K Series KSub Dual 12" Active Subwoofer Summary description: A lightweight portable powered subwoofer system with dual 12-inch drivers in a 4th order bandpass configuration. Drivers: The subwoofer system shall incorporate two 12-inch (300 mm) low frequency transducers. Enclosure: The subwoofer system shall be housed in a bandpass enclosure constructed of birch plywood. The enclosure shall be finished with textured black paint. The back of the enclosure shall have a panel for the connectors, switches, and controls of the amplifier module. The back of the enclosure shall have four 3-inch low-noise heavy-duty casters. The top and bottom of the enclosure shall each have cast aluminum handles. The top of the enclosure shall have a threaded M20 pole receptacle for an included threaded speaker pole. The bottom of the enclosure shall have slip-resistant feet. Electronics: The subwoofer system shall incorporate a Class D amplifier. The amplifier shall have an output power of 1000 watts continuous (2 x 500 W) and 2000 watts peak. The subwoofer system shall incorporate circuitry enabling the following digital signal processing (DSP) functions: - Digital Extension and Excursion Processing (DEEP), a non-distorting low-frequency EQ circuit that provides increased low-frequency extension without distortion or over-excursion; - Intrinsic Correction, which evens the dispersion of energy throughout the physical listening area of the loudspeaker. I/O and connectors: The subwoofer system shall have the following input and output connections: - LINE INPUT connections A and B shall each be via a female hybrid 3-pin XLR/quarter-inch phone (TS or TRS) jack. When used with XLR connectors the inputs shall be balanced and have an impedance of 40 kilohms. When used with quarter-inch phone connectors the inputs shall be unbalanced and have an impedance of 20 kilohms. - Direct outputs A and B shall each be discrete balanced full-range line-level outputs accessed via a male 3-pin XLR jack; - REMOTE GAIN connection shall be via a 3-pin "Euro" jack; - AC INLET connection shall be a latching IEC connector that takes a V-Lock power cable (included) or a standard replacement 18 gauge IEC power cord. Controls and indicators: The subwoofer system amplifier module shall include the following controls: - Power ON/OFF switch; - Gain knob, which shall set the amount of input signal that is sent to the amplifier; - LF Mode switch, which shall select an operation mode of either DEEP or Normal (DEEP processing not applied); - Polarity switch, which shall select either Normal or Reverse polarity; - Front LED switch, which shall select whether the front LED tracks the rear-panel Power LED or the rear-panel Limit LED, or is off. The subwoofer system amplifier module shall include the following indicator LEDs: - POWER shall indicate that the power switch is in the ON position and the unit is not in Standby; - STBY (Standby) shall indicate that the loudspeaker system is in standby mode, which conserves energy when the unit is not in active use; - LIMIT shall indicate that limiting has taken place to avoid damage to the amplifier or loudspeaker; - SIGNAL shall indicate the presence of signal at the input connectors; - Front LED shall track the rear-panel Power LED, the rear-panel Limit LED, or be off, depending on the position of the Front LED switch. AC power requirements: The loudspeaker system shall have a universal power supply capable of operating with input AC power voltages ranging from 100 VAC to 240 VAC at 50 – 60 Hz. Power consumption at one-eighth power shall be 2.3 A at 100 VAC, 2.01 A at 120 VAC, and 1.13 A at 230 VAC. Cooling and protection: The loudspeaker system shall incorporate a 50 mm variable speed fan for on-demand cooling. The loudspeaker system shall incorporate amplifier protection circuitry including thermal limiting, output overcurrent protection, overtemperature muting protection, and GuardRail. The loudspeaker system shall incorporate transducer protection circuitry including thermal limiting and excursion limiting, which prevents woofer over-excursion. Performance criteria: The subwoofer system shall meet the following performance criteria: - Frequency response shall be within -6 dB at 48 Hz to 134 Hz; - Useable frequency range shall be within -10 dB at 44 Hz to 148 Hz; - Maximum SPL at one meter shall be 130 dB (based upon transducer sensitivity and peak available amplifier power). Dimensions and weight: The subwoofer system shall have the following physical characteristics (dimensions include casters): - Height shall be 26 inches (665 mm); - Width shall be 14 inches (356 mm); - Depth shall be 28.1 inches (714 mm); - Net weight shall be no more than 74 lb (33.6 kg). Model: The subwoofer system shall be the QSC Audio Products KSub.