miniDSP SPK-4P: A Compact PoE+ Speaker Built Around Networked Audio and DSP

The miniDSP SPK-4P is not just a small active speaker with a network socket. Its appeal lies in how several normally separate parts of an audio system have been brought together: networked audio transport, power delivery, digital signal processing, and amplification. Using a single RJ45 Cat5/6 Ethernet cable, the SPK-4P can receive power, stream audio, and be controlled as part of a larger system. For installations or desktop-style systems where cable management, synchronization, and configuration flexibility matter, that integration is the central idea behind the product.

A compact active speaker with fewer system boxes

At 125 x 125 x 131 mm and 1.3 kg, the SPK-4P is physically compact, but its architecture is closer to a small networked audio endpoint than a conventional powered speaker. It is an active speaker, meaning amplification is built in, and it also includes digital processing that can be configured through miniDSP’s software. That reduces the need for separate amplifiers, external DSP hardware, and additional signal-routing hardware in suitable systems.

The practical advantage is simplicity. A conventional multi-speaker setup can quickly become a collection of signal cables, power supplies, amplifiers, and control interfaces. The SPK-4P is designed around a more streamlined model: one Ethernet connection can carry audio, power, and control when PoE+ is used. For users planning a clean installation, a multi-speaker network, or a compact system where space is limited, that approach can be genuinely useful.

Single-cable PoE+ operation

One of the SPK-4P’s most distinctive features is Power over Ethernet Plus support. With PoE+, the speaker can be powered via the same RJ45 Ethernet cable used for AVB audio and device control. This is especially attractive in spaces where running separate AC power to every speaker position is inconvenient or visually undesirable.

The speaker also supports a 12 VDC supply through a 5.5/2.1 mm DC input, rated at 45 W. That gives the system designer or owner another option when PoE+ infrastructure is not available, or when a conventional DC power arrangement is preferred. Output power is specified as 2 x 12 W when running on PoE+ and 2 x 15 W when powered from a 12 V supply. The distinction matters because it makes clear that the speaker is designed to work in both network-powered and externally powered scenarios, with output dependent on the power method used.

AVB networking for synchronized audio

The SPK-4P uses Audio Video Bridging, or AVB, for networked audio. In this design, AVB is powered by an XMOS XCore200 processor, described as a 500 MHz USB/AVB processor. The purpose of AVB in this context is to deliver uncompressed, synchronized audio streams between speakers in a network with very low latency.

That matters most when multiple speakers need to operate together. In a distributed or multi-channel system, synchronization is not a luxury; it is part of making the system function correctly. If speakers receive audio at different times, the result can be timing errors and an inconsistent presentation. AVB is included here to address that requirement at the transport level, making the SPK-4P more than a stand-alone powered speaker with an Ethernet input.

The use of Ethernet also gives the SPK-4P a different installation profile from many compact speakers that rely only on analog, USB, or consumer wireless connections. It is better understood as a networked audio component intended for structured, configurable systems.

Onboard DSP for configuration and acoustic adjustment

miniDSP is strongly associated with digital signal processing, and the SPK-4P reflects that emphasis. The speaker uses a 32-bit floating point Analog Devices SHARC ADSP21489 processor running at 400 MHz. According to the documented feature set, this processor handles signal processing functions including equalization, filtering, and acoustic correction.

The available DSP settings include FIR filters, IIR EQ, gain, level, and delay. These tools are important because they allow the speaker to be adapted to a particular system layout or acoustic requirement rather than being fixed in a single operating mode. Delay can help align speakers in time; gain and level control assist with matching output across channels; EQ and filtering can support tuning and integration work.

Access to these elements through miniDSP’s software is another key part of the product’s usefulness. Instead of requiring a separate hardware processor or relying solely on physical controls, the SPK-4P is designed for software-based configuration. For users comfortable with DSP, that opens the door to more precise system setup than a typical compact active speaker would allow.

Integrated amplification and master-slave flexibility

Amplification in the SPK-4P is handled by Class D technology, specifically a multi-level switching audio amplifier design developed by Merus Audio. The speaker is specified to deliver 2 x 15 W when powered by 12 VDC, or 2 x 12 W when powered by PoE+. The dual-channel amplifier arrangement is significant because each SPK-4P can act as an amplifier for two speakers in a master-plus-slave configuration.

That master-slave capability adds flexibility. Rather than requiring every speaker in a small system to include a complete electronics package, one SPK-4P can drive a second speaker. In installation terms, that can simplify system design and reduce the number of powered network endpoints needed, depending on the layout. It also makes the SPK-4P more adaptable than a single-channel active speaker that can only power itself.

The amplifier power figures position the SPK-4P for compact and controlled applications rather than large-room, high-output duties. Its strengths are integration, control, and networked deployment, not the replacement of high-power amplification in demanding large-scale listening rooms.

Connectivity suited to both networked and direct sources

The documented inputs include one optical Toslink input and one RJ45 Ethernet AVB input. The RJ45 connection is the central interface for the speaker’s networked identity, carrying AVB audio and, when used with PoE+, power and control. The optical input broadens the speaker’s usefulness by allowing connection to a digital source that provides Toslink output.

This combination gives the SPK-4P two distinct roles. It can operate as part of an AVB-based speaker network, where synchronization and Ethernet infrastructure are central. It can also accept a more familiar optical digital connection in setups where a direct digital input is useful. The presence of both inputs helps the speaker bridge specialist networked audio and more conventional digital audio environments.

Who the miniDSP SPK-4P is most suitable for

The SPK-4P is best suited to users and installers who value compact hardware, networked audio, and configurable DSP. It makes particular sense where multiple speakers need to be synchronized over Ethernet, where running separate power cables is undesirable, or where detailed software-based adjustment is part of the plan. Small commercial installations, desktop systems, education spaces, control rooms, and distributed audio environments are all examples of contexts where its design priorities may be relevant, provided the system requirements match its capabilities.

It is also well suited to technically inclined owners who appreciate access to FIR filters, IIR EQ, gain, level, and delay settings. Those tools are valuable, but they are most useful when the user understands what needs to be adjusted and why. Someone seeking a purely traditional passive loudspeaker, a simple plug-and-listen analog speaker, or a high-power main speaker for a large listening space may not be the natural audience for this product.

The SPK-4P’s strengths are not about visual luxury or maximum output claims. They are about clean system architecture, signal control, compact size, and the convenience of combining AVB, PoE+, DSP, and amplification in one small speaker platform.

Conclusion

The miniDSP SPK-4P stands out for its unusually integrated approach: AVB network audio, PoE+ single-cable operation, onboard SHARC-based DSP, Class D amplification, and master-slave speaker support are all built into a compact active design. Its most compelling qualities are flexibility, synchronization, software configurability, and installation simplicity. It is ideally aimed at users or system designers who want a small networked speaker with serious DSP tools and cleaner cabling, rather than those looking for a conventional passive speaker or a high-power full-size hi-fi loudspeaker.