XDi 600.4 - Arc Audio 4-Channel 600W RMS 1200W Max Class D Car Amplifier XDi 600.4 - Arc Audio 4-Channel 600W RMS 1200W Max Class D Amplifier 4 Channels at 4 ohms: 150 Watts | 4 Channels at 2 ohms: 150 Watts | 2 Channel at 4 ohms: 300 Watts Frequency Response: 20Hz - 20kHz Bass Boost: 12dB@45Hz (Front Only) Dimensions:9.020 (L) x 6.268 (W) x 2.162 (H)