I have been having a big problem in a particular venue with a strong magnetic hum field. It makes ribbon microphones completely unusable, and even capacitor microphones with electronically balanced head-amplifiers (i.e. no transformers) deliver enough hum to need attention. The same setup is quite clean elsewhere, and practical positions of the mike and cable make little or no difference, although turning the mike on its side, an unusable position, gets rid of it. The hum by the way is not a buzz from say a lighting fader, but 60 Hz with traces of odd multiples.
Adobe Audition is the only program I have found so far that provides multiple very narrow notch filters which allow me to remove the hum without audible impairment of the music (a small chorus), but frankly I am reluctant to spend $200+ just for the sake of the filters. Other editing programs have various equalization options, but not narrow notches.
Has anyone any suggestions?