Roon ARC on iOS shows playback is 24bit/44.1kHz when it is actually to a Bluetooth device using AAC. I imagine ARC is outputting a 24bit lossless stream to an iOS framework that is handling the Bluetooth output, but for a screen that is intended to transparently display the audio chain it should consider up to the DAC output, in this case including the Bluetooth encoding.
iOS doesn’t expose the internals of the BT encoding stage to apps. ARC can’t display data the framework doesn’t receive from the operating system.
ARC’s underlying architecture doesn’t function quite like Roon. The latter displays each stage of the Signal Path, including granular DSP and iconographic objects to represent hardware stages. ARC focuses on the precise DSP applied within the app. Since Zones aren’t a feature in ARC at this time, these iconographic elements aren’t there.
If you’d like to submit a Feature Suggestions for ARC’s Signal Path to include greater precision, there’s active discussion about changes to these features behind the scenes.
