Number of channels: 4 channels Maximum power: 400W (100W × 4 @ 2 Ohms) RMS power: 50W × 4 @ 4 Ohms Signal to noise ratio: 90 dB Total Harmonic Distortion (THD): 0.05% Dimensions: Width 9.8 inches × Height 2.3 inches × Length 7.7 inches