If I use ARC on an iPhone, and run a BTR3K over Bluetooth, will I get a true lossless path? It supports a lot of formats: AAC/SBC/aptX/aptX LL/aptX HD/LDAC. But I don’t know how it will connect. Appreciate any input. Also, what it depends on and potential limits, eg on bit depth etc. Thanks!
AFAIK no as there are no lossless audio codecs for Bluetooth.
A typical sender/receiver situation. The question is what the sender supports too. I think for music the two devices will then choose the highest quality standard/codec known to both. Connect the two and you can probably lookup the connection parameters/options used/available for that connection on your phone.