User Reviews Send this to a friend · Kenwood eXcelon KAC-X521 – Amplifier – 2-channel … Variable Low-Pass Electronic Crossover: 50 – 200Hz, 24dB per Octave; LCD Display: Voltage/Current/Temp/Cooling Fan Speed/A.M.S. Adjustment Value; 2- Ohm Stable; Cooling Fan: 2 (2-Speed); Copper-Shielded EE Core Transformer; Large Secondary Capacitors; Large Toroidal Noise Suppression Filter; Microprocessor-Controlled Operation; Power Input Terminals: Gold-Plated, Large Screw-Type; …