Hey Moot...

BIAB tracks are centered and transferred to the DAW (Reaper, Sonar Producer) as stereo tracks. Vocals are recorded mono, as well as Brad's acoustic guitar, and Chris' steel. Here is our general panning setup:

Bass-Left 8-10,
Drums Right 8-10,
Acoustic fingerpicking guitar Right 50,
Other rhythm (if any) Left 50,
Steel guitar Right 75,
Fiddle Left 75,
Lead vocal- 0 (zero pan),
Harmony vocals Left 90, and Right 90.

Adjust to taste. Master mix is rendered from the DAW in stereo at 192kps for MP3, and 44khz 16bit for WAV.

Obviously there are a million ways to mix a song. I like to set my panorama as though I were viewing/hearing the band onstage. Wide panning of backup vocals creates a nice fat vocal sound. Lead instruments (steel, fiddle) are kept well away from the lead vocal which always has it's own sonic space. No reverb for the bass, but some compression to keep the bass tight and focused. After topping and tailing, the final mix is slightly compressed and about 3db of highs added back in at 7khz and above.

Thanks for listening,
Bob

BIAB 2018 ULTRA
https://soundcloud.com/bob-buford
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