It's called a "Rebec" and predates the violin. The one in the shop was very cool (although obviously not period) and I was very tempted to buy it... until the shop owner told me the price and that she'd "oiled it" to make it "look nicer". Great. However, it did give me some great ideas re construction.
http://www.cincinnatiearlymusic.com/rebec_rebuild.html
Instead of having a carved belly, the rebec had a curved convex belly with bracing bars (see upper right) and a body carved to hold the belly slightly convex. This stops the belly caving in. I'm seriously considering this sort of design. The body will, like the rebec, be solid but carved out to give it a chamber. I've got a few choices for top wood. At this stage I'm favouring some kauri pine I came across recently that's about 50 years old. Obviously, the bass is never going to be stunningly loud acoustically, neither were rebecs. However, I reckon it'll give the bass a very definite upright sort of decay and make it nice and light into the bargain.
Here are some rough drawings of body shapes. The body will be as close to 400 wide as possible.
I'm wondering about the following...
1. what people think of the idea.
2. What dimensions people would use for the belly thickness and bracing given the tension of 6 bass strings over a 34" scale (BEADGF).
3. Neck angles and bridge break angles.
Love to hear your thoughts.
typical