Ever since its initial prototype phase, Earthquake's PUMP-12 passive radiator module has left a lasting impression by increasing the subwoofer's SPL by up to +6dB. The PUMP-12 module features two 12-inch passive radiators that are combined and horn-loaded into a single unit. When integrated into a well-designed sealed subwoofer enclosure, the PUMP-12 can enhance bass output by up to +6dB without requiring additional amplifier power. Testing between a standard sealed enclosure and an Earthquake PUMPed enclosure revealed that the PUMPed enclosure's amplifier drew 30% less current than the former. With less current draw, the speaker's impedance increases, thus increasing SPL. The Earthquake PUMP-12 facilitates the transfer of high amplifier power into low-frequency output since the active driver doesn't have to battle against increasing pneumatic pressure in a closed cabinet or over-excursion near a port tuning frequency. Unlike in a standard sealed enclosure, where the pneumatic loading of the woofer rises as a function of its travel, causing compression, Earthquake's passive radiator technology faces no such limitations. The PUMP-12 works seamlessly with all good quality drivers and is ideal for high-output requirements where space is limited. It's essential to ensure that the combined piston area of the active driver(s) does not exceed that of the PUMP-12 (226 sq.in.) when selecting which active driver(s) to pair with the PUMP-12. Elevate your bass output with the Earthquake Sound PUMP-12.