Topic: Can someone explain to me the logic of X/Y stack taping?

[acidjack]

I understand that stack taping in open-taping situations is almost always considered the move of last resort to begin with (bad crowd, bad venue, etc.), but I've always wondered why the conventional wisdom seems to be that a stack tape should be made X/Y. 

In particular, if you've already decided to just aim your mics at one PA stack, aren't you by definition deciding that you really just want the direct sound from that stack, in which case, you'd be better off just pointing straight at them?  I suppose the wider soundfield would give you more reflections, etc., giving you a more "lively" recording - but again, if you're stack taping, aren't you almost always trying to AVOID those things? 

And finally - I assume this method should be avoided if, say, there is a wall or something else to one side of the mics, as that would give you loads of reflection off one side and none off the other.  I've seen a taper here in NY run mics down from a side of the balcony with them XY pointing at the stacks - meaning one mic is aimed almost directly at a wall with very little clearance.  Does that make any sense?

[vanark]

 I've run A-B pointed directly at the stack in those situations.  Doing anything else didn't make sense to me.

[ideal77dlr]

I'd say go A-B as well just on common sense.

[F.O.Bean]

because no matter WHAT you are recording, whether it be a stack tape or a section/fob tape, you can still trick your ears into hearing a somewhat 3d sound, versus the 2d sound of AB, at least that's always the way I've looked at it.

[Brian Skalinder]

IME, when stack taping one still must decide on mic configuration -- whether XY, or AB, or something else, it's about finding the right balance between sound source, room, crowd, etc.  Even when stack taping, the mics still pick up the crowd and room to a significant degree.  Running XY with an appropriate included angle, or AB with an appropriate spacing, emphasizes the stereo nature of the crowd and room to the degree it's possible given one's environment, while running near a stack also helps reduce the negative aspects of the crowd and room.  So while "stack" taping does in some ways seek to minimize problematic rooms and crowds, it's essentially impossible to remove them from the equation outright -- and even if we could do so, I personally wouldn't find it desirable.  I think XY or AB (or some other config) mostly comes down to whether one prefers intensity-difference stereo or time-difference stereo (or some combination of the two).  Perhaps those running XY prefer intensity-difference stereo when stack taping?

FWIW, my general preference for recording in poor sounding rooms (whether stack taping or not) is to run wider spacing with a narrower included angle to maximize sound source signal to reverberant sound, while still maintaining as good a stereo image as possible from time-arrival differences.