4-Acoustic ST-4400 Professional Power Amplifier

High-Power 4-Channel Class-D Amplifier

The 4-Acoustic ST-4400 is a professional 4-channel Class-D power amplifier engineered for demanding live sound, touring, fixed installations, and multi-zone audio systems. Combining high-output performance with exceptional efficiency, the ST-4400 provides reliable power distribution across four independent channels, making it the ideal solution for driving full-range speakers, stage monitors, line arrays, and subwoofers.

Delivering up to 4 × 2000W at 2Ω, 4 × 1500W at 4Ω, and 4 × 1000W at 8Ω, the ST-4400 offers outstanding flexibility for professional audio applications. When higher output is required, bridge mode provides 2 × 4000W at 4Ω or 2 × 3000W at 8Ω, making it suitable for high-power speaker systems.

Designed with advanced Class-D amplifier technology, the ST-4400 delivers clean, dynamic sound with ultra-low distortion, excellent transient response, and superior loudspeaker control. Its high damping factor ensures tight, accurate bass, while the wide frequency response reproduces every detail with clarity and precision.

The ST-4400 is equipped with intelligent cooling, selectable input sensitivity, professional XLR inputs, Neutrik NL4 speaker outputs, and comprehensive protection circuits that guard against short circuits, thermal overload, clipping, DC faults, RF interference, and mismatched loads. Built into a rugged 2U rack-mount chassis, it is ready for continuous operation in the most demanding professional environments.

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Key Features

• Professional 4-Channel Class-D Power Amplifier
• 4 × 2000W @ 2Ω
• 4 × 1500W @ 4Ω
• 4 × 1000W @ 8Ω
• Bridge Mode: 2 × 4000W @ 4Ω / 2 × 3000W @ 8Ω
• Ultra-low distortion (THD ≤0.06%)
• High damping factor (>450:1) for excellent speaker control
• Wide frequency response (10Hz–34kHz ±0.3dB)
• High signal-to-noise ratio (>100dBA)
• Selectable input sensitivity (0.775V / 1V / 1.5V / 2V)
• Four professional Neutrik NL4 speaker outputs
• Balanced XLR inputs
• Intelligent variable-speed cooling fan
• Complete protection circuitry for reliable long-term operation
• Standard 19-inch, 2U rack-mount design

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Technical Specifications

Output Power

• 4 × 2000W @ 2Ω
• 4 × 1500W @ 4Ω
• 4 × 1000W @ 8Ω

Bridge Mode

• 2 × 4000W @ 4Ω
• 2 × 3000W @ 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: 43dB

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
• Load Mismatch 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: 23.0 kg

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Ideal Applications

• Concert Sound Systems
• Touring Productions
• Rental Companies
• Line Array Systems
• Stage Monitor Systems
• Houses of Worship
• Hotels & Convention Centers
• Nightclubs
• Multi-Zone Audio Installations
• Professional PA Systems

The 4-Acoustic ST-4400 is designed for audio professionals who need the flexibility of four independent amplifier channels without compromising power or sound quality. Its advanced Class-D design, professional connectivity, and comprehensive protection make it an excellent choice for demanding live sound and installation applications.

Tags: 4-Acoustic ST4400, ST-4400, 4 Channel Amplifier, Class D Amplifier, Professional Power Amplifier, Concert Amplifier, Touring Amplifier, Live Sound Amplifier, PA Amplifier, Rack Amplifier, Installation Amplifier, Neutrik NL4, Professional Audio Equipment