Hi Lew,
I was basing my comments on the fact cartridges are not perfectly manufactured, and the more expensive ones are by no means immune to this. They very frequently have cantilevers that are misaligned to some degree (not perpendicular to the two mounting screws holes).
So, you’re frequently twisting the cartridge in the headshell to achieve an alignment with any geometry you choose.
One’s altered alignment could have the effect of "fixing" this square-ness relative to some reference point on the headshell or alternatively making it worse.
Ultimately however, I think this goes to the greater point - that one’s preference for a distortion profile of a particular alignment will be more noticeable to the listener than any potential stray resonances resulting from going off the reservation by choosing an alternate alignment.
I just don’t know how one could separate all of the variables to test the stray resonance hypothesis, so in the end, it becomes a try it and see (different alignments) sort of thing.
I’ve been wrong before, and by no means am stating gospel here, but regarding your hypothesis, one could argue that a slight additional skewing of a cartridge (we’re talking a fraction of a degree) could break up standing waves.
I just ran through the Ellison spreadsheet (I only have Baerwaald and Loefgren sheets set up - not Stephenson). I hate to call anything trivial, but in this example, we're looking at an offset angle difference of 0.0402 degree difference between the two alignments.
I worked off the assumption that anyone doing this has a fixed mount armboard - that they cannot change the pivot to spindle distance, so this will be held constant. Here's how the numbers play out for a tonearm with a nominal 250mm effective length:
Baerwaald:
Pivot-spindle: 233.0331 (held constant)
Effective length: 249.5657
Overhang: 16.5326
Offset angle: 21.9891
Loefgren:
Pivot-spindle: 233.0331 (held constant)
Effective length: 250.0000
Overhang: 16.9669
Offset angle: 21.9489
Cheers,
Thom @ Galibier Design