Hertz SP 4.900 Motorcycle Amplifier | 1000W RMS 4-Channel Harley & Bagger Audio Amp

If you're building a Harley Davidson motorcycle stereo system that can be heard clearly at highway speeds, the Hertz SP 4.900 motorcycle amplifier delivers the power, efficiency, and reliability serious riders demand.

The Hertz SP 4.900 is a high-output 4-channel Class-D motorcycle amplifier delivering 1000 watts RMS, designed specifically for Harley Davidson bagger audio systems, touring motorcycles, and powersports vehicles where installation space is limited but performance is critical.

Part of the Hertz SPL Show Series, this amplifier combines high efficiency, advanced signal integration, and rugged IP55 weather-resistant construction to withstand the vibration, moisture, and extreme conditions that motorcycle audio systems face.

Whether you're upgrading the stereo in a Harley Street Glide, Road Glide, Electra Glide, or custom bagger, the SP 4.900 provides powerful clean audio capable of driving high-efficiency motorcycle speakers even at 70 mph riding speeds.

If you're building a complete system, explore our full collection of:

Motorcycle Audio Collection

Hertz SP 4.900 compact 4 channel motorcycle amplifier for Harley Davidson bagger audio systems

What the Hertz SP 4.900 Motorcycle Amplifier Is

The Hertz SP 4.900 is a compact high-power 4-channel motorcycle amplifier engineered for Harley Davidson touring motorcycles and powersports audio systems where space, heat, and vibration are major challenges.

Delivering 1000 watts RMS total output, the amplifier provides the clean power necessary to drive:

• Harley fairing speakers
• saddlebag speakers
• bagger audio upgrades
• full motorcycle stereo systems

Unlike many compact motorcycle amplifiers, the SP 4.900 features Universal Speaker Simulators (USS) which allow the amplifier to integrate with factory Harley Davidson radios and aftermarket head units without triggering speaker load errors.

This allows riders to upgrade their Harley audio system while maintaining factory radio controls and functionality.

Browse additional motorcycle amplifiers here:

Motorcycle Amplifiers Collection

Hertz SP 4.900 IP55 weather resistant motorcycle amplifier aluminum chassis

Why Riders Choose the Hertz SP 4.900 Amplifier

Motorcycle audio systems face unique challenges that traditional car audio systems do not.

Wind noise, road vibration, open-air acoustics, and limited installation space require amplifiers that deliver maximum power with exceptional efficiency.

The Hertz SP 4.900 motorcycle amplifier was engineered specifically for these conditions.

Key advantages include:

• 1000 watts RMS total output for loud, clear audio at highway speeds
• Compact chassis designed for Harley fairings and saddlebag installations
• High-efficiency Class-D amplifier technology reducing heat and power draw
• IP55 weather-resistant aluminum chassis for outdoor riding environments
• Factory radio compatibility via Universal Speaker Simulators (USS)
• Flexible 4-channel or bridged configurations for different system builds

When paired with high-efficiency motorcycle speakers, the SP 4.900 provides the clean power needed to maintain clarity and volume while riding.

Key Features of the Hertz SP 4.900

• 1000W RMS high-output motorcycle amplifier
• Advanced Class-D amplifier design with approximately 85% efficiency
• IP55 weather-resistant aluminum chassis
• Universal Speaker Simulators for factory radio integration
• Flexible 4-channel / 3-channel / bridged configuration
• Compact chassis ideal for Harley bagger installations
• Signal-to-Noise Ratio of 105 dBA for extremely clean audio output
• Built-in thermal, overload, and DC protection circuits

Technical Specifications

Power Output

160W × 4 @ 4Ω
250W × 4 @ 2Ω
500W × 2 bridged @ 4Ω

Total Output

1000W RMS

Audio Performance

Frequency Response
10Hz – 35kHz

Signal-to-Noise Ratio
105 dBA

Total Harmonic Distortion
< 0.02% @ 1kHz

Damping Factor
200 @ 1kHz

Input Sensitivity

Pre-In
0.6 – 6V

Speaker Level Input
2.2 – 22V

Dimensions

8.33" × 5.12" × 1.93"

Weight

4.74 lbs

Rear connections and controls on Hertz SP 4.900 motorcycle amplifier

Who the Hertz SP 4.900 Is Best For

The Hertz SP 4.900 motorcycle amplifier is ideal for riders building high-output Harley bagger stereo systems while maintaining a compact amplifier footprint.

This amplifier is commonly used for:

• 4-speaker Harley bagger audio systems
• fairing speaker + saddlebag speaker setups
• Harley touring stereo upgrades
• high-power motorcycle stereo systems
• compact amplifier installs in baggers

Because of its power-to-size ratio, the SP 4.900 is one of the most popular Harley Davidson amplifier upgrades available.

Compatible Harley Davidson Models

The SP 4.900 is commonly installed in:

• Harley Street Glide
• Harley Road Glide
• Harley Electra Glide
• Harley Ultra Limited
• custom Harley bagger builds

Browse compatible speakers here:

Motorcycle Speakers Collection

Best Speaker Pairings for the SP4.900

To achieve maximum performance, the SP 4.900 amplifier is commonly paired with high-efficiency motorcycle speakers, such as:

• Hertz SX 690 NEO saddlebag speakers
• Hertz SX 165 NEO fairing speakers
• Hertz HSP Harley audio system kits

These combinations create powerful Harley bagger stereo systems capable of delivering clear music even at highway speeds.

Installation & Fitment

Installing a motorcycle amplifier requires proper wiring, mounting, and system tuning to achieve optimal performance.

Typical installation steps include:

• amplifier power wiring and fuse protection
• RCA or speaker-level signal inputs
• speaker wiring integration
• amplifier mounting and vibration protection
• crossover and gain tuning

Because motorcycles have limited installation space and constant vibration, correct amplifier mounting and wiring protection are essential.

If you're new to motorcycle audio systems, our guide explains how amplifiers, speakers, and radios work together:

Motorcycle Stereo Systems Explained

Watch the Hertz SP 4.900 Installed in a Harley Audio System

Real installation videos help riders understand how compact motorcycle amplifiers integrate into Harley Davidson bagger stereo systems.

You can also explore more motorcycle builds on the Stereo Installs YouTube channel.

Professional Harley Davidson Stereo Installation in Mentor, Ohio

Stereo Installs specializes in motorcycle stereo installation and Harley Davidson audio upgrades for riders throughout Northeast Ohio.

Our shop installs:

• motorcycle speakers
• motorcycle amplifiers
• Harley bagger audio systems
• complete motorcycle stereo upgrades

Visit our shop:

Stereo Installs
7471 Tyler Blvd Ste B
Mentor, Ohio 44060

Call us:

(440) 525-2001

or Get a Quick Quote here.

Serving riders across:

Mentor, Willoughby, Painesville, Cleveland, Lake County, Northeast Ohio

Learn more about our installation services:

Frequently Asked Questions

Will the Hertz SP 4.900 work on a Harley Davidson?

Yes. The compact design and weather-resistant chassis make it ideal for Harley bagger audio systems and touring motorcycles.

Does this amplifier work with factory Harley radios?

Yes. The built-in Universal Speaker Simulators (USS) allow the amplifier to integrate with many factory Harley Davidson stereo systems.

Is the Hertz SP 4.900 waterproof?

The amplifier has an IP55 weather-resistant rating, protecting it from dust and water spray for outdoor motorcycle environments.

How powerful is the SP 4.900?

The SP 4.900 delivers 1000 watts RMS total output, making it one of the most powerful compact motorcycle amplifiers available for Harley bagger stereo systems.

Shop Motorcycle Amplifiers & Harley Audio Upgrades

If you're building a louder Harley Davidson bagger stereo system, the Hertz SP 4.900 motorcycle amplifier delivers serious power, reliability, and efficiency in a compact amplifier platform.

Browse more motorcycle amplifiers and Harley audio upgrades here:

Motorcycle Amplifiers Collection