2011 Mac Mini with Multiple Display Outputs for Sound?

[mbhforum]

Hey guys...

I have a Mid-2011 Mac Mini with two monitors, one is connected straight HDMI, the other is connected via an HDMI->Thunderbolt Display adapter. I'd like to get sound working on both monitors at the same time (individually, I can alternate HDMI output between them). I tried going to Audio Midi Setup and creating an aggregate device or multi-output device and neither worked.

I suspect the issue might be I am trying to use multiple HDMI connections at the same time? Do I need to try using VGA -> Thunderbolt adapter instead?

 

[treekram]

I can't offer a definitive solution but I can offer advice on what probably won't work.

From what I can see, the OS (Sierra and El Capitan, in my case) doesn't treat HDMI and DisplayPort as different. So, for example, on my computer, it sees the speakers on monitor as a DisplayPort audio device even though I'm connecting via HDMI (the monitor can do either HDMI or DisplayPort). Likewise, on my 2012 Mini, my 2014 Mini and my mid-2012 MBP, the System Information doesn't report a connection type. In your case, I'm pretty sure it thinks your monitor connected to the Mini-Displayport port is a Displayport monitor, not a HDMI monitor. So, I don't think there's an issue with multiple HDMI monitors connected.

You'll notice that I refer to the port as Mini-Displayport, not Thunderbolt. There's a 99.99% chance that your adapter is converting the Displayport signal to HDMI, not the Thunderbolt signal to HDMI. You can check that by seeing if there are any Thunderbolt devices in the System Information app. This is a minor point, but clarifying that may help to avoid confusion as you research the issue.

If your point to wanting to try VGA is to not have the display audio for that monitor as an option (using the built-in output instead), then that may work. VGA doesn't carry audio.

Are you trying to play two different audio sources, one on each monitor? I'm presuming the same audio source on two monitors. I haven't tried that so again, I can't offer a solution, but the Audio MIDI Setup seems the way to go. When you press on the "+" button at the bottom of the window, and select "Create Aggregate Device", do both of your monitors show up as choices?

 

[mbhforum]

I can't offer a definitive solution but I can offer advice on what probably won't work.

From what I can see, the OS (Sierra and El Capitan, in my case) doesn't treat HDMI and DisplayPort as different. So, for example, on my computer, it sees the speakers on monitor as a DisplayPort audio device even though I'm connecting via HDMI (the monitor can do either HDMI or DisplayPort). Likewise, on my 2012 Mini, my 2014 Mini and my mid-2012 MBP, the System Information doesn't report a connection type. In your case, I'm pretty sure it thinks your monitor connected to the Mini-Displayport port is a Displayport monitor, not a HDMI monitor. So, I don't think there's an issue with multiple HDMI monitors connected.

You'll notice that I refer to the port as Mini-Displayport, not Thunderbolt. There's a 99.99% chance that your adapter is converting the Displayport signal to HDMI, not the Thunderbolt signal to HDMI. You can check that by seeing if there are any Thunderbolt devices in the System Information app. This is a minor point, but clarifying that may help to avoid confusion as you research the issue.

If your point to wanting to try VGA is to not have the display audio for that monitor as an option (using the built-in output instead), then that may work. VGA doesn't carry audio.

Are you trying to play two different audio sources, one on each monitor? I'm presuming the same audio source on two monitors. I haven't tried that so again, I can't offer a solution, but the Audio MIDI Setup seems the way to go. When you press on the "+" button at the bottom of the window, and select "Create Aggregate Device", do both of your monitors show up as choices?

Yes, I see 2 HDMI outputs as choices and I tried to create an aggregate of them, but still no dice. The goal is to have the same audio source play on both monitors at the same time, creating a better overall sound.

 

[treekram]

So I tried this using a monitor and a headphone (I don't have a 2nd monitor with speakers) and using the "Create aggregate device" won't output to both devices simultaneously, however, the "Create multi-output device" does. Initially, the multi-output device wasn't selected in the Sound options in System Preferences. If you run software which allows you to select the audio output device (like VLC), you should check that "System Sound Output Device" (what showed up on my computer in VLC) is selected as well. So if that doesn't work, there may be an issue with your monitors. I'm running Sierra.
[doublepost=1520824007][/doublepost]Oh ... By the way, once (if) you setup multiple devices like this, you can't use the system volume control.