Cardia DSP

Cardia is the DSP and conversion project that underpins routing, crossover, delay, equalisation, phase management, and multichannel transport across the current portfolio.

Design Considerations

The platform has to balance several variables simultaneously:

• Sample rate strategy across 44.1/48 kHz families and higher-rate operation.
• Bit depth and host-audio format support.
• Operating-system compatibility across macOS, Windows, and Linux.
• Interface and transport choices such as USB, PCIe, Dante, AVB, or AES67-class networking.
• Channel density, FIR length, and the software environment used to run the filters.

Conversion Strategy

The current architecture prefers a single high-density DAC over synchronised groups of smaller DACs. That keeps timing, routing, and systems integration simpler in a 30-channel deployment.

An audio-over-IP approach was selected so playback, capture, and control devices can be decoupled and routed more flexibly than a single fixed hardware endpoint allows.

Related Linux transport-layer work is tracked separately in Linux AVB/Milan.

Current Stack

• RME M32 DA Pro
• RME Digiface AVB
• RME AVB control tooling

Dante, AES67/Ravenna, and AVB-based alternatives were all evaluated, including Tascam ML32. AVB, and increasingly Milan-oriented deployment assumptions, became the more practical direction for the current software and system requirements. The transport layer remains an active area of evaluation as Linux-capable network-audio options continue to mature.