What does the rule of thumb state regarding sample rate and available channels?

The correct understanding of the relationship between sample rate and available channels is that as the sample rate increases, the number of channels you can utilize decreases. This is primarily due to the limitations of bandwidth and processing power within digital audio systems. Higher sample rates require more bandwidth because they lead to more data being transmitted per unit of time. Since each channel consumes bandwidth, when the sample rate is doubled, the overall system can accommodate fewer channels.

Therefore, when you double the sample rate, you effectively reduce the number of available channels by half to maintain optimal performance and quality of the audio signal. This principle is crucial for audio engineers and network designers to understand, as it helps in making informed decisions regarding the configuration of digital audio networks like Dante, ensuring compatibility and efficiency when scaling audio systems.