APS 10 S4S - SUBWOOFER 250mm 4Ohm Prima’s compact subwoofer family expands with the introduction of the new 25 cm (10 in.) APS 10 S4S, optimized for enclosures with a reduced volume starting from 10 liters. The configuration of the single 4Ω voice coil makes it ideal to be driven by the new AP F8.9 bit amplifier with built-in DSP that delivers an outstanding 260 W RMS with two channels bridged. Also interesting is the possibility to create custom enclosures with two APS 10 S4S driven by the AP 1D amplifier using the 540 W RMS delivered on the 2Ω load resulting from the drivers connection in parallel. Features - Ultra-low profile (4.7 in. / 120 mm) for maximum installation flexibility. Designed to deliver maximum performance in a sealed enclosure starting from 10 lt. Special designed cone-dustcap-basket geometry which guarantees a long linear excursion capability (11 mm, one-way) while keeping the mounting depth to minimum. Air vents on the basket underneath the spider, eliminating the need for the central pole vent allowing mounting close to rear wall of enclosure. Massive motor assembly, optimized with FEM (Finite Element Modeling) for perfect control under high power, high excursion conditions. Water-repellent treated paper 10 in. cone, featuring a profile developed with FEM simulation and optimized with the Klippel Scan Vibrometer. Single voice coil design specifically developed to be combined with either AP F8.9 bit (2 CH bridged - 260 W RMS) amplifiers taking advantage of the bass boost feature and integrated parametric equalizer of the built-in DSP. Steel mesh grille and plastic gasket included.