The PXL118 makes use of a hybrid design to achieve high peak sound pressure while producing deep bass well below 50 Hz. Even under maximum load, the impulse response accuracy is astonishing. The PXL118 is a punchy, rich-sounding subwoofer specifically designed to match the PXH64 mid/tweeter that extends its frequency response down to 50 Hz. Its cabinet shape, size, and fly arrangements are fully compatible with the PXH64. The PXL118 makes use of a hybrid design to achieve maximum high sound pressure while producing deep bass well below 50 Hz. Even under maximum load, the precision of the impulse response is amazing. The PXL118 is a punchy, rich-sounding subwoofer specifically designed to match the PXH64 mid/tweeter that extends its frequency response down to 50 Hz. Its cabinet shape, size, and flight arrangements are fully compatible with the PXH64 ..PZA MORE SPECS