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I'm working on # 7, which is a yellow siris Weiss style.
Can anybody advise me on what notes the tap should be on the braced top,
and the braced back, not attached to the sides?
I've read here at least a semi tone away,
but it could be as much as a fifth? Huh? So it really doesn't matter?
I know (think?) it will change when attached to the sides,
and think that would be more important time to tune, no?
Also, I'm confused because I'm reading different things here about removing brace to raise/lower the note.
I think removing material would lower it.
What I'm doing now is tap and write down what note I'm hearing at all the stages.
Can somebody please help?
I'm driving myself crazy with this.
Thanks!
Alan

Hi Alan,
I've read keeping the top and back anywhere from 1 1/2 to 1/2 of a tone apart is acceptable, and to have it tuned between standard pitches.
Generally removing weight will raise the pitch, and lessening stiffness will lower it. When you shave a brace you remove weight which raises the pitch, but you usually also lessen the stiffness which lowers it. Scalloping the braces lowers the stiffness a great deal without removing too much of the mass. Making your braces tall and thin keeps them stiff without adding much weight.
After you assemble the box, you get to decide how to make your bridge. By adjusting the size and "wings" you can make it light and stiff, or heavy and flexible to further adjust your tap tones.

Wow!
Thank you Clay!
You've simplified it for me.
Alan

I finally tried something I've been thinking about doing for a while.
I plugged a microphone, similar to a Shure model 57,
into my Boss TU2 tuner, and bonked the tops and backs of some builds I'm doing,
and it works!

Okay, I need more help with this.
I've shaped and sanded my braces on the top and back, to what I think is right looking, and flex wise.
When I bonk them, the tuner says the top note is smack dab between a C # and a D.
The back is reading between a G and a G#.
The top C#+, is the lower note.
By the way, this siris has an amazing bong to it.

How thick is that back? I doubt you could drop it that far just by shaving braces. Might need to peel them off, thin it some more, and re-brace if you want to get the tap closer to the top. But that amazing bong might turn to a bunk... at least until you get it glued to the rims. Then maybe the bong would have become a bink and the bunk would bong once again.

I've only completed one guitar though. But my construction order is sides to top with dentellones, back to body with spool clamps. And it turned out that by dry fitting the back with spool clamps, I could hold it up by the soundhole and tap to get a reading on the top-back echo. In my case, the back was lower frequency. So I shaved the top some, which made it sound better anyways, until the echo really got loud. Then I glued the back on... and the echo went away almost entirely Then I installed binding, and it came back better than ever
Later on, I remembered that I had a small gap along the lower bout between one of the sides and the soundboard, from not holding it down well enough when gluing dentellones. So it had a sort of sound port. I suspect the bindings closing that up is what fixed the echo, although I'm not sure it wasn't some other effect of the bindings changing the weight or stiffness of the rim. But now I have to wonder, did I just get lucky? The gap was there when I got the good echo with spool clamps on...

I'm going to be closing up another one here in the next couple days, so we shall see what happens this time. Although this one will have no binding, so it will only be a yes/no on whether echo with dry fit leads to echo after gluing.

Thanks Dennis for the reply.
The back is at.095",
and this stuff is REALLY supple.
At that thickness I could almost bend the thing into a closed cylinder,
so, I don't think it needs more thinning.
I think I'll take it to a luthier I know of here.
He's pretty good, and might give me some advise.

Indeed, sounds like some in-person advice would be most helpful. That seems quite thin to have that big of a difference, even on denser woods. Does it actually sound that much higher, or is it only the computer that says so?