You’re looking at it the wrong way around, I’m afraid: you don’t choose Roon in the audio settings in your Mac’s preferences, but you will need to enable and select your Mac’s output in Roon, via Settings > Audio.
Can you post a screenshot of what you see when you open Settings > Audio on your iMac?
This 
Under Networked…it shows ZERO DEVICES! When I click on the ADD Networked Device…my only option is “HQ player”
NOTHING ELSE is listed on that page!
Plus I cannot figure out how to get an actual screen shot on my iMAC!
Is anyone still looking in to assisting me ??? I posted over 2 hours ago…looking to get this fixed…I guess I’m spoiled by previously quick replays.
Thanks,
Larry
Larry, that screenshot - is there only a “Networked” section shown in the Audio settings, or have you just scrolled down to show only the Networked section?
You should have two other sections showing in the Audio settings:
Your screenshot shows “Larrys-Mac-mini” at the top by the Settings header. This will be your Mac mini where your Roon Server Core is running.
Your iMac, which you are using as a Roon Remote device, should have its audio devices listed in the “Connected to this PC” section. That’s where you enable audio output on your iMac - not under the Networked devices section. Unless you have Roon Bridge software running on other devices in your network, you won’t see anything listed ïn the Networked section.
Hey Larry,
Yes, you’ve been spoiled a bit… 
The absence of of the ‘Connected to this Mac’ and ‘Connected to Core’ options in your audio settings indicates most likely that the RAATServer process is blocked on your iMac.
Can you double-check that the firewalls on both machines are off? Do you run other software that may provide firewall functionality?
Rene,
Your answer baffles me. How could either computer be blocked/firewalled if Roon shows up on my Office iMAC from my Mac mini?
Hi Larry!
The Roon Process and the RAAT process are two different system processes. A firewall can let 1 through but still block the other. Take a look at the background processes snippet from my Windows computer.
That is why I always suggest just turning all the Firewalls off completely as a quick test to see if that is the issue. If Roon then works, then we can describe how to have the Firewall running and let each process through.
Roon has two main processes: Roonserver (obviously) and RAATserver (which handles the audio stuff). Both must be able to communicate between core and remote or zone.
The fact that the audio devices on your core and remote are MIA could indicate that RAAT cannot communicate – the easiest way to eliminate this is to (double)check that no firewall on either system is running.
I checked both computers Security Firewall and they are both turned off.
My iMAC has a hard-wired Ethernet connection and the Mac mini is wireless …anything?
Dang this is driving me crazy.
Another question is When I click the Configure button to finding OS devices…It does not do a thing!!!
The “searching for devices” logo never stops!
Hi Larry,
Can you describe your Wi-Fi setup ? Roon uses multicast and UDP as well as TCP/IP. Any settings in switches or routers that block those will create detection/play issues in Roon.
That is because you don’t have any Roon OS machine on your network. Roon OS is a specialized operating system available either embedded in a product you have purchased or a machine on which you have loaded the OS. The end user Roon OS has not yet been released but is also known as ROCK. When this is released, you will download the OS onto a USB key, insert it into a machine built with the specified hardware (Intel NUC based) and run the install program. Reboot and voila! instant RoonServer machine.
Hi Larry,
That is a very helpful screenshot. It shows that the RoonServer has recognized your iMacs internal system output. My first comment is to disable all non-essential audio output which will not be used.
My second comment is to give audio output not disabled each a unique name so there is no confusion.
So, try renaming the Built-in Output uner Connected to this Mac something like TEST1. Then go the audio zone picker and choose TEST1 to be the output zone. Then try playing some music.
Andy,
I have a MAC Airport that sends WiFi around the house…I get excellent reception. So how do I check that out?
My iPad shows both my Mac mini and my iMAC…I could send a screen shot of that.
One thing I noticed using server over standard Roon. When I got RoonServer running it says it takes over my Mac mini and “all other windows will not be able to be accessed”.
I only saw that once. I still see the Roon logo in the upper menu bar but it no longer takes over my Mac mini…?
I deleted all the Roon folders and re downloaded RoonServer again…no difference…? ;-(
Here is a shot from my iPad that shows it recognizes the iMAC. I can bring up Roon click play and it’s playing music somewhere just not on my iMAC??? Not on my Mac mini either…???
Larry: please follow @Rugby’s advice above: rename the two zones on your iMac (shown as System Output and Built-In Output under Connected to this Mac) to something different (say iMac System Output and iMac Built-In Output) and do the same for the zones that show under Connected to Core (name them Mini System Output and Mini Built-In Output) – so you can be certain you are playing to the right zone.
Now change the zone you are playing to by clicking on the speaker icon in the black play bar at the bottom of the screen. Choose ‘iMac Built-In Output’ or ‘iMac System Output’. Play some music.
What happens?
Nevermind – follow @Rugby’s advice below – it basically comes down to the same. I was a few seconds earlier, but his has pics.
I think maybe you are getting confused on the difference between the Settings/Audio section and the Output Zone selector which are in different places. In Settings/Audio you are 1. enabling or disabling the available audio output. If you disable the output, all that does is not make it available in the Output Zone selector. And, 2. you can change playback settings for the audio device.
I consider it best practices to disable all audio output zones except for the ones you will really select to play music. This removes clutter on the Output Zone selector. Additionally, it is best practice to always give each output a unique name.
So, the first suggestion is to disable all the audio zones which are highlighted in yellow. Which means in the end, the only available (ie. not disabled) Built-in Output would be the one circled in blue. The other one (under Connected to Core, should be disabled, for now).
Once you have the audio outputs disabled And the only Built-in Output choice is the one on the iMac, then you need to open the Output Zone selector to tell Roon which audio device you want to send your music to.
In the close up of your other screen shot, I have circled the area to click to access the Output Zone selector. In the screenshot, you are playing music to the Yggdrasil output.
If you click on that you will get a list of all available (i.e. not disabled) audio zones. See my screen shot of my zone selector:
To play to a different zone, click on that zone and verify that the blue selector dot is there. Then go to your music, select something and click play.
