Roon > Dirac Live Processor > Stereo Phantom Golds

Now that Dirac offers a standalone version of DiracLive, I managed to do my measurements and produce a filter for Dirac Live Processor (DLP) on the MacMini where Roon Server resides.

From Roon you need to establish a virtual connection using AudioHijack to the Mac’s Digital Out. I use an optical connection to Devialet Dialog, which is connected with the Phantoms by ethernet. The AudioHijack window shows this:

Application: Roon > AU: DLP > Output Device: Digital

Both, the AudioHijack window as well as the AU-DLP window show the sound indicators, but those in the DLP window are very low, indicating relatively low amplitude.

In Roon I set volume to DSP-volume and I can regulate volume from within Roon and from the Phantom Remote.

However, there seems to be glitch in my volume settings that is perhaps the cause of the low amplitude shown in the AU-DLP window. The consequence is that when I switch to another app, such as AppleMusic, I get too high a volume from the Phantoms.

I am at a loss and don’t know how to configure the chain for a decent volume level for all apps.

I will add how this problem was solved to spare others the unpleasant experience.

When you play music through this chain all of the elements have a potential contribution to the final volume. So when you have a remote control for your Phantoms (either physical or an app on your phone) check the following items one by one. Be sure to turn down the remote and stop the music in Roon.

  1. In Roon set the device volume control to fixed.
  2. In Audio HiJack: Set the AudioUnit for Dirac Live Processor (DAP) to max or a bit below the max for safety.
  3. Start Dirac Audio Processor (the real one, not the AU) and set the volume to max or close to max.
    The problem is that the real DAP reduces the volume of its AU without this fact being reflected in the slider setting of the AU. That is, AU may still show max, while the music is low because the real DAP is not on max.
  4. Mac Audio settings: set Dirac Virtual Audio Device to max in the sound settings.
  5. Control volume entirely from your Phantom remote.

Even Dirac support (not to mention AudioHiJack support) doesn’t mention this interdependence between real DRP and its AU. They should get to know their own recommendations better.

Otherwise, Dirac’s effect on the quality of reproduction is overwhelming. Be sure to give it a try.