Zapco Harmony HB 104D II 4-Channel Full-Range Class-D Micro Power Amplifier

Compact Power & Clarity: Zapco Harmony HB 104D II

Upgrade your in-car listening experience with the Zapco HB 104D II full-range Class-D amplifier. Combining a space-saving micro chassis with robust power performance, this 4-channel unit delivers 100W x 4 RMS @ 4Ω and 140W x 4 RMS @ 2Ω, with bridging capabilities up to 280W x 2 RMS @ 4Ω—making it a perfect choice for upgrading door speakers or running a 3-channel front stage + subwoofer setup.

Key Features & Highlights

• High-Efficiency Class-D Output: Delivers 560W RMS total power with low heat dissipation and high efficiency in a compact footprint.

• Flexible Output Configurations: Delivers 100W x 4 @ 4Ω, 140W x 4 @ 2Ω, and bridges to 280W x 2 @ 4Ω.

• Seamless Integration: Features both RCA Low-Level and High-Level Speaker inputs for easy connectivity to factory radios or aftermarket head units.

• Variable Crossover Control: Integrated electronic crossovers allow fine-tuning with selectable High-Pass (HPF) and Low-Pass (LPF) modes.

• Micro Form Factor: Measures just 180 mm x 115 mm x 45.5 mm, fitting effortlessly under seats or behind trim panels.

Technical Specifications

• Brand: Zapco

• Series: Harmony Blue

• Model: HB 104D II

• Amplifier Topology: Full-Range Class D

• Channels: 4-Channel

• RMS Power Output @ 4 Ohm: 100 Watts x 4

• RMS Power Output @ 2 Ohm: 140 Watts x 4

• Bridged Power Output @ 4 Ohm: 280 Watts x 2

• Frequency Response: 20 Hz – 20,000 Hz (±1dB)

• Signal-to-Noise Ratio (S/N): > 90 dB

• THD + Noise: < 0.1%

• THD @ Rated Power: < 0.5%

• Input Sensitivity: 0.25V – 6.0V (Low-Level RCA)

• Input Types: RCA Low-Level & Speaker High-Level Inputs

• Crossover Control: Variable Electronic High-Pass / Low-Pass Crossovers

• Dimensions (L x W x H): 180 mm x 115 mm x 45.5 mm (7.08" x 4.52" x 1.79")

Frequently Asked Questions

Can I connect the Zapco HB 104D II to my factory head unit without a Line Output Converter?

Yes! The HB 104D II includes built-in High-Level speaker inputs, allowing direct connection to OEM factory stereo speaker wires.