I want to be able to airplay from my phone to a given speaker in the house and have them broadly in sync (doesn't need to be millisecond accurate, but enough th

I want to be able to airplay from my phone to a given speaker in the house and have them broadly in sync (doesn't need to be millisecond accurate, but enough that's it's not jarring when I go from one room to another). And I can. It's not rocket science.