Violin Forum/Message Board

ollieken · Posted: Thu Jan 06, 2011 2:09 pm Post subject: Adjustable Soundpost

Seen a post on maetronet about adj soundpost someone found in a violin so i googled in adj soundpost here are the links with pic never joined the Mnet forum so i posted it here Ken

http://www.talkbass.com/forum/showthread.php?t=514306

http://www.doublebassguide.com/?p=386

Chad48309 · Member Joined: 26 Sep 2010 Posts: 110 Location: Michigan

The latter isn't a sound post at all. It's an internal clamp for gluing interiors of acoustic guitars. It even says so on the page.
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ollieken · Posted: Thu Jan 06, 2011 2:31 pm Post subject: Chad

Chad you are correct wonder if the idea is stolen from Henry Ford

Chad do you think that the (sound post) link that the centre of the post at the top is threaded

Chad48309 · Member Joined: 26 Sep 2010 Posts: 110 Location: Michigan

Though I can't imagine it doing any good for the sound quality, I believe it would have to be. A spring or something of the like would just be a horrible choice (for just about EVERY reason), and the original patent application indicates a bolt and socket. I dunno. It's an oddity, to be sure.

It's not the first of it's kind, however. There are two others, a somewhat practical, if antiquated, one from John Gould and a truly strange piece from Ernest Born. It's a weird world.
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John Cadd · Posted: Mon Jan 17, 2011 3:19 pm Post subject: Adjustable sound post

The biggest problem is not the length but the angles of the ends.You can make a set of varying lengths. The angles can be "copied externally using a C- shaped cutout to fit round the treble side of the violin.Smooth on some cling film outside the areas where the sound post will fit . You can make an "external mold " with resin blobs .Let that set hard then slip it off and use that to replicate the angles needed. Mark top and back ends first Not to be mixed up. The C shape is all one item so nothing will need adjusting.Hopefully the belly MAY have even thickness wood in those areas. Don`t take that for granted though.The post length can be measured internally with a simple gauge . Buy one of those .
Tilt the violin on it`s edge nto a position where the C shape rests over the side and hangs down vertically.Keep it still while everything dries.
******** I wrote the above 10 years ago and I`m not too sure what I meant . Basically you are better of working to a measurement and then fitting the post as one thing without trying to adjust it`s length after fitting .
If you rounded the ends of a spruce post and made two end pieces of hard wood to fit the rounded ends you could have angular adjustment within the overall length measured . A very simple (thin )cord attachment would keep the ends attached while inserting .Any change in length would be made externally with abrasives . The end angles are the difficult bit to get right .All wood (mainly spruce ) is preferable to plastics or carbon .That`s my personal feeling .

John Cadd · Posted: Mon Jul 26, 2021 1:15 pm Post subject: Adjustable sound posts

One old discussion on another site where serious makers wagged a finger against amateurs messing up the plates by moving the post while the strings were tight. I clearly remember a tv program where a professional violin repairer used his post adjuster to give the post a hefty whack to shift it , all while the strings were tuned up . Completely bad example for any players .

Michael Darnton · Posted: Tue Jul 27, 2021 4:43 am Post subject:

Do as I say, not as I do is probably more the truth on that. Done properly it is less damaging than they imply.
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Mat Roop · Posted: Tue Jul 27, 2021 11:57 pm Post subject:

Michael... "done properly" always interests me. I have never ajusted a sound post with strings tuned... Am I correct to assume "done properly" means checking first to ensure the post ends fit without gaps and that the taps are for small moves only?
What else might I be missing?
Thanks Michael... always appreciate your kind advice!

Michael Darnton · Posted: Thu Jul 29, 2021 10:44 am Post subject:

First, you have to determine whether the post fits, and how well, and in what way, then you can move it so that you are dragging a corner against the wood grain cutting a trench, or you can be sliding it as if the post end is a ramp. The first is not good, obviously. You need to always be moving in a direction that slides, not cuts! The top is much more sensitive than the back regarding this!

Finally, by squeezing the top edges in the c-bout you can open the instrument up and take the pressure off the post so that it slides easily. With my setter securely in the post, I can always lift against the top and move the bottom around with no risk to align the top so that it will slide rather than cut when pulled to its final location. Then I adjust the bottom so that it fits securely, and check to make sure the top is fitting, too. A lot of this is by feel, through the setter. This is not something you can learn instantly just because you understand my words.

I can't give direct hints except to say that if you are aware of these problems you can think about it and develop a strategy to not do them. You need to develop a sense of what's going on inside and work with the wood rather than against it (I mean that literally, not metaphorically.)

I don't know how people can adjust by loosening the strings because when you do that you upset the whole violin and it won't settle for several hours--all adjustment after that is a temporary illusion. Any upset does this a bit, but loosening the strings is the worst in that regard.
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John Cadd · Posted: Fri Jul 30, 2021 10:19 am Post subject: Adjustable soundposts

Is there a special way to shape the soundpost ends ?

Michael Darnton · Posted: Fri Jul 30, 2021 11:47 am Post subject:

So that they fit! For sure, no doming as some do, which is a guarantee of non-fitting. I use a very sharp knife with a perfectly flat and straight bevel. It is the only knife I won't use for any other job.

There are a couple of tricks to the process. I'm thinking you weren't asking that, but here's a couple of ideas.
First start by making the post too long and fit it at the center. Then through a series of tiny cuts, progressively walk it out to the right spot slowly, making sure it fits all the way out. This enables you to "learn" the inside of the violin--what areas need to be cut most every time, which way the ends of the post lean (towards the north end, always, but differently on different violins.
Second, I remove of wood that are nearly air by pressing the side of the knife down into the wood hard, compressing it so that I don't have to tilt the knife up for it to cut, but just skimming what is popping up beyond the knife edge. This way you can cut slices you can almost see through. You need a real knife to do this---a flexy Exacto blade doesn't work!
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Mat Roop · Posted: Fri Jul 30, 2021 11:54 pm Post subject:

Michael Darnton · Posted: Sat Jul 31, 2021 11:24 am Post subject:

The scissors post setter is basically useless, not having the sensitivity for the job.

Yes, it's possible to relieve most of the post pressure on the back by a combination of lifting and squeezing. There's nothing unusual about my setter except that the bending is profiled for function, not looks, straight in the middle with rapid bends at each end so that either end of the setter approaches the post perpendicularly while the stalk is square to the hole to avoid damage there. The stabbing end is sharp, in the normal direction.
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John Cadd · Posted: Sat Jul 31, 2021 12:09 pm Post subject: adjustable soundposts

This is something I`ve often wanted to ask . Is the fit of the top end more important that the bottom end ? I have always treated them equally but it`s worth asking. Close to that is , should the top position be kept the same more than the bottom end , with the bridge being closely involved ?
Another tricky question is how can you know when the top end fits properly ? If we all had cartoon eyeballs that worked outside our heads it might simplify the job.
Squeezing the sides makes me think of Christmas and cracking walnuts .

Michael Darnton · Posted: Sat Jul 31, 2021 12:40 pm Post subject:

I regard the fit of both top and bottom to be important for definite tonal reasons. Some idea of the fit can be gained by rotating the post in place with the setter; if the ends fit fully it will be difficult to spin. You can also observe what point it spins on, and this can be seen through the f-hole, easily on the bottom but also visibly for the top. You can remove the post and see how completely the ends of the post are burnished and where, and this can be refreshed back to unburnished with a light tongue lick. The fit changes slightly under string tension and with time if the instrument is a new one.

Looking for a fit with eyeballs really doesn't reveal much--1/1000" of is misfit is a misfit (close doesn't count. . . a gap is a gap.)

In my work I find a lot of posts that must have fit pretty well initially, but then were batted around to some place they were never intended to go. Lots of times just putting the post back where it originally was fit gives a big boost in the quality of sound. In my experience, fit is essential, the first order of business. In my long experience messing with this, the "magic spot" is basically just BS--what really happened was that the "adjuster" batted the post around until it happened to fit by accident, and put a pencil circle there to bless that spot. I've seen violins from real shops that have as many as four circles marked. :-) When the post fits, especially on the back, the change is genuinely magical, but it has nothing to do with that specific spot.
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