Setting Up & Tonal Adjustments, Part III

Close up of detail of violin, shallow dof.In Part II of this blog series, we discussed briefly how the bridge and sound post work together as a fulcrum and lever system.  In this continued discussion, we will outline a few of the guidelines and considerations I give to the sound post.

Some of this information may seem arbitrary, but is based on a combination of my training and 40 years of experience observing and setting up countless instruments from all schools, countries, and periods of violin making.

When choosing the wood for a sound post, there are a number of considerations that should be given thought.  First, one must determine the grain pattern of the top wood, i.e. how close are the annual rings, and how stiff or flexible the arching appears to be from both side to side, and neck to saddle.  It seems to work best if you can match the grain pattern of the sound post to that of the table.  But there are certainly other considerations when choosing the particular piece of sound post material for a particular instrument.

From young Engelmann spruce, to 16th century Italian spruce

I have a collection of sound post wood which varies from high-altitude, 35+ year old Engelmann spruce, to 16th century Italian spruce which came from the floor joists of a 16th century house in Italy.   I like to use Engelmann because it is incredibly lightweight and has all of the properties I seek for the transmission of vibration from the top to the back.  It is extremely fast, and allows me great variability in choosing both the grain pattern and the actual width or thickness that I have determined to be ideal for a particular instrument.  Hardness of the particular piece of spruce chosen for the sound post is also one of my many considerations when setting up an instrument.

For a 17th or 18th century instrument, I sometimes like to use my very old and well-aged wood, if I can find a sample where the grain pattern and the apparent hardness of the wood seems to match the top wood in the particular instrument I am working on.  But if I determine that the lighter weight and flexible Engelmann is more appropriate, I don’t hesitate to use it, no matter how old or how “important” the instrument happens to be.  Again, I can’t emphasize enough how important the choice of wood is to a successful result.  This is just as important as placement in relation to the bridge which will be the subject of our next discussion.

Setting Up & Tonal Adjustments, Part II

Charles Magby violinsIn my last discussion concerning tonal adjustment of violin family instruments, I touched on a number of topics, mostly dealing with different aspects of the bridge and sound post.  More specifically, one needs to understand that the bridge and sound post work together as a fulcrum and lever system, and need to be approached as such, in order to allow them to do their job in the most efficient manner.

To best understand how this system works, try to visualize the following:  When the bow strikes, or pulls on the string, the string vibrates along its length to a certain frequency.  That mechanical energy is transmitted to and through the bridge, which then begins to rock from side to side, with the bass foot of the bridge actually lifting up and then striking down on the top which then begins to move both side to side across the arching, as well as up and down along the length of the top, until those vibrations created by the vibrating string and bridge are also being transmitted through the bass bar and the entire system is vibrating to the frequency of the vibrating string.  Next, as I mentioned before, the arching is also moving from side to side, pushing downward on the sound post which in turn is also pushing downward on the back until the back is also pumping and that pumping action between the table and the back are exciting the air within the body until it is also vibrating to the same frequency and then escapes through the sound holes forming the pitch of the tone that one hears.

How a Violin Produces a Sound

What I just outlined is just the very basic overview of how a violin produces a sound.  Keep in mind that this process happens instantaneously, and all that I just discussed is what a string player or a luthier refers to as an instrument’s response.   So obviously, the choice of wood both for the bridge and the sound post, as well as the width and thickness of the bridge and the hardness, length and position of the sound post are very critical to the quality of the tone, and the quickness with it is produced.

This is why it is so important for the luthier to spend his/her life carefully studying the different schools of making with the goal of always trying understand and remember how the different concepts of arching design coupled with graduation of the plates and their attendant thicknesses affect the tone which is produced.  My master told me numerous times that the “holy grail” of violin making is the combination of those three elements-the arching, the graduations, and the specific density of the wood chosen by the maker.  Before any successful “set up” can be done on any given instrument, be it a violin, viola, or cello, these three elements must be thoroughly understood and taken into consideration.

Only a Starting Point

Even for the most talented luthier, this kind of understanding doesn’t happen overnight.  Most importantly, it must be accepted that whatever set of measurements one is taught in violinmaking school are only a starting point, and one has to be open to doing whatever the instrument is asking of you to help it work its best.

This approach is not “voodoo” violin set up and adjustment.  To be both artistic and efficient in assisting the player, a deep understanding of the elements discussed above does truly need to be assimilated by the luthier.   In our next discussion, I will offer some insight into the sound post, which in earlier times was referred to as “the soul” of the violin.  For each of these discussions, I welcome your comments and any insights you wish to offer, as I consider the learning process to be ever open-ended.