Sign In

The Sundown Audio SFB‑1000.4D 4‑Channel Full‑Range Class D Amplifier brings serious power and flexibility for vehicle audio systems where space, efficiency and output all matter. With high current capability and a full feature set including variable crossovers, bass boost, and protection circuits, this amp is ideal for driving mid‑range speakers, coaxials or even multi‑channel subwoofer setups.

This unit is brand new, factory‑sealed and ready for installation into an aftermarket system. Its Class D design keeps size and heat down while enabling high power output and efficient operation.

Key Benefits

• Delivers up to 1050 W × 4 channels at 1 Ω, 590 W × 4 at 2 Ω, or 350 W × 4 at 4 Ω — giving you headroom and flexibility across a variety of speaker loads.
• Full range capability with variable high‑pass and low‑pass filters (15 Hz‑6 kHz / 50 Hz‑6 kHz) plus bass‑boost functionality, enabling fine tuning of your system.
• Built‑in protection mechanisms (thermal, voltage, speaker short, DC offset) and a “Smart Cooler” fan system help ensure reliability in demanding installs.
• Compact and efficient: the dimensions ~10.5″ × 9″ × 2.75″ make it easier to mount in tight spaces while still delivering high output.

Technical Specifications

• Channels: 4
• RMS Output (approx):
• 350 W × 4 @ 4 Ω (14.4 V)
• 590 W × 4 @ 2 Ω (14.4 V)
• 1050 W × 4 @ 1 Ω (14.4 V)
• Input Sensitivity: 200 mV
• Signal‑to‑Noise Ratio: ~100 dB
• Frequency Response: 10 Hz – 20 kHz (‑3dB)

Installation & Compatibility

The SFB‑1000.4D is suited for multi‑channel speaker systems (for example, front and rear door speakers) or multi‑subwoofer builds where four channels of high power are needed. Install it in a well‑ventilated space, use proper gauge power and ground wiring (per manufacturer and wire‑kit recommendations), and set gains and crossovers according to your speaker setup. Because this amplifier can deliver very high power, ensure your vehicle’s electrical system (battery, alternator, ground) is up to the task. Professional installation is recommended for optimal performance and system reliability.

FAQS

• What is the Sundown Audio SFB 1000.4 used for?
  It’s a 4-channel amplifier designed to power mids, highs, and full-range speakers efficiently.
• Is the SFB 1000.4 reliable for daily use?
  Yes, it’s known for stable operation and strong performance in everyday audio builds.
• Does the SFB 1000.4 include protection circuits?
  It features voltage and thermal protections to help prevent damage.
• Where can I buy the Sundown Audio SFB 1000.4?
  Livewire Audio offers Sundown amplifiers with fast nationwide shipping.