The why and where-
The table is based on data from the excellent
sengpielaudio page which has been linked here at TS many times before. It’s a great tool.
The inspiration to revisit this was
deadheadcorey's recent thread titled- PAS/POoS which got me thinking again about why the PAS configuration makes a lot of sense in difficult recording situations such as rooms with bad sounding ambiences, overloud obnoxious audiences, and recording positions which are further away from the stage and PA than we'd choose, because it helps maximize the direct/reverberant pickup from a given location. In simple terms that means it focuses as much as possible on the sound from the PA and band on stage (the direct sound), and less on the sound arriving from everywhere else (the reverberant, ambient sound).
The most effective way to maximize the direct sound and minimize the reverberant room sound is to move closer to the source. The extreme is stack taping where the majority of the sound arriving in the recording position comes directly from the PA and very little of it is reverberant room sound (at least in proportion to the PA sound). The opposite extreme is the far back of an arena, where the situation is reversed and most of the sound arriving at the recording position is reverberant room sound, swamping the direct sound.
PAS using supercardioids maximizes the proportion of direct sound picked up verses the reverberant sound
as much as possible from a given recording location. It isn’t a substitute for finding the optimal recording location and it certainly can’t make the back of the room sound like the front. It simply makes the best of a mediocre situation. From a good recording position in an excellent sounding room, other configurations may be more appropriate, but using the table won’t make a bad recording. It’s entirely possible to have a direct/reverberant ratio that’s too high. That’s one problem with a stack tape or a straight SBD, it’s mostly direct sound that often doesn’t have enough good reverberant room information and sounds not so 'live' but rather lifeless.
The problem with the typical PAS setup is that it doesn’t indicate how much spacing is appropriate between the two microphones. Most tapers simply use whatever spacing their mic bar provides. At the narrow microphone angles typical of PAS, the spacing between microphones is often not enough to achieve good playback imaging which evenly fills the space between speakers with phantom images (or sounds open and as if ‘you are there again’ over headphones) and provides an appropriately wide and involving audio illusion with the audience applause wrapping around the listener.
PAS is a dedicated concert tapers microphone configuration and this table quantifies it to make it a more valuable tool with improved stereo imaging.
Here's a link to the original thread discussing the first go-round at this, which partly works through the process of developing the table-
!!Stereo Zoom simplified for PAS!!The new version of the table expands on the original by extending it to multiple microphone polar patterns other than cardioid.