How Roon handles 5.1 with 2.0 source material

Hello everyone. I’m loving the latest update (1.3 Build 196). I have a question regarding how Roon is handling 2.0 source material.

My setup is simple: Roon -> JRiver WDM Driver [WASAPI] -> HDMI -> Yamaha Receiver [5.1 setup].

The latest update did fix my multi-channel issues by letting me choose 5.1 in the audio setup, but it’s not working how I expected. It may be by design.

All music is being played at 5.1 (whether it’s 5.1 source or 2.0 source). It’s working well, but what I was hoping for is Roon to play 2.0 source material as 2.0 and 5.1 source material as 5.1. Ideally 7.1 source material (I don’t have any to test) would be down-mixed to 5.1. I wasn’t expecting the 2.0 source material to be up-mixed to 5.1.

Is this by design?

If you have Multichannel Mixing Strategy set to Channel Mapping Only under the Audio Device’s Playback, then Roon simply routes audio between any channel that the source material and the device have in common. Which means that when you play 2 channel material only the standard Lft/Rght channels are going, etc etc

But, you are routing it through JRiver which has its own settings and their may be settings on the Receiver to upmix it to 5.1

Roon isn’t actually up-mixing (we haven’t built any up-mixing support yet).

What Roon is doing is mapping the 2ch stream onto a 5.1ch layout–so it’s sending the left and right channels from the source into the left and right channels of the 5.1 and leaving the other four channels playing silence.

We could probably get away with making a special case for stereo output that does what you expect since pretty much everything will accept 2 channels and do the right thing with them, but we couldn’t safely generalize that idea to other layouts. It’s very common for devices to take 2, 6, 8 channels but not all are happy with other counts, and others that might accept them but do the wrong thing.

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Thanks for the replies. I’ll check my JRiver settings.

Is this something you’re considering? Are there are any good options apart from proprietary technologies like Harman’s Logic 7?

We’re not actively working on it, but it’s not totally off the table if there’s sufficient demand for it.

My personal opinion is that upmixing + room correction are better off combined–it’s not really just upmixing, it’s about mapping an n-channel stream to m speakers in a way that produces the desired sonic image in a room. In order to do that optimally, you must take into account speaker behavior and position (a la Atmos).

That is probably out of scope for us in terms of DSP intellectual property that we might create. It would be better for us to license something or partner with a mature player in that space for a goal that large.

A simpler remixing engine (for instance, something like JRiver’s JRSS) is feasible. Despite that stuff being very straightforward, a lot of people seem to enjoy it. I think if we were to do something ourselves, it would be along these lines.

People with more serious needs and bigger budgets will always have options in the hardware world–AVR’s, and swiss-army-knife surround processors from companies like Trinnov. These have the added benefit of working for more than just Roon content.

Thanks. I, for one, would be interested, particularly if you found a partner with a mature solution.