What's the point of "Downmix audio to:" in advanced preferences?

[Former user]

I'm not clear about this setting option, since when I open a new file I have the same list of choices in the action column. I tend to always go for passthru but what does that do if I have "downmix audio to" in the advanced preferences set to mono for example? Just trying to figure out the logic.

[Damiano Galassi]

It's the default option. And it's useful when you use the queue.