Roon’s iOS/Android app seems to have a specification that converts all audio sources to 48kHz. I’d like to request an update so that high-resolution audio is output at its original sample rate.
You mention both iOS and Android.
With iOS devices, via the Lightning port on older iOS devices and USB m-C on newer devices when connected to a DAC it will be lossless for the Roon Arc app and also if you set the iOS device as a typical Roon Endpoint from within the Roon Remote app.
Android devices - not all are equal, but most likely via the Roon Remote app acting as a typical Endpoint it will resemble to 24/48. The Roon Arc app has ‘Enable USB Driver (beta)’ but YMMV here as it doesn’t work for me.
If you are connecting via Bluetooth, then yes both device types will resemble to 24/48 unless you have a high resolution codec enable headphones and a suitable Android device (I can play up to 24/192 with my Bluetooth headphones with my Android device).
