I’m starting a running program with my family. Part of the fun is building a shared playlist and listing to cues together. I’d like to run the audio off one phone and have it go simultaneously to 4 headsets. I see there’s phone apps that do today but my kids don’t have phones. Is there a hardware device that can do this?
Auracast is basically what you’re after but not out yet. I think a couple of transmitters and a headphone splitter is your best bet. There are products like this but you need to use their headphones and figure out power for the transmitter. It is USB C though, looks like a power bank would work.