I tried several different searches and figure this info already exists. So, if it does please direct me to that thread or resource.
After trying three different UPnP players, I finally found one (JRiver) that will play two DLNA linked devices simultaneously which was a big "Yeah!". The best way I have found so far is to just have both live in Overview, have the same playlist loaded on both and then just start them both as close together as possible. That gets them within about a second of each other.
I tried using the link function but had two issues: 1. They didn't seem to stay perfectly in sync 2. The worst problem was that I started getting 1-2 seconds of silence every couple minutes which was too annoying to ignore. So, I unlinked them and that stuttering problem went away.
Somewhere in my exploration of MC 21 I thought I saw a "Party" function but could not find anything on that doing several searches either and now don't see it in any of the menus.
Any advice on running 2 and preferred 3 devices simultaneously so I could have the same music on systems downstairs, upstairs and outside would be much appreciated.
Thanks in advance!