I've been using JRiver Media Center for years, many years . . . and just discovered ZONES! I have both hi-res and regular CD quality files in my music library of about 23,000 tracks. There are times when i sit down with my headphones connected through my DAC and headphone amp. There are other times when i like having my music play throughout the house with airplay. The problem is that when you use air play, hi-res files are unlistenable. Airplay only handles resolutions up to 48k and i have a lot of tracks with 88k, 96k and 192k and Media Center plays them and sends them out into the ether via Airplay which then mangles the sound of those hi-res files badly.
The solution: I made one zone for airplay and my iMac speakers, and another separate zone for listening on my DAC/headphones. In the DAC/headphone zone, i have the Format box unchecked under Options->Audio->Settings->DSP & output format. In the Airplay/iMac speakers zone, i have that box checked and then i have set the format changes as in the picture attached to this post.
One more tweak i forgot to include: In each zone, open the Options->Audio->Audio Device->Device Settings and be sure that Open Device with exclusive access is unchecked for both zones, and that Integer Mode is checked for your hi-res DAC zone and unchecked for your Airplay zone.
Doing this lets me listen to hi-res files over my DAC/headphones or i can to choose to listen to music throughout the house via airplay, or on my iMac speakers without it ending up mangled. JRiver Media Center is very powerful. I just wish there were tutorials on how some of the more esoteric features worked so i could have discovered this a few years ago.
Thank you for this great app for Macs.