I'm assuming they are not a 'pair' as such, just two standalone speakers?
You could group the pros in the wiim app and set one to output the left channel and the other the right.
Minis might also do, but depends on whether you specifically want pros for their extra functionality etc.
See screenshot - note the L and R at the end of the volume sliders. Press those to cycle theough the options (L, R, LR).
A group is limited to 48khz sample rate I believe, if that matters to you.
Note also that a group introduces a delay from the original source - not an issue for audio only, but if your source was, say, optical in from a tv then you'd have lip sync issues.
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