If it's wide open like that you can likely use a quieter fan. Pretty big deck for a pair of 572Bs. BIG meters. Unfortunately the builder put the plate tune and load and bandswitch all at the same level, using the same kind of knob. That leads to more cases of "oops, I turned the bandswitch while tuning up!" problems than almost anything else. Always good to put the bandswitch at a different level and use a different kind of knob to help prevent such mistakes.