Rebec RPX-B1680 – 16-Channel Class D DSP Amplifier for Advanced Multi-Channel Car Audio Systems

Product Overview

The Rebec RPX-B1680 is a high-channel-count DSP amplifier from Rebec’s RPX-B Series, combining 16 channels of Class D amplification with 16 channels of low-level DSP output in a single integrated platform.

Its architecture is designed around extensive channel capacity. Sixteen independently amplified channels allow complex multi-way speaker systems to be powered and processed from one DSP amplifier, while sixteen low-level outputs provide additional flexibility for integration with external amplification.

The RPX-B1680 also introduces a different processing platform within the RPX-B range, using dual ADAU1452 DSP processors and a PCM1681 DAC, together with 31-band EQ, PC-based tuning and multiple analog and digital source inputs.

16-Channel Class D Amplification

The Rebec RPX-B1680 incorporates 16 channels of Class D amplification, with the same rated output available across every channel.

At 14.4V and 4Ω, the amplifier provides:

50W RMS × 16CH at 0.1% THD.

At 3Ω, rated output increases to:

66W RMS × 16CH at 0.1% THD.

Maximum output is specified at 100W ×16CH at 4Ω and 130W ×16CH at 3Ω, measured at 10% THD.

Rather than dividing the amplifier into different power groups, the Rebec RPX-B1680 maintains a uniform output architecture across all sixteen channels. This simplifies channel allocation when building systems containing many independently amplified loudspeaker sections.

According to the current specification, bridged operation is not supported.

Sixteen Channels for Complex System Architecture

The defining characteristic of the Rebec RPX-B1680 is its channel capacity.

Sixteen amplified channels significantly increase the number of loudspeakers that can be controlled and powered independently from a single device.

This becomes particularly relevant in complex active installations where tweeters, midrange drivers, midbass drivers and other loudspeaker sections are assigned their own amplifier and DSP channels.

The factory information specifically identifies the RPX-B1680 as providing more channels and more power than the RPX-B1260, with greater flexibility for installing and configuring multi-channel or Atmos-style car audio systems.

The exact allocation of those sixteen channels can be determined according to the actual loudspeaker layout rather than being restricted to a predefined configuration.

16-Channel DSP Output

The processing architecture matches the scale of the amplifier section.

The Rebec RPX-B1680 provides 16 low-level output channels at 2.2V.

This means the sixteen DSP channels are not restricted to the built-in Class D amplifier. Processed signals can also be routed to external amplifiers whenever the system requires a different type of amplification or additional power for a particular speaker section.

The RPX-B1680 can therefore operate as a highly integrated 16-channel DSP amplifier or serve as the signal-processing center of a larger multi-amplifier installation.

Dual ADAU1452 DSP Processing

One of the most important technical characteristics of the Rebec RPX-B1680 is its DSP platform.

The processor uses two ADAU1452 DSP chipsets, providing the processing architecture required for its extensive multi-channel configuration.

DSP operation is specified at a 48kHz sampling frequency, with a dynamic range of 93dB.

For system tuning, the RPX-B1680 provides 31-band EQ, giving installers detailed frequency adjustment capability across the system.

The crossover section supports Butterworth, Linkwitz and Bessel filter types, allowing different crossover characteristics to be selected according to the tuning requirements of individual speaker sections.

The processor also provides six presets for saving and recalling tuning configurations.

All DSP adjustment is performed through PC software.

PCM1681 DAC and ES7210 ADC

The Rebec RPX-B1680 combines its dual ADAU1452 DSP processors with a PCM1681 DAC chipset and ES7210 ADC.

This differs from several other RPX-B models using the AP5688 and CJC4344 architecture.

The current specification lists a frequency response of 20Hz–20kHz, with a signal-to-noise ratio of 95dB.

Total harmonic distortion is specified at below 0.08% for low-level signals and below 0.09% for high-level signals.

Together, the dual DSP processors, DAC and ADC form the signal-processing architecture behind the RPX-B1680’s sixteen-channel system.

16-Channel High-Level Factory Integration

The input architecture has also been expanded to match the larger number of channels.

The RPX-B1680 provides 16 high-level inputs supporting 7.9–24.9Vpp.

This allows the processor to receive a large number of speaker-level signals from compatible factory audio systems, which can be particularly useful when integrating with vehicles using complex multi-channel OEM audio architectures.

Two low-level analog inputs supporting 1.3–5.1Vpp are also available.

Combined with sixteen amplified outputs and sixteen low-level outputs, this gives the Rebec RPX-B1680 extensive channel capacity from input through processing to output.

Digital Source Connectivity

The Rebec RPX-B1680 provides several options for direct digital audio input.

Both Optical (Toslink) and Coaxial support signals up to 192kHz/24-bit.

A dedicated USB Audio input is also provided.

For wireless playback, the unit integrates Bluetooth 5.4.

These options allow the DSP amplifier to work with compatible digital playback sources in addition to factory high-level and analog low-level signals.

Integrated Architecture for Large Multi-Channel Systems

Despite its extensive channel count, the Rebec RPX-B1680 integrates processing and amplification into a single chassis measuring approximately 192 × 263 × 52 mm.

Operating voltage is specified at 10–16V, with a standby current of 1.5A and maximum current of 130A.

By combining sixteen amplifier channels and sixteen-channel DSP processing in one unit, the RPX-B1680 can reduce the number of separate components required for installations involving a large number of independently controlled speakers.

At the same time, its sixteen low-level outputs preserve the flexibility to introduce external amplifiers where the system design requires them.

High Channel Capacity with Uniform Power Distribution

The Rebec RPX-B1680 is fundamentally designed around channel capacity and system flexibility.

Its 16 × 50W RMS Class D architecture at 4Ω provides uniform amplification across sixteen independent channels, while sixteen low-level outputs allow the DSP platform to remain useful even when external amplification is incorporated.

The combination of dual ADAU1452 DSP processors, PCM1681 DAC, ES7210 ADC, 31-band EQ, multiple crossover filter types, six presets, 192kHz/24-bit Optical and Coaxial inputs, USB Audio and Bluetooth 5.4 provides the processing and connectivity required for sophisticated multi-channel installations.

For car audio systems that require many independently processed and amplified loudspeaker channels, including more complex multi-speaker and Atmos-style configurations, the RPX-B1680 provides a highly integrated platform without relying on exaggerated power claims or unnecessary complexity.

Rebec RPX-B1680

16-Channel Class D DSP Amplification with Dual ADAU1452 Processing for Complex Multi-Channel Car Audio Systems.