Core Machine (Operating system/System info/Roon build number)
CAPSZuma server with i7 processor running RoonServer Build 537 on WS2019 with Audiophile Optimizer
Network Details (Including networking gear model/manufacturer and if on WiFi/Ethernet)
Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)
Multichannel DAC consisting of four Musical Fidelity V90 2-channel DACs networked as a single DAC with the miniDSP UDIO-8 interface connected to the 7.1 analog inputs of a Marantz 8802A pre/pro
Description Of Issue
This is a Roon channel mapping problem for which I have spent many hours troubleshooting with @Omid_Mostachfi over at the Audiolense user forum. We have discovered a solution but it is clearly a bug in Roon for future consideration. In addition to advising @support, this posting is to save others the troubles I’ve been through.
I apologize for the length here, but it may help the Roon engineering team to duplicate the issue for themselves.
Most of my multichannel listening is of 6 channel material, either DSF or FLAC tracks. In my main system, I have two subwoofers. Therefore, I have been working to use Audiolense filters in a Roon to support a 5.2 channel mapping.
Audiolense properly measures all seven separate channels, to wit: front left and right mains, center, left and right surrounds and the two subwoofers. On Marantz pre/pros, there are two subwoofer outputs. However, except for using Audyssey sound correction built into the pre/pro, the two subwoofer outputs run the same. So, the only way to measure and filter each sub separately is to plug one sub into the pre/pro’s labeled subwoofer outputs (either of the two) and plug the other subwoofer into a seventh channel. When Roon plays out through the Audiolense filters so created, there is no sound for the center and surround channels.
Disengaging the convolution filters causes all channels to be properly identified and populated with sonic output.
Audiolense created a filter that, in relevant part, looks like this:
48000 6 8 0
0 0 0 0 0 0
0 0 0 0 0 0 0 0
You can see that channel 0, the left front main, is mapped to the left front inputs and outputs. Same for channel 1, the right front main, and channel 2, the center channel. Yet, as noted above, no sound comes out of the center channel speaker in Roon when the filter is activated.
As a test, we edited the cfg for channel 0 to read:
We expected this would cause the channel ID for the left front input, which we knew was working with the filter enabled, to come out of the center channel.
Imagine then our surprise when not only did the left front channel ID come out of the center channel, but so did the center channel’s own ID! Reverting channel 0 back yielded silence out of the center channel again, so this was repeatable.
@Omid_Mostachfi thought with this unusual result that perhaps Roon could be fooled into properly reading the cfg file. What we did was merely to re-arrange the ordering of the first five channels from 0, 1, 2, 3, 4 — as above — to 0, 1, 3, 2, 4 AND we also placed a blank line between channels 1&3, 3&2 and 2&4. Everything else in the filters created by Audiolense are the same. This caused the filter to be properly recognized by Roon and all seven speakers now play out just fine!
I have Roon configured with event mode on, no swap of rear and surround channels, 7.1 channels and channel mapping only.
I am happy to provide further information on request to assist others or the Roon team with this problem. A shout out again to @Omid_Mostachfi for the assistance on this and to @Mitch_Barnett for his service in teaching me how to use Audiolense. Audiolense convolution filters are a great combo with Roon when they work correctly! Cheers. JCR