Got a Mid 2010 Mac Mini plugged into a Meridian HD621 using HDMI. The HD621 goes into a 568.2mm. When I use the TIDAL app directly, TIDAL outputs 2 channel stereo over the HDMI. The 568 reports “MHR Mus2 88k”. However when I play the same track using Roon, the 568 reports “MHR Mus6 88k” (which means 5.1 signal). The sound is 2 channel coming over as 2 channels of a 5.1 signal. The 568 is unable to use the 2 channel presets (like trifield) or mix the bass into the subwoofer.
I have tried setting the HDMI output to 2.0 in Roon. Tried non-exclusive mode. The “Send stereo as 5.1” is not checked. No luck. The signal still shows up as Mus6. I’m running the HDMI CoreAudio in exclusive mode. When I run the TIDAL app I run that in exclusive mode also.
To be clear, I’m not looking for upmix. The expected behavior should be that 2.0 channel source material is sent as 2.0 channels over HDMI, so that it shows up as Mus2, like it does when using the TIDAL app.Then the 568 can use its 2.0 channel presets.
Thanks.
I am assuming there are a very small number of people that use Tidal and 2 channel HDMI in this way - I am one of them however. I have never noticed whether my NAD 390DD amp differentiates between HDMI audio from Roon and the Tidal app as you describe. Interesting that the difference is occurring for you though.
Ok, what you have in MIDI Audio Config? Its very strange situation (different stream from apps in same hardware conditions, with appropriate settings)…
Have you enabled the “Use Exclusive Mode” option in Tidal? You can configure this by clicking on the “More Settings” button that appears next to the “Sound Output” text in the Tidal app.
In addition, I would check the Apple Audio MIDI Setup application to see what format support the device is reporting back to the operating system. You can find this program in your Applications > Utilities folder. When you select the HDMI output, there should be a dropdown menu next to the text “Format”. This drop down menu will show all of the reported supported formats of the device. If the device supports 2ch and 6ch signaling, they will both appear in the menu. Here is an example from a 2ch only device
According to the Meridian documentation, the device can change how many channels it reports during the HDMI handshake using the Meridian MConfig app. You can read more about it here
Ok, so just read the HD621 manual you supplied. Says that I can configure the HD621 to advertise how many channels it supports. I clearly do not want to advertise only 2, since then my blu-ray player wont send 5.1.
Also, the TIDAL app works, with the exact same configuration, and manages to supply 2.0.
I apologize for the delay in getting back to you, we have been discussing this issue internally as well as performing some testing of our own.
The QA team asked if it would be possible for you to use the MConfig app to temporarily force the device to 2ch mode and see if you are able to get Roon to send the 2ch stream to the device. This will help us figure out where in the playback chain is causing Roon to send the 6ch stream to the device. We appreciate your patience as we work on this issue and we continue to investigate how we can get this working for you.
Thanks for getting back to me. This weekend I received an Oppo 203 which I’m using instead of the HD621 setup. I’ve got the Oppo 203 with a vanity board, so it drives my speakers directly. And it’s Roon Ready! I went this route as the 568 was bad, so I no longer have a way to test the 621 I’m afraid. I’d be more than happy to set it up for testing but without the 568 I can’t hear the sound coming out of it. I’d could plug it in, and do the MConfig, without sound, if that would help. You need a log dump?
Now I have the problem of upmix. The oppo doesn’t have any processing at all, so stereo is only coming out of the FL and FR speakers. Does Roon have a plugin architecture? Can I write an upmix plugin? Honestly, just playing stereo L/R out of all the L/R channels in a 5.1 or 7.1 system would be fine for me. I don’t need the .1 or the center.
Unfortunately, the Oppo UDP-203 only supports two channel audio on its Roon Ready networked input. However, if you are able to use the HDMI input, you should be able to configure things in the way you have described using Roon’s Procedural EQ in the DSP Engine. I just tested using a MacBook Pro and the Oppo UDP-203 we have in house, I’m able to get any of the channels mirrored to other outputs successfully. I have included a screenshot below of how the procedural EQ should be set up for the Oppo in 7.1 mode and mirroring the left and right channels on surround back left and surround back right respectfully.
I’m not familiar with your setup in detail, but if you are just looking for an extra line-level output to feed your subwoofers, an RCA Y-Adapter/Splitter should achieve what you are looking for without having to resort to upmixing or DSP solutions.
That works! Ok, but it’s “permanent”. If I have 5.1 audio track, that’ll effectively get converted to stereo by this EQ, right? Is there a way to set different DSP settings depending on the number of channels in the source material?
Is there a plugin toolkit that I could use to write an upmix plugin?
If you use the back left and back right channels, you should be able to play 5.1 content as long as the rest of the channel mappings are correct.
Roon has support for developing plugins using our API. However, I’m unsure about wether you would be able to write a plugin that would do what you are asking using it. I have passed along your recommendation for dynamically applied DSP to the development team, I believe we have an outstanding feature request tracked internally for this.
Here is a link to our GitHub repository for the Roon plugin API.
