Stetsom HL 400x4 2 Ohms – Compact 4-Channel Digital Amplifier | 400W RMS

Overview

Meet the Stetsom HL 400x4, a compact digital amplifier built to deliver multi‑channel capability without sacrificing space. Its Mosfet Class D design prioritizes efficiency and cool operation, while remaining stable at 2 ohms. This model is capable of up to 400W RMS (13.8V) with a 420W RMS peak when voltages rise to 14.4V, giving you ample headroom for a clean, full‑range sound across four channels.

Designed for tight installations, the HL 400x4 pairs a small footprint with adaptable tone controls, so you can tailor the output for front stage, rear fill, or sub‑bass emphasis. While individual results depend on your overall system and setup, you’ll find a versatile balance between power, control, and reliability in a compact form factor.

Power, controls, and tone

• 400W RMS (13.8V) and 420W RMS peak at 2 ohms
• 4-channel Mosfet Class D amplifier, full-range stable at 2 ohms
• Crossover controls: HPF & LPF at 90 Hz for channels 1–2; Bass boost 30 Hz–74 Hz up to +14 dB for channels 3–4
• Flat mode disables internal adjustments for installation-ready operation
• High input capability supports flexible connections with head units and line‑level sources

Design, cooling, and installation

• Compact, efficient cooling system supports longer sessions and safe operation
• Power/ground connectors sized at 6 mm²; remote 0.75 mm²; speaker wiring 2.5 mm²
• Fuse 25A, recommended within 30 cm of the battery for protection

Real-world use

In real‑world installs, the HL 400x4 fits tight spaces while offering precise channel control and dependable cooling. Potential benefits include cleaner highs, controlled bass, and efficient power delivery when paired with compatible sources and speakers. Actual results depend on the rest of the system and setup choices.