The key idea is to combine tracks recorded with
1) the Sennheiser Ambeo Smart Headset (binaural)
AND
2) the Rode NT4 pointed to the source - the stage, but maybe also the PAs in really horrible boomy scenarios. Maybe as an alternative to the NT4 I would like to use two Bayer M201TG hypercardiods in X/Y configuration for more flexibility
MORE DETAIL ON THE SETUP(s) I would like to test, three versions with different SIDEs S
SETUP 1 - SIDE S is given by Sennheiser Ambeo Smart Set
(simple and stealth, I expect less phase issues but less stereo separation)
SETUP 2 - SIDE S is given by two DPA 4060 at the ends of the longest possible telescopic arm
(more cumbersome, it needs two recorders (or something like a Zoom F6 that I do not own) and a longer arm. It could give more stereo separation but maybe it will show comb effect)
SETUP 3 - SIDE S (extended) is given by two hypercardiods (Beyerdynamic M 201 TG) at the ends of the longest possible telescopic arm
(even more bulky, it needs two recorders and heavier mics and arm, but it can be good to catch a PA in desperate reverberant cases)
The FRONT MIC(s) M would be in all three cases
One hypercardioid (Beyerdynamic M 201 TG) or a shotgun (*) pointed to the source
OR
(“extended” M) Two cardioids X/Y (Rode NT4) or two hypercardioids X/Y (Beyerdynamic M 201 TG) pointed to the source
If using two microphones (keeping things simple) and wanting to improve your odds of making a good recording in a difficult acoustic, I suggest first determining the location of the best recording position in the venue and setting up there if possible. If not possible, choose the best location that is practical. Then arrange your Beyerdynamic microphones in a stereo configuration determined by the width of the PA and stage as viewed from that position and the suggested microphone angle and spacing combination indicated on the
improved PAS table linked in my signature. You might want to run the Sennheiser Ambeo Headset separately to provide a point of comparison.
If recording more than two channels with the intent of combining them later, I strongly suggest recording all channels to the same recorder. This requires a recorder capable of recording more than two channels of course.
It can also be done using separate recorders that are digitally clock-linked so as to remain synchronized, but that's probably not in the cards. Technically if can also be done using two entirely unconnected recorders but honestly that's a real hassle and likely to be more trouble than its worth. Recording to two separate recorders that
are clock-linked requires more effort and complication before, during, and afterward. You'll need to wire to recorders together, make sure they are clock linked and recording together, and afterward get the starting point of the files perfectly synchronized. To do the same using two entirely separate un-linked recorders requires somewhat less complication before and during recording, but is a lot more complicated afterward. You'd then need to not only synchronize the start of the files, but also alter them so they will play at exactly the same speed and remain synchronized throughout until the end. Honestly, its probably not worth it in comparison to the cost of a four or six channel recorder these days, where all channels will be perfectly synchronized with each other without any effort.
Alright, lets assume you are using your Ambio binaural pair as the foundation of the recording and want to add a single Beyer hypercardioid to that to increase clarity. First, you'll want to keep the geometric relationship between the binaural mics and the hypercardioid the same throughout the entire recording. Don't allow the microphones to move relative to each other. If they do you are likely to hear phasing once combined. Binaural on your head and the hypercard in a hat maybe? Non-moving dummy head fro the binaurals? Either way, point the hypercard directly at the loudest, clearest source, likely the closer PA speaker, and orient the binaural pair so that the the sound as heard from that position is Left/Right balanced in an auditory sense, regardless of how things appear to the eye. Don't face everything stage-center based on what you see, face toward the apparent "acoustic-center" even if that means turning more toward the left or right. This applies to any microphone configuration.
If you use the Rode X/Y mic in place of the single Beyer hypercard, or both Beyers in X/Y, do the same, except recording 4 channels instead of 3. If you use the DPA omnis instead of the Senn binaural headset (on your head or spaced farther apart somehow) approach it the same way. I think you get the picture.
Once home, transfer all the files to the computer and play around. This is the fun and educational part. You can try whatever you want, whatever you think of. Listen to each part alone. Get each part sounding as good as it can in isolation. Play with various level combinations. Try everything full range, try implementing crossovers if you want, try different equalization between each parts (which in effect acts as sort of a less domineering cross-over), try equalizing the resulting combination and how that might affect your level combinations or EQ of the parts. And so on and so forth. It's your baby to raise as you see fit. Go back regularly and compare with your straight 2-channel stereo pair, or someone else's recording of the same event. Question what you are hearing and what you decide sounds best. Take listening breaks and return with fresh ears. Listen elsewhere. Ask what a friend thinks. We'll be here with advice if you want.