3SB Audio

2026-05-10

3SB Controller Overview

3SB Controller is the dedicated Milan controller within the 3SB Audio system architecture.

3SB speakers receive audio via Audio over IP and integrate their own DACs and amplifiers. 3SB Controller sends the rendered audio to those speakers, while DSP remains centralised in the controller rather than running inside each loudspeaker.

The controller software is designed to run on dedicated hardware. The current platform assumptions are:

  • An Intel i210-T1, i226-LM, or IT Ethernet device.
  • A multicore CPU such as an i7 or better.
  • A fanless platform where possible, or alternatively a more generic PC located away from the listening area.
  • A dedicated role, with other software avoided apart from endpoint audio receivers such as RoonBridge, which has already been tested.

That model keeps the user-facing path simple. Music is played to the controller device, which presents itself as an endpoint for common playback standards and then handles DSP, transport, and loudspeaker routing internally.

Additional work is planned around a USB-to-Milan device that presents a DAC-facing interface to the user. That could provide a cleaner source-integration path than relying entirely on software endpoints.

Roon Ready support is also being explored with Roon.

Internally, the controller runs FIR-based DSP and streams the correct audio channels to each speaker.

The standard way of connecting multiple Milan devices is through an AVB-capable switch. Work is underway to support multiport i210 or i226 Ethernet in the controller so that up to four Milan devices can be supported without a switch. That would suit a two-speaker system plus an input DAC particularly well. For now, a small eight-port AVB switch is still required.

The current internal architecture is built from the following layers:

  • Kernel Module: provides input and output audio devices with a common clock for DSP engines.
  • Ingress Handler: adapts user-process audio streams such as Roon into the internal transport path.
  • DSP Engine: provided by CamillaDSP or BruteFIR.
  • Streaming Handler: prepares DSP output for network transport to the speakers.
  • Connection Handler: establishes the controller-to-speaker connections.
  • Streaming Monitor: monitors end-to-end pipeline health and provides both an administrative console view and the user-facing web interface.