χαβουζα + αντιχαβουζα = 0

At your risk. This refers to adding 2 similar mics, one deliberately out of phase. Bass, mid heaviness is canceled. So is part of bad acoustics, noise. See previous posts. (For example 2 Shure SM59 microphones). What is best, this technique or using a Pleiades (175mH:175mH) bass correcting inline transformer followed by a Pleiades (130ohm,29Mh) mid correctking inline filter? Mics were used at 24in, about 30 degrees above head. Difficult to answer at this stage. Both tecniques sounded good and promising. The noise cancelling mic tecnique gave perhaps a more pro result as early reflections seem to be diminised. The mic filters gave nice timbre devoid of bass, mid heaviness ie a nice bright detailed sound too. A usefull experiment to decide would be perhaps better, ie studio acoustics or outdoors.