Maybe I misunderstood some of the comments, but since you asked...
You seem to present addressing
feedback only via EQ and don't seem to even mention mic positioning, the relationships of mics and speakers and their patterns, the importance of the distance from mouth or source to the mic on
gain before
feedback and all the other possibilities that generally should be considered before resorting to equalization. There are times 'under fire' that
level and equalization may be the only tool available at that moment, however using EQ o inprove
gain before
feedback should be more a last ditch effort than the first step. People's first response to
feedback being applying more equalization is one of the most common bad practices I encounter and this seems to encourage that.
I disagree with using the
house EQ to
address feedback from mics. Each
microphone can have a different relationship to the speakers, room, user,
etc. so you cannot assume that what affects one
microphone will affect others, much less in the same way, yet any adjustment to the
house EQ will affect every
microphone the same along with every other source. Use the
house EQ where you want to affect everything, but for
feedback use the
channel EQ and
address the offending mics individually if at all possible (and after first trying to
address it in other ways).
You
address using high pass filters and rolling off the low end, however you don't seem to identify that this recommendation is specifically for vocals and not recommended for every mic or input. Also note that studies have found that the fundamental frequency of male vocals is typically around 120-125Hz and can be lower so a 160-180Hz high pass, which is probably already being down 3dB at that frequency, may filter out most of the male vocal fundamentals and may be part of the reason that most
mixer manufacturers use 60-80Hz for the high pass filters.
The section on area micing seems to contain some errors. For one, most
PZM mics are not omni, in fact they by definition can't be omni, only hemispherical, and many are directional, for example the venerable
Crown PCC-160 is
cardioid (or half-cardioid due to the boundary). Speaking of which, for a
PZM to function as a
PZM it requires a boundary of a size appropriate for the frequencies involved, if you mount a
PZM to a small vertical surface and have it near the floor you can get limited benefits of a
PZM and potential negatives such as floor
bounce. A simple one but it is the 3:1 rule, not 2:1. Finally, it is often perfectly acceptable and even desirable to include hanging or area mics in the mix, in fact they are often a better approach than some of the options recommended. This is especially true if the 'main mix' is also used to derive signals for balcony fills,
ALS feeds, remote audio sends, backstage monitoring, archival recording,
etc.
Sorry if this seems overly critical but it is intended to possibly improve the information provided and generate some discussion.
