Todd, I'm sorry if I've come across as more strident or vociferous than usual on this thread. Your mention of the rabbet cut for a purfling channel is interesting. If that's something that does affect the sound, then other purfling such as herringbone trim should have a similar affect.
I guess what sparked my (mild but undeniable) indignation over the whole idea of abalone purfling "improving" the sound of a guitar is that it's a fairly blatant, self-serving sort of thing, especially if the guitar manufacturer can convince potential buyers that thirty dollars worth of abalone is worth paying thousands of dollars extra for a guitar.
In the olden days (as in a few years ago,) there WAS more hand labor involved, cutting out all those little pieces and gluing them into place. Now, though, it's literally just a few seconds work gluing pre-sized laminated abalone strips into their channels.
I think John Greven's comments earlier in the thread are valid - maybe I'm just as old school in this regard as he is. If the rabbet cut for the purfling channel does have an impact on the sound, that makes far more sense to me than the abalone doing it. So that possibility that you've raised changes my math on this from being 100% implausible to perhaps 5% plausible, 95% wishful thinking.
That said, even if this theory about the purfling channel changing the tone turns out to be 100% correct, we're still - as Mycroft put it - in "how many angels can dance on the head of a pin?" territory.
Any tonal impact from abalone purfling has got to be exceedingly minor, if it exists at all.
But I think we're in agreement there. As another thoughtful contributor early in the thread wrote, everything in an acoustic guitar contributes to the sound somehow. So I've turned down the dial on my Vociferous-O-Meter®, and will respond more gently on the topic in the future.
Just as I do when I read comments about the supposedly miraculous tonal effects of fancy aftermarket bridge pins. Both subjects set the klaxon howling on my BS-Meter®, but that doesn't mean I have to come howling into the thread and land on it tromping around in hobnail boots.....
NOT My Favorite Communication Style
Short version: I remain unconvinced, but I always appreciate your comments and insights, Todd, and thank you for contributing them to this thread. What's more, I'm in 100% agreement with you that opposing viewpoints should definitely be expressed,
especially when they have evidence backing up their assertions.
More power to you, Todd, and all you others who hold a
number of different viewpoints on this subject. The free and civil exchange of information is what this forum is all about.
Wade Hampton Miller