DS18 PRO-SPL8.5K1 8,500 Watts RMS SPL Subwoofer Class D Monoblock Amplifier Engineered in the US, manufactured in South Korea, and independently tested vs. competing amplifiers, the smoothness, color, and design are just the cherry on top of the amazing technology and quality control these amps feature. With MOSFET PSU transistors, unbalanced RCA inputs, full range RCA outputs, variable input level control and a thermal, over-load, output direct, and speaker short circuit four-way protection circuit. Use to power the best subwoofers in the market. WATTS POWER @4-OHMS: 2300 RMS @14.4V. 2700 RMS @16V. 3300 RMS @18V. WATTS POWER @2-OHMS: 4300 RMS @14.4V. 5300 RMS @16V. 6500 RMS @18V. WATTS POWER @1-OHM: 8500 RMS @14.4V. 9000 RMS @16V. 9600 RMS @18V. WATTS POWER @4-OHMS LINKABLE: 9000 RMS @14.4V. 10000 RMS @16V. 11000 RMS @18V. WATTS POWER @2-OHMS LINKABLE: 14000 RMS @14.4V. 17000 RMS @16V. 19000 RMS @18V. 750A Fuse. 30-250Hz Variable Low. 0-12dB Bass Boost. 30-90Hz Bass Boost Frequency. &lt;0.15% THD. &gt;100dB StN Ratio. 10-350Hz Frequency Response. 10-70Hz Subsonic Frequency. 1-Ohm Impedance. 9-18 Operating Voltage. 90% Efficient. 0-180 Degree Phase Shift Control. 10V-0.2V Input Sensitivity