Zapco HB 810 II 8AD — 10-Channel DSP with Hybrid AB + D Amplifier

Zapco HB 810 II 8AD — 10-Channel DSP with Hybrid AB + D Amplifier

The HB 810 II 8AD combines a 10-channel digital signal processor with an eight-channel amplifier that uses two different output topologies in one chassis — four Class AB channels and four Class D channels.

Class AB channels are rated 35 watts RMS at 4 ohms and 50 watts at 2 ohms, with a 100-watt maximum. Class D channels are rated 100 watts RMS at 4 ohms and 150 watts at 2 ohms, with a 300-watt maximum, and can be bridged to 300 watts into 4 ohms across two pairs.

Signal-to-noise is better than 100dB with THD under 0.05%, across a 20Hz to 20kHz bandwidth.

Why Two Topologies

This is the design decision that defines the unit. Class AB and Class D behave differently, and the split assigns each to what it does best.

The four Class AB channels are sized for the front stage — tweeters and midrange, where the topology is traditionally chosen for its behaviour and where 35 watts is ample for drivers reproducing a narrow band.

The four Class D channels carry three times the output and are sized for midbass and subwoofer duty, where efficiency matters because those channels do the sustained work and generate the heat.

Bridging the Class D pairs to 300 watts into 4 ohms gives a genuine subwoofer channel from the same chassis — which the all-Class-AB models in this line cannot do.

Eight High-Level Inputs and Optical

The HB 810 II 8AD accepts eight channels of high-level speaker input — double the rest of the HB II range — plus two RCA inputs, with ten RCA outputs.

Eight high-level inputs matters with modern factory systems, which increasingly split the signal across many channels with different equalisation on each. Capturing all eight lets the processor reconstruct the full-range signal before re-filtering it.

It is also the only model in the line with an optical digital input, alongside Aux, Bluetooth, high level, the app player, and OTG.

Processing Tools

• Equalizer: 31 bands
• Crossover types: Butterworth, Bessel, Linkwitz-Riley
• Crossover slope: 6 to 48 dB/octave
• I/O mixing matrix: yes
• Tuning: PC software and app

System Application

A complete active system from one chassis: three-way front stage on the Class AB channels, midbass and a bridged subwoofer on the Class D channels, all processed across ten channels.

This is the HB II model that does not need an external amplifier to finish the system, which is the practical consequence of the hybrid design.

Installation Considerations

Assign drivers to the correct topology. The Class AB channels are the low-power ones — putting a midbass driver on them and a tweeter on a Class D channel inverts the design intent and wastes both.

Four ohms is the minimum load when bridging the Class D pairs.

Supply voltage is specified 12V to 14.4V. With eight amplified channels drawing from one chassis, size power and ground wire from the fuse rating and the run distance from the battery, and secure the ground to clean bare metal on the frame.

Specifications

• Type: 10-Channel DSP + 8-Channel Amplifier (4 × Class AB + 4 × Class D)
• Power (AB): 35W RMS × 4 @ 4Ω · 50W × 4 @ 2Ω · 100W max
• Power (D): 100W RMS × 4 @ 4Ω · 150W × 4 @ 2Ω · 300W max
• Power (D bridged): 300W RMS × 2 @ 4Ω
• High-level inputs: 8 channels · RCA inputs: 2 · RCA outputs: 10
• Frequency response: 20Hz–20kHz
• THD: <0.05% · S/N: >100dB
• Equalizer: 31 bands
• Crossover: Butterworth, Bessel, Linkwitz-Riley · 6–48 dB/oct
• I/O mixing matrix · PC and app tuning
• Inputs: Aux, BT, high level, player, OTG, optical
• Bluetooth streaming: optional external module
• Input impedance: 20 kΩ (low), 22Ω (high)
• Supply voltage: 12V–14.4V

HF Audio Perspective

The hybrid output stage is the reason to choose this over the rest of the HB II line, and it reflects how systems are actually built rather than how amplifiers are usually sold.

A front stage and a bass section ask different things of an amplifier. Putting Class AB where the front stage lives and Class D where the power and heat are is the same decision a builder would make with separate amplifiers — done inside one chassis, with ten channels of processing tying it together.

Eight high-level inputs and an optical input widen what it can take signal from, which matters as factory systems get more complex. Where a complete active system needs to come from a single unit, this is the one in the line that can actually finish the job.