The S-215 is a compact high power subwoofer, and whilst derived from the flyable ST-215 it is a standalone product in its own right and can be used to support any EM Acoustics product in a ground stack configuration.

The compact enclosure houses a pair of 4” voice coil, 15” (381mm) neodymium drive units, in an optimally-tuned reflex design with a single low-velocity port to minimise distortion generated by turbulence. The drive units’ high motor strength gives the S-215 excellent transient response, and the moving area of the two high-excursion 15” drive units generate significant low frequency extension and overall subwoofer output. The enclosure is symmetrical, so in ground stacked configurations one enclosure in every three can be rotated to point physically backwards to create a cardioid array. Such arrays offer exceptional low frequency directivity control and significantly reduce the energy radiating to the rear of the subwoofers.

The robust enclosure is constructed from premium 18mm (¾”) multi-laminate Birch plywood – rebated, screwed and glued together for maximum strength. The enclosure is finished in our 3-step polyurethane coating, which as well as being far tougher than conventional water-based paints used on other products offers the S-215 a significant level of weather resistance without any further treatment.

The mechanical package is completed by a mesh-backed steel grille, eight recessed bar handles (four per side), protective stacking runners and mating recesses for use in both portrait and landscape orientations, and two M20 threaded pole adapters. The S-215 is supplied with castors for the rear as standard.  Three M8 threaded fittings are provided on the top of the enclosure for attachment of the GS-HALO-B ground stack frame, and assembly of HALO-B ground stack systems.  Inputs are provided on a pair of Neutrik speakON NL4 connectors for input and enclosure link.

The S-215 requires a single amplifier channel and an active crossover to function correctly – as such it is recommended to be used with the DQ10 or DQ20 advanced system amplifiers. Using these amplifiers a maximum of eight S-215 subwoofers could be driven from a single DQ20 amplifier. For cardioid arrays, separate amplifier channels are required for the rear-firing subwoofer(s) due to the different processing needed.