4-Acoustic ST-6400 Professional Power Amplifier

High-Power 4-Channel Class-D Amplifier

The 4-Acoustic ST-6400 is a flagship 4-channel Class-D power amplifier engineered for the most demanding professional audio applications. Designed for large-scale touring systems, concert venues, stadiums, houses of worship, and high-performance installations, the ST-6400 delivers exceptional output power, outstanding efficiency, and uncompromising reliability.

Capable of producing 4 × 3000W at 2Ω, 4 × 2250W at 4Ω, and 4 × 1500W at 8Ω, the ST-6400 provides enormous headroom for driving line arrays, stage monitors, full-range loudspeakers, and high-power subwoofers. In bridge mode, it delivers an impressive 2 × 6000W at 4Ω or 2 × 4500W at 8Ω, making it an ideal solution for the most demanding sound reinforcement systems.

Powered by advanced Class-D amplifier technology, the ST-6400 combines maximum efficiency with outstanding sonic performance. Its wide frequency response, ultra-low distortion, fast slew rate, and high damping factor deliver tight bass, detailed mids, and crystal-clear highs with excellent loudspeaker control.

The amplifier features professional XLR balanced inputs, four Neutrik NL4 speaker outputs, selectable input sensitivity, intelligent variable-speed cooling, and comprehensive protection circuitry to ensure stable operation under continuous heavy loads. Built into a rugged 2U rack-mount chassis, the ST-6400 is ready for the rigors of touring and permanent installations.

Key Features

• Professional 4-Channel Class-D Power Amplifier
• 4 × 3000W @ 2Ω
• 4 × 2250W @ 4Ω
• 4 × 1500W @ 8Ω
• Bridge Mode: 2 × 6000W @ 4Ω / 2 × 4500W @ 8Ω
• Ultra-low distortion (THD ≤0.06%)
• High damping factor (>450:1) for precise loudspeaker control
• Wide frequency response (10Hz–34kHz ±0.3dB)
• High signal-to-noise ratio (>100dBA)
• Selectable input sensitivity (0.775V / 1V / 1.5V / 2V)
• Professional balanced XLR inputs
• Four Neutrik NL4 speaker outputs
• Intelligent variable-speed cooling system
• Advanced protection against overload, short circuit, thermal, RF, ultrasonic, DC faults, and clipping
• Standard 19-inch, 2U rack-mount chassis

Technical Specifications

Output Power

• 4 × 3000W @ 2Ω
• 4 × 2250W @ 4Ω
• 4 × 1500W @ 8Ω

Bridge Mode

• 2 × 6000W @ 4Ω
• 2 × 4500W @ 8Ω

Audio Performance

• THD+N: ≤0.06%
• Frequency Response: 10Hz – 34kHz (±0.3dB)
• Slew Rate: >60V/μs
• Damping Factor: >450:1
• Signal-to-Noise Ratio: >100dBA
• Channel Separation: >70dB
• Voltage Gain: 45dB

Connectivity

• Inputs: Balanced XLR
• Outputs: 4 × Neutrik NL4 Speaker Connectors

Controls

• Front Power Switch
• Independent Front Gain Controls
• Rear Input Sensitivity Selector
• Rear Operating Mode Selector

LED Indicators

• Signal (-30dB / -10dB)
• Signal (-4dB)
• Clip
• Protect
• Power
• Bridge Mode

Protection

• Short Circuit Protection
• Thermal Protection
• Overload Protection
• DC Fault Protection
• RF Protection
• Ultrasonic Protection
• Open Circuit Protection
• Reactive Load Protection
• Power Supply Shutdown

General

• Amplifier Class: Class-D
• Operating Voltage: 220V ±10%, 50/60Hz
• Rack Size: 19-inch / 2U
• Dimensions: 483 × 470 × 88 mm
• Net Weight: 25.5 kg

Ideal Applications

• Large Concert Systems
• Touring Productions
• Professional Line Array Systems
• Stadiums & Arenas
• Houses of Worship
• Convention Centers
• Rental Companies
• Nightclubs
• High-Power PA Systems
• Permanent Audio Installations

The 4-Acoustic ST-6400 is built for professionals who require maximum power, exceptional reliability, and uncompromising sound quality. Its advanced Class-D design, high output capability, and comprehensive protection make it the ideal amplifier for powering today's most demanding professional loudspeaker systems.

Tags: 4-Acoustic ST6400, ST-6400 amplifier, 4 channel power amplifier, Class D amplifier, professional amplifier, touring amplifier, concert amplifier, line array amplifier, PA amplifier, live sound amplifier, rack amplifier, installation amplifier