The DRX-4 combines accurate, noise-free signal processing with high-current power for dynamic speaker control. The result is pure, rich and authentic sound. Integra's dynamic audio amplification delivers 110 Watts per channel with 35 amps of high instantaneous current capability. The DRX-4 is certified Select2 Plus by THX. THX spends 40-60 hours testing over 2000 data points ensuring that the DRX-4 is capable of meeting rigorous audio and video performance standards for reference level, distortion free playback and includes THX loudness plus technology to bring out intricate details at lower listening levels.