In the past I used a non official plugin called audiopip. It is very obsolete and it has no longer developed. But you can try.
Otherwise you can try the Big PiP mode in OBH that is even simpler compared to how AudioPiP works (it took me a bit to make it work and I succeeded when I did differently from what I read in some forums).
Consider, in case you've got a Solo4K, that Big PiP mode under OBH does not work for Solo4K, but it does for other VU+ models.
In the OBH's Big PiP mode, you have the PiP in full screen, so you can zap to another channel and you'll hear the other channel