Rolls MX51S Mini Mix 2 Four-Channel Mixer https://a.co/d/48XLqLi
USB to RCA https://a.co/d/iam01Xj
Bluetooth 5.0 Transmitter 3-in-1 https://a.co/d/47TuAMn
I just tried, and I'm able to pair both my Macbook Pro and iPhone to my Linux desktop PC. The PC has Kensington Bluetooth USB dongle. Both the MBP and iPhone can simultaneously play audio over Bluetooth and I can route the incoming audio to a pair of wired headphones. The volume of each stream is independently adjustable via `pavucontrol`.
I also tried pairing a bluetooth headset, but the audio was choppy. Maybe too much bandwidth for 3 devices streaming audio at once? Maybe another dongle would work?
Note that at one point I was experimenting with receiving BT audio on my PC. I can't remember the exact set of configuration changes needed to make this work (if any -- it might've worked out of the box). But the stack is BlueZ + Pipewire on Archlinux.
Pipewire (and Pulse) have a lot of modules and config knobs. Might be possible to get auto-switch working too. They also expose a D-Bus interface, so control from some sort of e.g. Python webapp from your phone is likely.
Try reconnecting it. I have the same problem with my headset sometimes and reconnecting fixes it. My best guess is the implementation of the two Bluetooth modules don't play nice with each other. I have no troubles connecting to a different pc.
The problem was that I had no clue where to even begin to make this setup persistent so I could eventually put it all on a GUI-less RPi, so I gave up.
20 years on and bluetooth still can’t get the ease and reliability of a 50 cent audio cable.
Wanted to have pulseaudio/alsa dmix handling multiple streams/mixing them out with a help of dedicated hardware BT/DAC-ADC-BT path, with a goal to have smart handling of voice calls over music on the go, fake 5.1 in the room, and a voice enhancer / fast rewind for call streams..
Then, Volumio took enough of the raspberry-based hifi market (despite having no bluetooth support, lol) that I've declared these plans no-go as investing in this solely for fun wasn't that enticing, compared to just getting a spare set of equipment to separate work/home audio.
The bad news is the latency which is about 200ms regularly and 40ms with APT Low Latency or 80ms with APT Adaptive. If you go BT > BT RX > BT TX > BT this might be doubled. Both devices will also need to support the same codes and only newer devices support APT Adaptive.
Have a few devices that keep conflicting with one another and acquiring the connection to my bluetooth headset. I have to go through the hassle of navigating to the offending device's bluetooth settings, disconnect it, go to my desired device's settings (which, although it reports it is connected, doesn't actually produce any sound), disconnect it, then reconnect it. Each time.
I'd rather have them all stay connected (maybe one cheap dongle per endpoint) to my rpi and then route to the intended destination with just a press of a physical toggle/key/slider etc, or via phone app.
Additionally would like to be able to simultaneously mix multiple audio sources to the one headset.. oh, and all of this with no latency overhead, please :)