Point At Stacks -verses- Piece Of Shit? I'd go PAS every time.
Maybe POS = Point Outside Stacks? If so..
I think of PAS/POS is a configuration based on simplicity, practicality and ease of setup. All of which are valuable things, and oftentimes the most important things. I don’t think I need to say anything about the simplicity and ease of setup.
In terms of practicality, it points the most well behaved and most sensitive region of the microphone's pickup pattern more or less directly at the primary sound sources, and the least well behaved and least sensitive regions away from them and towards the non-direct room sound (and much of the direct crowd noise). For those reasons it makes pretty good sense at the individual microphone level for the situations in which most around here find themselves recording. In tech-speak it maximizes the direct to reverberant pickup ratio for that particular recoring position. In taper-speak a higher ratio there is more SBD-like, a lower one more back of room AUD-like.
However, if PAS happens to provide a recording with good stereo aspects, that’s entirely by chance determined by the geometry of the particular situation and the width of the mic-bar, but certainly not by design. In fact, most of the time PAS will not be an optimal setup for the stereo qualities of a recording, even if each mic individually is positioned more or less optimally in regards to those other things. But stereo quality is a high-level nicety, which needs to be built upon a strong foundation of that other stuff before it can shine. It’s more important to get the other stuff right first.
The primary problem is that for any near-spaced stereo recording configuration, the optimal angle between microphones is directly tied to the spacing between the microphones. Change one and you need to change the other as well. PAS only specifies the angle between microphones and doesn’t say anything about their spacing. Notice that most other common near-spaced configurations specify both the angle between the microphones and a specific spacing between them (ORTF, DIN, DINa, NOS, etc)
PAS can work based on same theoretical basis of those other configurations for making recordings with good stereo qualities if the correct mic spacing is determined once you know the mic angle needed to point at (or outside of) the stacks. Usually the mics need to be spaced much wider apart than they are.
I posted a quick reference chart a few years ago with suggested spacings for various PAS angles using cardioid pattern microphones. It’s based on the Stereo Zoom tables which describe a way of trading mic angle against mic spacing for more consistent and predictable stereo qualities. It may be useful to some and I’ll link it here if I can find it. The problem with using it is no longer simple and easy to setup- you point the mics at the stacks, then you need to figure out what that angle is, consult the little table, and have a simple enough way of adjusting the mic spacing to suit. Those two things present the same if not more hassle than using the standard configurations. However, in combination with supercardioids it does let you maximize the direct to reverberant ratio from that particular recording position while also getting good stereo qualities.. and that's the real value of it I think.
The practical take away is this- If you setup PAS, you’ll probably have a rather minimal angle between microphones and will need more spacing between them for good stereo. As a point of reference, DIN is 90 degrees and 20cm apart (about 8”), if PAS puts the mics at less of an angle than that, you’ll need more spacing between them (a lot more as the angle decreases significantly). If you are constrained by the length of your mic bar, then pointing outside of the stacks is a good idea because it makes the angle slightly wider, which requires less spacing, but still keeps the mics on-axis for all practical purposes, which maximizes direct/reverberant pickup ratio from that position.
Topic: PAS/POoS (Read 5255 times)