit, clip, signal, and ready, with a four-LED preset selection button to show the preset in use. Easy access to the DSP mounted on board, is further facilitated via remote control capabilities provided by Powersoft’s proprietary Armonía Pro Audio Suite.
For more information, visit www.powersoft-audio.com