The D-ONE Final Dividers are MOS-FET 3-parallel drive with fast switching speed, high power and heavy sound. D-FOURs Final Dividers feature a bipolar transistor TO-3P which is popular for sound quality, and are push-pull connection with AB class for natural sound. Both D-ONE/D-FOUR models have 2 parallel power supply switching devices, combined with a large troydal transformer and large capacity electrolytic capacitor to create a powerful power supply. Convenient built-in crossover High Pass or Low Pass (band pass) can be set between high pass 15 - 4 KHz / low pass 40 - 4 KHz and D-FOUR is compatible with 2-way multi-system etc. D-ONE can be set to a band pass from 10 to 250 Hz. In addition, it has a bass boost function (45Hz/0 to +12dB). Compatible with all models, high level inputs, and can connect speakers output such as factory decks. Equipped with newly developed ADEP circuitry to prevent error detection during light load of genuine head units. It greatly eliminates the hassle of connecting dummy resistors, etc. Protection works with high speed protection function in case of abnormalities such as thermal, overload, or short-circuit. [Features] High-grade housing (W x H x D): 12.6 x 2.0 x 9.1 inches (320 x 52 x 230 mm); 62 W x 4 ch (when in 4 Ohm stereo); Adopts AB class operation with natural sound; Floating input circuit to prevent error display when not loaded. Auto power-on sensor. Equipped with function (automatically detects DC voltage of BTL amplifier) [Specifications] Channel mode 2ch/3ch/4ch; Output power 65Wx4ch; 4Ω stereo; 90Wx4ch; 2Ω stereo; 180Wx2ch; 4Ω bridge; Output part operation class; AB operation; Frequency characteristics: 10-50KHz distortion rate or less than 0.0 Hz SN. Ratio 108 Over dB Internal CrossOver HP/LP Switching Type (3 ch/4 chBP Configurable), Crossover Frequency/Slop, HP 15 - 4.0 KHz, Butterworth 12 dB/oct Fixed, Bus Boost, 45 Hz/0 - +12 dB (C/D Channel), Input Sensitivity RCA: 1.0 V - 6.0 V 0V / High Level : 2.5 V - 14.0 V Input Impedance: RCA: 30 KΩ / High Level: 12 Ω Input Mode: 2 ch/4 ch Damping Factor, 65 or higher High Level Input, Dedicated Connector Included (Equipped with ADP Circuit to Avoid Error Detection During Light Loads), Auto Power-On Function, Compatible H/U Detection Method of Operating Power Supply Voltage 9. 6V-16 .0 V Idling Current: 0.75A (with no signal), Internal Fuse, ATO 25A x 2, External Dimensions (W x H x D): 9.1 x 2.0 x 12.6 inches (230 x 53 x 320 mm), Weight: 7.7 lbs (3.2 kg)