Phone: Google Pixel 9 Pro (Android 16)
DAC dongle: Realtek USB 2.0 Audio (supports up to 192kHz PCM)
Roon ARC: 1.77 (build 405) earlyaccess
Description of Issue
When enabling the USB Driver beta in Roon ARC, the app fails to initialize exclusive mode with the Realtek USB DAC dongle. Instead of displaying the Android USB hardware permission pop-up, ARC falls back to standard audio routing and Android targets the default (wrong) audio profile, forcing a 192 kHz Qobuz stream to be downsampled to 48 kHz.
After reviewing phone logs withadb shell dumpsys audio_policy and audio_flinger, it appears the Android OS creates the proper high-res hardware profile thread (AudioOut_68D at 192kHz), but it sits idle. Instead, ARC registers an active track under the standard 48kHz mixer thread (SRate: 48000), which looks like a driver initialization failure and silent fallback.
After toggling on “Disable USB audio routing” in Android Developer Options, ARC does not output audio to the USB device and routes audio through the phone’s internal speakers. Switching ARC’s USB beta driver to on or off does not change this behavior.
Self Diagnostic Steps Taken:
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Third-Party Drivers: installed both USB Audio Player Pro (UAPP) and HiByMusic. Both applications successfully trigger the Android OS system permission pop-up (“Allow app to access USB device?”) and can play 192 kHz audio through the USB Realtek dongle.
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Background Tasks: disabled “Now Playing” lock screen, song identification, “Hey Google” voice activation, and Accessibility Services to ensure no concurrent capture streams or flag-stripping policies were active (see AudioPolicyInterfaceImpl.cpp and conditions where SYS_RESERVED_INVALID is not set/used).
Because 3rd party audio drivers from the UAPP and HiBy music players can successfully execute the USB handshake protocol on the phone while Roon ARC does not, I wonder if this is a bug report or regression. I come to this conclusion after reading:
Requesting support to review ARC’s inability to get exclusive control of the USB dongle with the beta driver. Thanks!