The Alpine SPS-406 Coaxial Car Speaker system is a compact (4 by 6 inches) solution for your car audio needs. The wide frequency response of these Alpine speakers (93 Hz to 22 kHz) reproduces both highs and lows from your favorite tunes. With a nominal power of 45 Watt RMS and a maximum output of 140 Watt RMS, the Alpine SPS-406 Coaxial Car Speaker set allows you to use an amplifier to get the most of your car audio experience. The 2-way domes of these Alpine speakers provide clarity at all volume levels, with a sensitivity of 87 dB that reduces distortion.