Budget... How tight is tight? If you can stand about 1/2 second
latency, I have been using Mumble for years now.
Full duplex single
channel great audio fidelity. 5 musicals a year 500+ seat
venue. We run on some cast off pc thin clients running raspberry pi desktop, a RP3+ as server, and some nice logitech DECT headsets that let us wander up to 300 feet from each
base depending on walls
etc. deff covers the whole theater and
lobby reliably. Easy to set up if you dont try to get too fancy. We just grab the
headset off it's charger
base.. and go. Thin clients can be had in the 30 to 50 buck range. Logitech dect headsets about 70-100 on the used market. Can use bluetooth headsets as well, or hard wired. (really cheap) Any old pc even a decade or more old can be your server/
hub, and you can even cut in a
cell phone in a pinch with the mumble app and wifi Everything is set to auto reboot in case of a
power outage.. I have it all on 2
UPS battery backups to avoid hiccups.