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So for a jumbo guitar top, what would be the minimum grain lines per inch I would go for in the middle? or it doesn't really matter as long as it's braced heavier in that area?

I just received my new top from stewmac. I am using Engelmann spruce this time (I like the whiter color). The problem is one edge has really wide grain spacing (about 10 grain lines per inch) and the other end has much denser grain lines per inch (like more than 30) however the problem is there is some very ugly pitch pocket right dab in the middle (about 1" in) that goes all the way through the board. So that means if I join the board at the denser edge, I get very stiff centerline but with ugly pitch pocket right there (I tried moving it into the soundhole and the bridge but it doesn't work) or else I can join at the other end that would avoid the pitch pocket completely (would be cut off) but the centerline will have some rather wide grain spacing. Any advise here? The top is .135 as arrived from Stewmac and I won't be sending it through any thicknessing device anytime soon!

I am thinking I could cut off 1" but I don't want to risk making this top too small, especially for a questionable sonic difference.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Trace out half the body profile outside of the pitch pockets running the center line close to the pitch pockets. You might be able to just cut that portion of the top away and join and the closer grain lines.

Apart from that, generally I would say it doesn't matter, but you what you have to know is how stiff the top is (that usually only comes from experience of flexing hundreds of tops) before you start working it. It can be left thick enough to be stiff enough either grain spacing you choose, but that's next to impossible to describe.

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Sometimes you can get a flaw to be inside the soundhole, or under the end of the fingerboard, where it won't matter. I made a classical last year that had a pitch pocket, and the best I could do was put it in the rosette area. The inlay covered it, and with a doubler on the inside you'd need to do a CAT scan to find it.

I'm told there is a small statistical correlation between stiffness to density ratio and grain count. Generally speaking, open grain tends to be a little less stiff, and less dense, and the stiffness rises faster than the density as the grain gets tighter for a while. The max seems to come at about 24 lines/inch, and by 32 lines you've gained more weight than stiffness. But the correlation is small, and you really have to go by what the top in your hands does.

Usually the tighter grain is toward the outside of the tree. The way they cut tops you are more likely to end up with dead-on quartered wood near the outside of the tree, with it runnig more to skew (45 degree grain angle) as you go toward the center. That's one reason we tend to joint outside-to-outside: you've got the best quartered, most stable wood with the highest cross grain stiffness in the center of the top. but, again, that's an average case; you have to figutre out what you're looking at and decide accordingly.

One counter-indication is runnout. Often when a tree grows with a twist the twist increases as the tree gets bigger. A top cut from that sort of tree will have more runnout toward the outside, and if you join it bark-to-bark there will be a big change in runnout across the joint line. This is not only unsightly, due to the change in reflectance, it's structurally not good. The bridge will tend to peel up easily from one side, and pull grain out of the top on the other; not a good combination. In a case like that it's better to join heart-to-heart, where the runnout can be much less. This sort of top can be tricky to get right in terms of tap tones or Chladni patterns, and you might find that asymmetric bracing heights are needed to get the stiffness to be the same from one side to the other. I had a guitar with a top like that at last year's Montreal show, and one person said it was the best sounding one there. Nobody said anything about the wide grain in the center.

I can cut off the portion with the pitch pocket. I tried getting the pitch pocket inside the soundhole as well as under the fretboard but it just won't work. The pitch pocket is too elongated for this to work. I could cut off one inch but that means I am left with about 1/8" of scrap once the pattern is traced on. This seems a little risky but who knows. I was wondering maybe I should go ahead and cut off the pitch pocket portion then if there are missing pieces I could cut off a waste portion (where the grain is similar) and graft it right where the missing piece is. Hope this works...

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Very often I join tops with the wide grain in the center. I mostly use engalmann, and there are times it just looks better done that way. Many Martin guitars also were done that way. I try to keep my tops a little thicker under the bridge, and having wider grained (potentially - lighter, less dense) wood in that area doesn't seem to hurt.
I wouldn't have a second thought about it, if the wood is good.