Weak HDMI audio from 2013 Mac Pro

[jw2002]

I just bought a refurbished 2013 Mac Pro from Apple to replace a 2009 Mac Mini, and I noticed that the sound level through HDMI is at least 40 dB WEAKER than when I use the digital optical-out cable. I am connecting to a Denon DN500-AV.

I also notice that the Mac Pro is always piggybacking an audio signal on the HDMI, even when I go into System Preferences -> Sound -> Output and select Digital Out in place of HDMI. As a result, this is causing the receiver to attempt to use the (weak) HDMI audio and ignore the correct digital optical-out audio. Is there any way to force the Mac Pro to not do this piggy backing of audio onto HDMI?

Thanks.

 

[ActionableMango]

I don't know about OS X, but can't you configure the DENON to use the optical in as the audio source for the HDMI input?

I've used Yamaha and Onkyo receivers, and in both cases for every input you could manually assign that input's audio source.