Description of KS-DR1004D: Conformal Coating A conformal coating is a protective chemical coating to safeguard electronic circuits from harsh environments that may contain moisture or chemical contaminants. It provides a barrier to airborne contaminants from the operating environment, such as salt-spray, thus preventing corrosion. Circuit Separation Construction Separated circuit boards of the Pre-amp and Power-amp sections contribute to a reduction in radiation noise. Large LPF Coil The large LPF coil provides a stable, high-quality sound with no distortion even when playing at high volume. Variable HPF & LPF Incorporates a rotary type HPF and LPF which enables fine adjustment. Compared with fixed type switching, more precise sound adjustment is possible to match your preferences. Specifications: Amplifier Maximum Power Output 400W RMS Power Output (4 ohm) [ 1% THD 14.4V] 45W x 4 (20 - 20,000Hz) RMS Power Output (2 ohm) [ 1% THD 14.4V] 45W x 4 (1,000Hz) RMS Power Output (Bridged 4 ohm) [ 1% THD 14.4V] 90W x 2 (1,000Hz) Class Class-D Signal-to-Noise Ratio (reference: 1W into 4 ohms), CEA-2006 Compliant > 82dB Load Impedance Load Impedance Allowance 2 - 8 ohms HPF 50Hz - 200Hz (-12dB/oct) LPF 50Hz - 200Hz (-12dB/oct) RCA Input Ach L/R, Bch L/R High Level Input (Speaker Level Input) Yes High Level Input Auto Power Control (Signal Sensing Turn On) Yes Input Sensitivity 0.2 - 5V Dimensions (W x H x D) 145 x 45 x 99 mm (5-11/16" x 1-3/4" x 3-7/8") Weight 0.7kg (1.5lbs)