The M Series Power Amplifier is a new developed model that achieves a compact size with D-class movement that pursues natural sound. The Final Dividers of the Power Amplifier feature a D-class amplifier composed of MOS-FET. The M-ONE 1ch has 4 para connection, M-SIX is a powerful speaker drive with 2 para connections. The switching device on the power supply is a 2-parallel drive of MOS-FET and is combined with a large troidal transformer high-capacity electrolytic capacitor to create a powerful power supply. (M-ONE / M-FOUR) M-SIX uses MOS-FET 3-parallel drive super strong 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 M-FOUR / M-SIX is compatible with 2-way multi-system etc. (Band pass can be used with M-FOURs 3ch/4ch/5ch/6ch); Features: Compact size width 9.1 x height 2.0 x depth 6.1 inches (230 x 50 x 154 mm) / Subwoofer dedicated amplifier; D-class operation for natural sound; Floating input circuit that keeps ground from loops; Butterworth 1. 2dB/oct Built-in crossover / Equipped with high level input function (equipped with ADEP circuitry to avoid error display when not loading); Auto power-on sensor function (automatically detects the DC voltage of the BTL amplifier and turns on automatically); Idling stop support (maintains operating environment even if the power voltage is low for 5 seconds / 6 V for a short time). [Specifications] Channel mode 1ch output power 240 W x 1 ch 4Ω 41 0W x 1ch 2Ω 600W x 1ch 1Ω Output Operation Class D Class Operation, Frequency Response, 10 - 250Hz, Distortion Ratio, Less Than 0.20% SN, Over 95dB Built-in CrossOver Continuous ON Crossover Frequency/Ramp HP 10 - 50Hz Butterworth 12dBoct (Subsonic) LP 50 - 250 Hz Butterworth Butterworth Butter-250 Hz worth 24dB/oct Bass Boost 25-75Hz/0-+12dB Phase 0---180° Variable Input Sensitivity RCA: 0.5V-6.0V / High Level: 1.1V-13.0V Input Impedance RCA: 20KΩ / High Level: 13Ω Input Mode 1ch/2ch Damping Factor 100+ Pre-Out Supports high level input Includes dedicated 4-pin connector (equipped with ADEP circuitry to avoid error detection during light loads) Auto power on function Support (with high level input) How to confirm compatible H/U remote level controller works when switching LP 5.0 m cable included operating power supply voltage 10.5 V - 16.0 V (supports short power supply voltage drop in 5 seconds/6 V) idling current 0.0.0.0.0 V 65A (No Signal Data: ATO 35A x 2 (side panel), External Dimensions (W x H x D): 6.1 x 2.2 x 9.1 inches (154 x 55 x 230 mm), M-FOUR Same Size, Weight: 4.5 lbs (2.2 kg).