How many interfaces are required for Pro Tools HD to function?

Pro Tools HD requires at least one HD series PCI/PCIe card along with compatible interfaces to function effectively. This setup allows Pro Tools HD to leverage the dedicated processing power that comes with these cards, enabling lower latency and higher track counts, which are essential for professional audio production.

The requirement for HD series cards is crucial because they are specifically designed to integrate seamlessly with Pro Tools HD software, providing enhanced performance and reliability. This architecture allows users to connect various types of audio interfaces that are compatible with HD systems, optimizing the overall workflow.

In contrast, other interfaces or modules do not provide the same level of performance or integration that the HD series cards offer, making them less suited for environments that demand high-quality audio processing and real-time performance. Thus, relying on just any interface or module would not meet the rigorous demands that Pro Tools HD is designed to handle in a professional setting.