I set up MPD+PulseAudio streaming as described in Streaming Audio to Multiple Wireless Speakers. It worked perfectly with 2 remote wireless speakers, but then my wifi network was brought to its knees. Further research indicates that, while PulseAudio RTP works splendidly on wired networks, it is known to be extremely problematic on many wifi setups. I was able to get both remotes streaming from MPD over http, but they were a second or two out-of-sync, giving a prison yard PA effect.
I've reviewed other answers here on SE, but the linked pages aren't clear on wifi performance. I'd like to ask if anybody has a working, tested streaming solution for playing synchronized audio to multiple remote speakers over wifi. I'm game for trying again, but would rather not take down my network!