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 150 W x 4 RMS @ 4 Ω, 230 W x 4 RMS @ 2 Ω, 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
- 150 W x 4 RMS @ 4 Ω — serious power for mid-bass and SPL coaxials.
- 230 W x 4 RMS @ 2 Ω — maximises output for demanding pro-audio speakers.
- Bridged Mode: 450 W x 2 RMS for 2-channel high-output setups.
- IP55 weather resistance — engineered for open-air motorcycle environments.
- High-level and low-level inputs with advanced signal management.
- Load-adaptive technology ensures stable performance with Harley OEM + aftermarket systems.
- Compact footprint (240 × 131 × 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.
Recommended System Use
- Front Stage: Drives 6.5″ or 8″ SPL speakers with authority.
- Full Bike System: Run front + rear speakers with strong headroom.
- 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 | 150 W × 4 |
| RMS Power @ 2 Ω | 230 W × 4 |
| RMS Power (Bridged @ 4 Ω) | 450 W × 2 |
| Frequency Response | 10–45,000 Hz |
| Signal-to-Noise Ratio | > 100 dB |
| Input Sensitivity | 0.2–5 V |
| Crossovers | HPF / LPF / Full-Range |
| Dimensions | 240 × 131 × 49 mm |
| IP Rating | IP55 |
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.
Shipping
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.
Return policy
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.