The 1200S is Infinity's latest Reference subwoofer offer incredible installation flexibility. Their low-profile design allows them to fit perfectly into even the most shallow of enclosures great for today's compact cars. Polypropylene woofer cones deliver exceptional bass response at frequencies as low as 27Hz. But what makes these subs really stand out is their Harmanproprietary SSI (Selectable Smart Impedance), which allows the subwoofer to present the amplifier with either a 2 or 4 ohm load at the flip of a switch.