echo•mux: a self-hosted multi-room Bluetooth audio streamer with per-speaker latency alignment and Spotify Connect support

Hey everyone! A couple of weeks ago, I was lying in bed, listening to Spotify, looking around at my mix of premium and budget Bluetooth speakers from different brands, and thought: “Why can’t I just stream to all of these simultaneously?” As a long-time developer, I thought I could for sure solve this somehow with the hardware I already own, and did my research. I found the industry goes towards Wi-Fi-based systems, Sonos and whatever, but I love my new Edifiers, my old Sony, and my Sackit (anyone remember