Architect and Engineer’s Specifications: 
AD-S.SUB Small Format Surface Subwoofer

The subwoofer enclosure shall contain a low-saturation, low-loss transformer so it can operate on 70- or 100-volt distributed lines, or as a direct low-impedance system when the transformer is bypassed. The transformer shall have multiple taps to allow selection of the desired power level on 70- or 100-volt lines. The subwoofer shall feature a 6.5-inch dynamic woofer driver with a weather-treated paper cone and a rubber surround. 
The driver shall have dual 8-ohm voice coils. A MONO/STEREO selector rotary switch shall, when set to MONO, connect the coils in parallel for monaural operation on a 70- or 100-volt distributed line or as a 4-ohm load when the transformer is bypassed; when set to STEREO, the switch shall keep the coils separate as two 8-ohm loads and shall also separate the satellite loudspeakers into left and right. The MONO/STEREO switch shall be located on the rear panel of the subwoofer enclosure. A second rotary switch on the rear panel of the enclosure shall offer this selection of power levels, as well as a transformer bypass: 100, 50, 25, and 12.5 watts (70 volts); 100, 50, and 25 watts (100 volts). Both switches shall be accessible under a removable, reversible snap-fit ABS plastic cover.
The subwoofer enclosure shall contain a passive crossover filter system, with the 150 Hz low-pass filter delivering content into the subwoofer driver and the 200 Hz high-pass filter delivering content for the satellite loudspeakers to output connectors on the enclosure.
The subwoofer shall have an effective frequency range of 45 Hz to 150 Hz and an on-axis free-air sensitivity of 86 dB SPL, measured at 1 m with an input signal of 2 V rms. It shall be capable of producing a peak maximum output of 106 dB SPL, measured at 1 m. The subwoofer’s continuous power rating, measured with an IEC60268-1 noise signal for two hours, shall be 100 watts (20 volts rms with transformer bypassed).
The subwoofer enclosure shall be constructed of vinyl-wrapped medium-density fibreboard with a front baffle made of ABS plastic. It shall have a reversible rear cover over its connectors and switch knobs. The subwoofer shall be available in either RAL 9010 white or RAL 9011 black.
The connectors on the subwoofer enclosure shall be four locking four-pole “Eurostyle” pluggable terminal blocks located on the rear panel of the enclosure. One input terminal block shall offer two connection points, + and -, for the loudspeaker cabling and two more parallel loop-through connection points for connecting forward to another subwoofer unit, if necessary; the second input terminal block shall offer stereo (left and right) connection points, + and -. A third four-pole terminal block shall provide high-pass + and - outputs for two satellite loudspeakers (SAT 1 and SAT 2), and a fourth shall provide high-pass + and - outputs for satellites SAT 3 and SAT 4, if necessary.
Included with the subwoofer enclosure shall be a kit of four adhesive rubber feet for placement on a horizontal surface. Also included shall be a two-part steel V-mount bracket for optionally attaching the subwoofer to a wall or vertical surface; the bracket shall include a locking screw to secure the two parts together. The enclosure shall be rectangular with dimensions of 432 mm (17 inches) long, 350 mm (13.8 inches) high, and 209 mm (8.23 inches) deep; when wall-mounted, the bracket shall add 22.5 mm to the depth. The subwoofer system shall weigh 10.7 kg (23.5 lb) net.
The subwoofer shall be the QSC AD-S.SUB.