Murray, I think that acoustically the effect would be from the increased surface area of the kerfing itself. The only thing I can think of would be say, lining your sturdio with cardboard versus lining it with cardboard egg cartons. I know that may not be the best example, but I think you can see the principle involved.

As to whether that would affect the sound in any significant way.........I wouldn't put much in it one way or the other. You're dealing with a handmade guitar and if it were possible to build two exactly alike except for the kerfing (impossible), then you could hear for yourself. I kinda' doubt that even if it were possible you could hear any real difference.....maybe, maybe not.

A hard surface does reflect sound waves better thn a soft one, but you do have a bit of a tradeoff with the extra finish. If you didn't coat the soundboard and only the back and sides, then perhaps you might have a positive tradeoff......again, hard to tell.

I think the obvious great ideas are the tunable bridge saddle that he has made work which would benefit the overall sound of any Twelve and the solidly affixed bridge which brings max resonance to and through the top. That stuff is great! Note too, that this Twelve has a 12 fret neck and the double adjusting neck would be almost a necessity in terms of relief and "no-buzz" fretting with a capo. That's all some simply great stuff and well done to boot......hard to beat a great idea that's well executed.

I would say that too that one reason this Twelve reportedly performs so well "out-of-the-box" is because of the Redwood soundboard. Redwood ages and matures a bit, but it's very wide open from the gitgo and you will get very little difference in sound over the years. Spruce does need to vibrate and age to get the best performance so I doubt that an Engleman top would sound quite as good and definitely not as "booming" when new. If you pick up a spruce top 12 and it sounds monstrous when new, it will be a killer in a few years. Redwood will sound about the same new as it does in 20 years, and it's life expectancy is a bit shorter than spruce from a sound standpoint. It is also a bit...and I emphasize a BIT.....more prone to cracking. Again the bridge and neck innovations will help to negate that problem.

Spaw