Hi Johnny,

Welcome to the forums smile

I use Reaper all the time. As Dan says, simply take your BIAB tracks to Reaper, mix them there (which is real easy - probably about 5 mins work) and then record the tracks you want in Reaper while the BIAB tracks are playing.

There is no reason to try and do everything at once. You'll get much better results by creating all tracks and then mixing them as a second step.

My songs at the site below were all created by BIAB, had those tracks transferred to Reaper and my vocals added and mixed in Reaper.

https://vimeo.com/user8682059/videos

Hope this helps.
Noel

MY SONGS...
Audiophile BIAB 2025