This is me quoting Doug Ramsey quoting David Berger.
This is acoustic music. Keep amplification to an absolute minimum; in the best halls, almost no amplification should be necessary. Everyone needs to develop a big sound. It is the conductor’s job to balance the band.
The bass should not be as loud as a trumpet. That is unnatural and leads to over-amplification, bad tone and limited dynamics. Stay away from monitors. They provide a false sense of balance.