Had a similiar but not identical situation a while back. Trouble with these mini festivals is there run by semi-pros who aren't good under pressure...How many bands?...Fast turnaround? I played a P bass with dead flats into my ole Ampeg rig...so, lovely gnarly mid focused punchy tone in stage. However the play back recorded live in the ground with pro mics, I sounded like an Alembic with fresh rounds, clangy and tinny as heck .... and, it was a substantial setup...kinda like the smaller Glasto size stage and big pa. In other words the sound guy under pressure had not a clue.