Hertz SP1.900 — Compact 1-Channel Class-D Motorcycle Subwoofer Amplifier (1,000W RMS @ 1Ω)

Hertz SP 1.900 — 1000 W Mono Amplifier for Harley Subwoofer Systems

The Hertz SP 1.900 is a high-power mono Class-D amplifier engineered for motorcycle subwoofer systems that demand serious output. Delivering 1000 W RMS at both 2 Ω and 1 Ω (@ 14.4 VDC, 1% THD), and built in an IP55 weather-resistant chassis, it is the ideal sub amplifier for Harley-Davidson Touring models running Tour-Pak or saddlebag subwoofers.

Key Features

• 1000 W RMS output @ 1 Ω or 2 Ω (@ 14.4 VDC, 1% THD) — regulated design for consistent performance.
• Stable at 1 ohm for flexible wiring of multiple subwoofers.
• IP55 water and dust resistance for motorcycle environments.
• Subsonic filter (fixed at 25 Hz @ 24 dB/octave) protects shallow enclosures and prevents over-excursion.
• Low-pass crossover (50–250 Hz, fixed at 24 dB/octave) for clean subwoofer integration.
• Compact chassis (211.6 × 130 × 49 mm) fits Harley fairings and Tour-Paks.
• High-level and low-level inputs for full compatibility with factory and aftermarket head units.

Why It Works on Harleys

• Ideal power match for shallow subs like the Hertz MPS 250 S2/S4.
• Consistent 1000 W output (@ 14.4 VDC, 1% THD) delivers strong low-end even with wind and road noise.
• Compact, rugged chassis withstands heat, vibration, and moisture.
• Flexible wiring options suit single or dual subwoofer configurations.

Recommended System Use

• Subwoofers: MPS 250 S2, MPS 250 S4, CS 250 S4
• Ideal Power: 800–1000 W RMS per sub system
• Low-Pass Filter: adjustable 50–250 Hz, slope fixed at 24 dB/octave (80–120 Hz is a sensible starting point for most Harley sub enclosures)
• Subsonic Filter: fixed at 25 Hz @ 24 dB/octave — not adjustable

Electrical Requirements

• High-current amplifier — expect significant power draw at full output.
• Maximum Current Consumption: 50 A @ 14.4 VDC into minimum load (Hertz published figure).
• Fusing: Hertz does not publish a fuse rating for the SP 1.900, and a fuse protects the cable rather than the amplifier. The correct fuse therefore depends on the cable gauge and run length used in your specific install, not on the amplifier alone — confirm the value with your installer before you wire it up.
• Wiring: 0 AWG or 4 AWG depending on cable length.
• Charging Note: Big subwoofer systems may require a high-output stator and/or a secondary battery.

Fitment

• Designed for Harley-Davidson Touring motorcycles
• Fits fairings, Tour-Paks, side compartments and custom amp racks
• Compatible with factory and aftermarket head units

Specifications

Specifications per Hertz published technical documentation.

Need Subwoofer System Design?

Matching the SP 1.900 to the right sub, enclosure volume, and wiring configuration is critical. We can help you build a hard-hitting sub setup tailored to your Harley.