Problems downmixing Discrete Quad FLAC albums to 2.0

Core Machine (Operating system/System info/Roon build number)

MacOS Catalina 10.15.4 /
Macbook Pro mid-2012 Retina w/ 2.7GHz i7, 16GB RAM, 768GB SSD
Roon Server (local) 1.7 stable build 555

Network Details (Including networking gear model/manufacturer and if on WiFi/Ethernet)

Ubiquiti Unifi Networking Gear / ReadyNAS Library share

Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)

Benchmark DAC1 HDR over USB

Description Of Issue
I’m new to Roon, and overall I’m loving the product so far… but…
When Roon downmixes discrete Quad FLACs to 2.0, it appears that the rear channels do not render at all. I created a standard channel mapping (FL, FR, BL, BR) Quad FLAC from The Flaming Lips’ Zaireeka 4CD album as a test - each CD contains one quarter of the performance, and they are meant to be each played on a different stereo at the same time. It makes a useful test file because the beginning of each track contains an identification of the CD number for synchronization; when properly synched together, you will hear: “This is CD number one”… “number two”… “number three”… “and number four.” On a two channel system, you should hear the voice moving L… R… L… R as it plays back each channel, but playback in Roon results in only the first two channels being heard, and there also appears to be a phase error between FL and FR, since the center image is missing. The same thing also happens with a 4-channel FLAC of Dark Side of The Moon (1973 Quad Mix). I noticed that the forums have a few articles regarding channel mapping issues, so maybe this is part of the same problem?

Hi @seanlake,

Can you please share a screenshot of your Signal Path when these tracks are playing and a screenshot of your Device Setup for the zone? Device Setup can be accessed in Roon Settings -> Audio -> Cogwheel next to zone -> Device Setup. Please include both the regular and advanced section of Device Setup.

Hi @seanlake,

Thanks for those screenshots. I’d like to get your report over to the technical team for closer review, but can I please ask that you send me a copy of the media which you are using to reproduce this issue?

You can upload the sample media to Dropbox / Google Drive / and provide a link via message (click my name -> message).

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