Skip to product information
Hertz SP4.900 — Advanced 4-Channel Class-D Motorcycle Amplifier (1,000W RMS / 250W x4 @ 2Ω)
$1,310.00 AUD
SKU: SP4900
| Channels | 4 Channel |
| Power | 1000W RMS |
| Year Range | 1998-2013, 2014-2023, 2024+ |
Hertz SP 4.900 — High-Power 4-Channel Amplifier for Premium Harley Audio Systems
The Hertz SP 4.900 is a flagship high-power 4-channel Class-D amplifier engineered for motorcycle audio systems that demand serious output. With 160 W × 4 RMS @ 4 Ω, 250 W × 4 RMS @ 2 Ω (@ 14.4 VDC, 1% THD), and a weather-resistant IP55 chassis, it’s the preferred choice for SPL-focused Harley Touring builds running high-efficiency speakers at extreme volume.
Key Features
- 160 W × 4 RMS @ 4 Ω (@ 14.4 VDC, 1% THD) — serious power for mid-bass and SPL coaxials.
- 250 W × 4 RMS @ 2 Ω (@ 14.4 VDC, 1% THD) — maximises output for demanding pro-audio speakers.
- Bridged Mode: 500 W × 2 RMS @ 4 Ω (@ 14.4 VDC, 1% THD) for 2-channel high-output setups.
- 3-Channel Mode: 160 W × 2 @ 4 Ω + 500 W × 1 @ 4 Ω, or 250 W × 2 @ 2 Ω + 500 W × 1 @ 4 Ω (@ 14.4 VDC, 1% THD) — a full front stage and a subwoofer from a single amplifier.
- Up to 87% efficient ADC (Advanced D-Class) output stage with a 50 A maximum musical current draw.
- IP55 weather resistance — engineered for open-air motorcycle environments.
- Pre-level and speaker-level inputs (0.6–6 V and 2.2–22 V) with advanced signal management.
- Compact footprint (211.6 × 130 × 49 mm) fits most Harley fairing amp mounts.
Why It Works on Harleys
- Perfect for SPL setups running Hertz SX/SV series speakers at high volume.
- High power delivery overcomes wind, pipes, and open-road noise.
- Stable at 2-ohm loads — ideal for multi-speaker or 4-ohm-per-pair wiring.
- Rugged weather resistance prevents moisture and dust-related failures. Higher-output builds should have their charging capacity and fused power/ground wiring assessed against the complete system.
Recommended System Use
- Front Stage: Drives 6.5″ or 8″ SPL speakers with authority.
- Full Bike System: Run front + rear speakers with strong headroom.
- Front Stage + Subwoofer: 3-channel mode powers a pair of speakers plus a subwoofer from the one amplifier.
- Active Front Stage: Use 2 channels for mids and 2 for tweeters (DSP required).
- Bridged 2-Channel: Ideal for powering mid-bass drivers like SV 200 L.
Fitment
- Engineered for Harley-Davidson Touring motorcycles
- Fits Street Glide, Road Glide, Ultra Limited, CVO, and custom builds
- Compatible with most aftermarket amp trays and mounts
Specifications
| Channels | 4 |
| RMS Power @ 4 Ω | 160 W × 4 @ 14.4 VDC, 1% THD |
| RMS Power @ 2 Ω | 250 W × 4 @ 14.4 VDC, 1% THD |
| RMS Power (Bridged @ 4 Ω) | 500 W × 2 @ 14.4 VDC, 1% THD |
| RMS Power (3-Channel Mode) | 160 W × 2 @ 4 Ω + 500 W × 1 @ 4 Ω, or 250 W × 2 @ 2 Ω + 500 W × 1 @ 4 Ω (@ 14.4 VDC, 1% THD) |
| Total RMS Power | 1,000 W @ 14.4 VDC, 1% THD |
| CEA-2006 Power | 145 W × 4 @ 4 Ω |
| Minimum Load Impedance | 2 Ω (4-channel), 2 + 2 + 4 Ω (3-channel), 4 Ω (bridged) |
| THD | 0.02% @ 1 kHz, 4 Ω, 70% rated power |
| Efficiency | Up to 87% |
| Max Musical Current Draw | 50 A |
| Bandwidth (−3 dB) | 10–35,000 Hz |
| Signal-to-Noise Ratio | 105 dBA |
| Damping Factor | 200 |
| Pre-In Sensitivity | 0.6–6 V |
| Speaker-In Sensitivity | 2.2–22 V |
| Crossovers | HPF / LPF / Full-Range — 50 Hz to 5 kHz @ 12 dB/octave |
| Dimensions | 211.6 × 130 × 49 mm |
| Weight | 2.15 kg |
| IP Rating | IP55 |
Specifications per Hertz published technical documentation.
Need System Advice?
The SP 4.900 is ideal for high-power, multi-amp Harley systems. We can help you match speakers, wiring, charging upgrades, and DSP settings to build a system that performs at the highest level.
Australia Shipping:
- Under $500 → $19.95
- $500–$2,500 → $14.95
- Over $2,500 → FREE
- Bulky items → +$24.95 surcharge (waived over $2,500)
Fast dispatch from Brisbane. Same-day shipping on in-stock orders before 1pm AEST.
Change-of-mind returns: We accept returns within 7 days of delivery on unused, unopened products in original sealed packaging. Restocking fees apply (20–30%). Return shipping is the customer's responsibility.
No returns on opened audio gear, installed items, custom orders, or special-order products. Please check fitment carefully before installing.
Faulty or incorrect items: If you experience an issue, contact us with photos/video and your order number. We'll assess the claim and arrange repair, replacement, or refund for verified faults under the Australian Consumer Law.
Fitment assistance: If you're unsure about compatibility, reach out before ordering—we're happy to help.