Don Noon

Unless you are unusually skilled or talented, any tonewood from a reputable supplier will almost certainly be better than how you convert it into a violin. Rivolta, Bachmann, and others would be fine, whatever you get from them. After several instruments, you might develop a preference for particular wood properties or aesthetics; then you would see the need in-person selection. Don't worry about it now.

Sandpaper grit wears away, so you don't have a flat surface any more. For wood, I think you might get away with it (I have done it successfully a few times in the distant past, before I got tools). For flattening a plane, iron wears the sandpaper too quickly (and the iron too slowly) for my tastes. For a small plane where super-flat isn't so critical, OK... but for a large jointer plane, yeesh. BTW, I hand-scraped the tables of my 12" Jet jointer by bluing against a large surface plate and using a carbide scraper. I can't imagine doing that with sandpaper.

Much as I'd like to hang onto my Hold-Heet pot for investment purposes, divesting of unused stuff seems like a more reasonable option at this point. I'm selling the one that I've had for 40 years. Search eBay if interested.

I have done a similar test, although not careful or well-documented. The best I can recollect, cuts above the treble F did surprisingly little, and above the bass F were bad. Perhaps starting with a thick student fiddle, the cuts would be more beneficial. I also suspect that arching and grads could be diddled to give a bit of the same effect as cuts, if you want it. But I DO make my F-holes on the long-ish side, and space the eyes at 42mm on violins, somewhat based on the possible benefits.

Obviously they didn't have equipment to make Chladni patterns or Audacity to get everything perfect all of the time.

If you pre-select the listeners to be the finest players of classical music, you may get one general answer of what is "best". If you select top bluegrass players, or Irish fiddlers, you may find something else. If the listener is some random player, who knows what they'll like.

As usual, I agree with Davide, although perhaps for slightly different reasons. The arching and graduations of the Vieuxtemps are rather extreme. I'd go for something more conventional. The Plowden is asymmetrical in the extreme (most likely distortion with age), and the graduations I wouldn't copy. But I wouldn't copy anything these days, as I have much better ideas .

My official answer is: it depends on who's listening. "Better" is subjective. But yeah, on average odd arched violins probably wouldn't be as generally preferred as conventionally arched ones. One factor could be that odd arching would more likely be made by lesser makers. But you certainly can find examples of odd-looking arching that work fine, and Cremonese-like arching that are awful. Even some genuine Cremonese.

Thanks for putting all of this together. A few observations... Yes, light/thin tops make for stronger A0, as well as B modes that are lower in frequency and fairly strong (particularly B1- when getting to the limits of thinness, in my testing). The "bridge hill" range also is stronger in thin-ish tops. The peak of the transition hill can also be strong in thin tops, but perhaps not strengthended as much as A0, thus gaining in the "L" parameter. For maximum loudness (SPL), A0 doesn't appear to be as important of a factor as power in the transition hill and bridge hill... but lots of transition hill power is not generally desirable (loud and ugly). I didn't find it in your correlations, but my observation is that top arch height has a significant effect on the transition hill, with higher arching giving some attenuation in that range. Sam Zygmuntowicz independently has concluded the same thing in his "Making Copies" article available on Strad3D: "The ‘Willemotte’ and ‘Plowden’ had the highest and lowest arching respectively, and tonal comparison suggested that the high full arch of the ‘Willemotte’ could be linked with its lowered mid range and strong high-range output, compared to the low arch of the ‘Plowden’, its attendant strong mid range and relatively reduced high range. The moderately arched ‘Titian’ was placed in between, with a more even response across the low, mid and high ranges. If this type of observation holds, we may begin to get our fingers on the tone sliders that create the sounds our clients want." Those appear to be the largest of the available tone knobs, although certainly there are other factors that contribute. Wood properties and age I think are important, although quantifying the effect on tone is something I haven't seen convincingly shown as yet. Varnish, arching shape, etc. seem like that have to be in the mix as well, among others.

Funny-ish story: I just started carving a scroll today. The last time I carved anything was over a year and a half ago. In addition to having to remember the sequence for carving a scroll, I had to decide whether to push the padded disc with the pacemaker (left side), recently repaired shoulder (right side), or chest (stitched together after heart surgery). Those are all new features since the last time carving. Chest and right shoulder aren't too bad; I'd rather not push on the pacemaker.

I would worry that some random flat-looking piece of glass or stone might not be "sufficient". How would you know? But having a flat reference surface is only the beginning. I got a 22" plane, and it was so warped and twisted that I didn't want to spend days or weeks hand-scraping it flat, only to still have a cheap plane.

Ultra-flat surface plates, dial calipers, temperature controllers, precision gram scales... and the list goes on of modern stuff that's overkill and not available in the Strad era. That's no reason not to use them, unless you want to pretend you're living 300 years ago. The problem comes when getting distracted and obsessed by precision, which doesn't seem to be a big factor in the desirability of the tonal results. And that's not even mentioning CNC.

Those (A0, B1-, B1+) are assembled instrument main resonances, not plate mode frequencies (M1, M2, M5).

You could spend $90 and get one of these granite plates, supposedly flat to a ridiculous .000025". That oughta be good enough for woodworking. You might find a used one locally cheaper. I use mine a lot.

I should put stab marks in my posts so it looks more traditional/professional and less sleazy.