Can we assess this top?

[Dave Bagwill]

I have a number of questions concerning the top pictured below - which happens to be a Batson.

1. There is no upper transverse brace since obviously there is no soundhole to protect. That seems like a plus - what do you think?

2. Do you think the X placement would be very important? I think so.

3. I'm considering building a ladder-brace with no hole - I've built one and it is very good sounding - but I did not take advantage of the upper bout as well as I could have, looking at this Batson. I think I could use a lighter brace than an UTB, which would free that upper bout a bit more.

Basically it comes down to this: if we eliminate the soundhole and all the reinforcement it needs, we have an open pallete. How best to use it?

[Daniel P]

I love the idea, and there is a lot to think about.

I am way out my league speculating about no sound hole, an active upper bout and such a narrow x brace angle, but here are a few first thoughts:

That narrow of an x-brace (only possible because there is no sound hole) is going to primarily control the long gran stiffness, and have less impact on the cross grain stiffness. Inherently going to make the long grain very stiff the way it is braced. Will that impede the monopole movement?

Without an upper transverse brace, I would want to add a heel/neck block extension to support the fingerboard interface and help prevent block rotation (Im not convinced the elimination of a a sound hole completely negates the need for proper support in the upper bout.

I don't have an answer here, but how will you both account for and control an active upper bout to ensure you don't get phase issues with the upper/lower bout working together and or against one another?

[Dave Bagwill]

to ensure you don't get phase issues
Well, only that it has been done before. Plus, testing the top/rim assembly before gluing on the back, and making adjustments.
No certainty here, but I'll do what I can.

I was also thinking that a wider X would be beneficial.
Thanks!

[Daniel P]

Batson guitars have both a cantilevered fretboard and an archtop style tailpiece, right?

I don't build archtops, but I would think this would make the top behave quite differently as you don't have forward string tension on the top/bridge, and thus the function of the x-brace is quite different than a pinned bridge flat top. In a Batson the x-brace and bridge only really experience the downward pressure of the strings on the saddle?

I think we need to consider the bridge design and the box as a big part of the tonal/structural equation...

[John Parchem]

The upper transverse brace in a traditional Steel String guitar is a major structural brace supporting the neck (through stiffening the upper bout so that it will not fold under string tension. Sound hole or no sound hole. That x brace in that guitar is tall and it goes to the top of the upper bout providing way more support for the upper bout than the traditional X Brace placement. The brace needs to be tall as the effective stiffness of a brace falls off by the cube of it length. This is easy to deal with though if your brace is 20% longer make your brace 20% taller. Do you know if the guitar this top is for has other structural support to keep the heal from rolling. Like CF rods?

[Dave Bagwill]

All I have is that picture.
You've both made good points. I will be using a typical pinned bridge. As for the UTB, I'm not comfortable with what knowledge I have, as to removing it from the equation.
I suppose a neck extension would serve much the same purpose in this no-hole instrument as an UTB, along with John's suggestion of taller thinner braces? Or might the braces themselves provide enough support? Thoughts?

[John Parchem]

All I have is that picture.
You've both made good points. I will be using a typical pinned bridge. As for the UTB, I'm not comfortable with what knowledge I have, as to removing it from the equation.
I suppose a neck extension would serve much the same purpose in this no-hole instrument as an UTB, along with John's suggestion of taller thinner braces? Or might the braces themselves provide enough support? Thoughts?

If I did not have CF rods supporting the heel block I would have an upper transverse brace. Maybe the closer to vertical taller x brace could take the load and stiffen the upper bout enough to keep the top from collapsing from neck rotation> I just don't know. I do not trust it. Then you are relying on the cross grain stiffness of the top supporting a pretty good gap at the end of the heel. The top can support the gap between the heel and the UTB but without the UBT close by the span to the end of the guitar end is pretty long.