Low-profile design: Because today’s compact cars offer less space, the Infinity Reference Subwoofers are designed to fit into small enclosures. They’re slim, sleek, stylish, and don’t sacrifice on sound. Harman-proprietary SSI (Selectable Smart Impedance): Unlike most dual-voice coil woofers, which provide either 1 or 4 ohms or 2 or 8 ohms, the Infinity Reference Subwoofers give the listener 2-ohm and 4-ohm, providing the two most often used impedances. Frequency response 27Hz -175Hz: Your audio is filled with delicious sounds. Unfortunately, you’re not always hearing them all. With lows that dig down into the depths of 27Hz, you’ll hear the low-end frequencies you’ve been missing. OEM-level reliability testing: Infinity tests every speaker to the same rigid specifications as automakers, subjecting them to extreme conditions that break lesser speakers. We freeze them, blast them with ultraviolet light and drive them at full power. Peak power handling: 1000W, Nominal impedance: 2 ohm or 4 ohm, switch selectable, 92dB Sensitivity