Hertz CBA 250 active subwoofer box, with the 10-inch driver, features a dedicated high-performance amplification module that enhances all the passive box technologies, such as the 2S2 (2 Sides, 2 Sounds) design, the plug-and-play terminal block and ultra-compact size. The SSP (Sub Smart Plug) terminal block is provided with a single plug-and-play connector to be able to disconnect the box easily and safely. The amplification module, with power outputs of 250W RMS, is developed with he-li technology (high efficiency, low impedance), which thanks to the absence of the DC-DC voltage booster reach the impressive 90 percent efficiency level, very close to the theoretical limit of the D-Class. The Butterworth low pass filter at 12dB Oct. with variable cut-off frequency (50-200 Hz) can be bypassed, when used with an external processor with pre-out output dedicated to the sub. The adjustable bass-boost control (0 - 6 dB) at 45 Hz allows the user to emphasize the response on the lower side of the spectrum and the Phase control (0-180 degree) completes the equipment. The high-level speaker-in input on the multi-pole connector eases the integration with OEM audio systems while the low-level input on RCA is dedicated to the connection with after-market sources.