Hey, I hope it helps!
A few comments on the previous revised table which I removed, and the new one-
The only thing the older table included which the new one does not was a choice between four different Stereo Recording Angles (SRA's) for each PAS angle. The four choices provided were
SRA = PAS angle -10°, SRA = PAS angle , SRA = PAS angle +10°, and
SRA = PAS angle +20°. Solving for each of these was acknowledgement of what I see as the primary subjective variable of the
Improved PAS method and of the Stereo Zoom itself (as mentioned by Michael Williams in the paper)-
What is the most appropriate SRA?. I originally included the four choices so that after using
Improved PAS a number of times and trying those different variations, folks could home in on their prefered PAS SRA. My thinking being that after a while we may be able to come to a consensus on which is most prefered. But taping isn't some rigorous methodical scientific study and I realized it's just not realistic to expect much reporting back of which SRA option folks used along with how they felt about the imaging derived from it, much less reach any general consensus.
So for this table I just solved for
SRA = PAS angle +10° for all entries (approximately, with a tolerance of ~ +/- 1°). This is what Williams suggests as probably most appropriate for orchestra sources, is what I suspect is close to optimal for PA taper recording, is sort of the intent behind pointing-just-outside-of-stacks (although generally not what that really does, which is partly the reason for doing all this), and was the suggested starting point in the old table represented by the highlighted row entries.
A few implications of SRA = PAS angle +10° are-
The microphone spacing for any given PAS angle are slightly
narrower than they would be for SRA = PAS angle.
Improved PAS tends to suggest spacings much wider than tapers generally use for traditional PAS, so a slight reduction in suggested setup spacing is probably a good thing in a practical sense. It's difficult enough setting up wider spacings to begin with, and I suspect the spacings
Improved PAS suggests may seem overly wide to many tapers simply because they differ from the traditional norm. In defense of the wider spacings, I'll stay that most common near-spaced setups (ORTF, DIN, DINa, NOS) etc fall within a range close to what the SZ suggests, and by extension what the Improved PAS method suggests. What is difficult for some tapers to accept is the basic implication that narrower angles between microphones require wider microphone spacings to compensate, or rather the extent to which that relationship pushes the configuration wider rapidly as the angle grows smaller.
Another interesting implication can be seen by looking at the fig-8 column. Note that "Standard Blumlein" (fig-8's @ 90° / 0 cm) isn't represented there. Instead, the coincident fig-8 arrangement occurs at PAS angle = 80° (and this tends to correlate with my own experience running Blumlein from an audience perspective). Narrower PAS angles between microphones begin to push the fig-8 microphones further apart, but less so than any other pattern. Since many tapers are constrained to using relatively narrow mic bars, either by the equipment they have on hand or by setup constraints, it may be advantageous to consider using figure-8s in
Improved PAS. Not only do fig-8's tend to sound "natural" (somewhat in a similar way to omnis, not falling into what I sometimes call the "cardioid compromise"), they include a "built-in low-cut" as a result of their bi-directionality which will be appropriate for many indoor AUD situations. Break out your old LD's which have a switchable 8 position and give it a try.
Back to the SRA = PAS angle +10° thing- Anyone using this table and wishing to experiment further and tweak the method, can do the following (quoting myself from one of the earlier explanatory posts in the thread)-
Tweak it to your liking if you want- Play it back and listen. If you prefer a more narrow-image presentation with the on-stage and PA sound more tightly grouped in the middle between the speakers, use a slightly narrower microphone spacing next time (which corresponds to a wider SRA squeezing more between the speakers on playback). If you’d prefer a wider-image presentation, use a wider microphone spacing the next time (narrower SRA stretching things out to the width between speakers). Once you determine your personal preference you can use this table as a guide to get close then bump the spacing one way or the other as you like.
^
If anyone reading this does that a few times and ends up finding a consistent preference for modifying the suggested spacing in a particular direction, please let me know.