Salve Håkedal

Relating to the original posting, I recorded a knock against the left bridge foot position first after carving the channel and then after finishing the fluting (concave part of arching) on a closed sound box with the sound post in place. As I don't control the impact of my little hammer very well, the amplitudes can not be relied upon. I don't control the hammered spot very precisely either, but the lower resonances should not be affected by this, I think. Removing the wood from the concave part of the arching between the channel and the rest of the arching is actually a rather drastic thing when talking about thicknessing, isn't it? Grams is removed from both back and top. But most resonances sinks just a little bit. My tactile impression is that it takes less impact from the hammer to excite the body. Which is of course only logical and to be expected. Sooo.. : what did I get from this hammering activity? Answer: a break from more productive work :-D (The instrument is a Hardanger d'amore, which in this context can be considered a very small viola (38.5cm))

The knock to the instrument is in different places with no strings and then after set up. It's no longer possible to knock against the middle of the bass bar with the bridge and strings in place. Knocking to the bridge activates the high frequencies a lot. I don't think I have that for an instrument that was not altered in between. But here is one that had an accident a few months after delivery and came back for repair (gluing a crack from end to end of the table). Though it probably shows my inconsistency in measuring method better than it shows the actual changes to the instrument, you can all have it:

Yes, damped: And the fiddle is held at the neck by the saddle, approximately. The recorded sound file is 0.2 second long.

There is 3 stages in the graph: first the unvarnished fiddle body alone, with the soundpost in place, then the varnished violin with neck and pegs and, of course, sound post in place, then the fully set up instrument. (If you are interested in more stages, like fluting in only the back or top of the body without neck but sound post inserted, I have it. Or the change after the last stage: adding the sympathetic strings, I have that too. But as I state above: I can not really say that I have had much practical use for it.)

I have been tapping and recording frequencies for over 10 years (100+ instruments) in many stages; from wood billets to the set up instrument. I find it interesting. But how useful it has been is hard to say. What I do know, is that is has prevented me from developing badly funded and possibly harmful pet theories. And that's good! Beware: I'm no scientist and my measuring methods/routines are sloppy. Below is a plot of a hardangerfiddle. For "No neck" and "With pegs" I tapped where the left bridge foot will come. For "Fully set up" I tapped from the side to the top of the left bridge edge. (Hardangerfiddles usually have thinner strings as well as somewhat thinner plates than most new violins. I don't think the added sympathetic strings takes the total string tension up to the tension of a normal violin string set.)

I've had dewaxed and bleached shellac (from Kremer) for quite a few years that still dissolves well in alcohol. Once dissolved, however, the shelf life is short. (Therefor, I make it fresh for every new fiddle.)

I'm curious about the picture above. It looks like endwood, not the surface of a fiddle table! Am I wrong?

Don is right again!

OK, Martin!

I have zero experience with chinese hardangerfiddles. Those that I've seen on pictures seems terrible uninformed about the norwegian tradition! What Cerulean writes about norwegian hardangerfiddles makes good sense to me. I don't quite agree with Martin ... setting up a hardangerfiddle , for a player in solid tradition, at least, is drastically different from setting up a violin. The traditional playing technique is very different. It's not a given that even a top class straight violin maker would do it properly. (Maybe Martin was not thinking about the the setup, though. Anyway, I suspect that chinese makers are less informed about good hardangerfiddles than they are about violins. But I repeat: I have no experience with them.)

I too use a fretsaw. Then the same narrow knife that I use for purfling and also the chisel for purfling to cut the crossgrain end of the slot. Then finally a needle file to round the edge of the end off.

I remember Michelman advised to use fresh colophony, because it will oxidize with time. I know you don't make the Michelman varnish. But wouldn't your colophony change over such a long time?

When you are adjusting the sound post, you are at the final stage and can hear the result directly with your ears. I think it is interesting to see a graph of what a knock on the bridge will produce and I save lots on my disk. But what matters at this stage is playability and the sound in your ear. Everything else is a detour.

Approximately so, yes. It's not a strict standard. I.e. my fiddles have neck stop at 112mm and body stop at ~185mm. (String length close to 300mm.)

Most of this is way above my head. But regarding torrefied wood giving brighter sound: Does torrefying alter the ratio of stiffness between longitudinal and radial direction in the wood (trunk)?