You can view our archived newsletters

online here.

       July 21-26, 2013            Oct. 20-25, 2013

While I always marvel at Mother Nature's incredible work - especially as it relates to the wonderful woods she makes available to us - I've been concerned about the storms and tornados that have befallen many of us over the past month or so, and I am hopeful that you and your families are all well and safe.

A few months ago I wrote about the importance of string-break angles and several folks communicated with me about the best way to measure the angles, and how to deal with the bridge saddle getting in the way when using a standard protractor. Well, your troubles are over. Your input and questions prompted our efforts to develop a string-break angle gauge that provides you with 14°, 15°, 16°, and 17° (17° and above is considered to be an excessive string-break angle). You'll find it listed in the products section of this newsletter. We hope you find it useful.

We've had two people who have had to move their July Luthierie Camp seats to our October Camp. So, if you are interested in attending this July, we do have room. Please contact Kali a.s.a.p.

Last February, I wrote about our precious woods being in jeopardy, and I discussed issues related to the CITES (Convention on International Trade of Endangered Species) embargo and the Lacey Act.

The CITES embargo is the result of an international treatise that was signed in 1976 and has resulted in the careful control of the importation and exportation of exotic woods (among other things).

The Lacey Act was a bill that was authored and driven by Senator John Lacey in 1900 to control the movement of endangered animal species from state to state and country to country. This act grew to providing some guidelines for the importation and exportation of exotic woods.

The woods of specific importance to us that are used in parts we produce for you are Gaboon ebony, Brazilian rosewood, and Honduras mahogany. Obtaining these woods is no longer as simple as contacting our suppliers and saying "hey, send us some wood." We understand our suppliers' compliance with these guidelines, and are working diligently with our supplier of Gaboon ebony for our bridges, fretboards, and peghead veneers, but the supply is getting tighter and material costs are rising. Unfortunately, Brazilian rosewood for luthierie is basically non-existent. And, we are now finding that Honduras mahogany for luthierie may be a thing of the past while our inventory of documented Honduras mahogany is dwindling.

We have tested two other species of mahogany that work well as a replacement for Honduras mahogany for block sets and for the mahogany necks used in F4 mandolins and H4 mandolas. While I don't think you will notice the difference, I didn't want to have a change occur in our wood products without making you aware of it. As as result of these changes you will begin to see some parts listed as "Genuine Mahogany," with an option of "Honduras mahogany" (as long as supply lasts).

As always, thanks for your continued business and the wonderful correspondence and photos we receive from many of you.
 

So much attention is given to soundboard woods and to the figure in the backboard and ribs, but little attention is given to the contribution of the backboard to the overall sound. It seems that most folks consider the backboard more for its aesthetic attributes than for its acoustical properties.

The backboard is a very important component of string acoustic instruments common to bluegrass music, and there are three basic categories of backboard constructions, each playing a unique role in the tonal properties of their respective instrument. These categories are reflector (resonator), closure (lid), and sound-producing medium.

Because of its curved shape and laminated construction, the banjo's backboard - called a "resonator"- is more of a reflector than a sound-producing member. The resonator itself produces very little amplitude, especially when held against the body. And, while it certainly plays a role in the instrument's tone (all parts in an instrument's "coupled system" play a role in tone production, but some to a greater degree), it is not a vibrating membrane like the backboard of a mandolin, fiddle, or guitar. Its job is to enclose the banjo's air chamber and to reflect energy forward - toward the inside of the head and toward the apertures. In its most basic description, it helps the banjo resonate.

On a resophonic guitar, the instrument's cone and spider assembly is so efficient and powerful that the contribution of the backboard is minimal by comparison. The backboard on this instrument does contribute to the mid- and bass-response, but the instrument can be played on the lap (damping the backboard) or supported on a strap (with nothing touching the backboard) with virtually the same results.

The backboard of the steel-string acoustic guitar contributes to the overall tone, and aids in enhancing the mid and bass frequencies of the instrument. And because of the structure of the conventional steel string acoustic guitar and the relative effectiveness and power of its soundboard, the backboard on the acoustic guitar plays a greater role in the overall sound than it does on the resophonic guitar. Of further interest on the steel-string acoustic guitar is that the backboard is typically cross braced with little or no attempt to graduate or otherwise control the vibrational modes of the backboard.

The violin ("fiddle" to many of us in the bluegrass world) is an interesting hybrid, and here the role of the backboard is very important. On the violin, the soundboard and backboard are coupled with a soundpost whose purpose it is to stiffen the soundboard and provide a fulcrum for the bridge to rock on, with one foot virtually over the soundpost and the other over the bass bar. This fulcrum effect helps to drive the strings' energy to the bass bar. However, as a consequence of the soundpost's connection to the backboard, it serves to also drive the backboard, and here we see a greatly elevated role in the backboard's contribution to the overall sound. Of further importance is the manner in which this instrument is held; unlike the banjo, guitar, or mandolin (but like the resophonic guitar) the apertures face upward and the instrument is held out from the body with both the backboard and the soundboard causing waves of compression and rarefaction to emanate up and down from the instrument (and not directly towards the listener).

By contrast to the foregoing instruments, the mandolin and mandola feature a backboard that is graduated, not braced, and is constructed lightly enough that it can be an effective tone producer. The backboards of these instruments play a vital role in the instrument's mid-and bass-response. A heavy backboard delivers a thin-sounding and very treble-voiced mandolin or mandola. A properly graduated backboard works in concert with the soundboard and enhances the mid and lower registers. And, if the backboard is tap tuned (so that you know something about its stiffness and specific pitch), the backboard becomes a critical acoustical component of these instruments. Most musicians appreciate the backboard's contribution and will hold the instrument away from their body, or they will use one of the Tone-Gards® made by our friend and neighbor Tony Pires. For the mandolin and mandola, the type of wood used on the backboard is very important. Next month I'll discuss these valuable attributes to help you select the right tone woods for your mandolins and mandolas.

Earlier in this newsletter, I announced our new String-Break Angle gauge (it is listed above in our Products of the Month section), and I mentioned that we get emails and calls on a rather regular basis from folks who have experience problems getting the desired tone from their instrument(s) only to learn that they have a severe string-break angle. The most common question we then get is "what can I do about it?" As shown in this photo, this mandolin was constructed with an excessive neck pitch that resulted in the bridge having a 20° string break angle. The instrument had very poor tone, was not very loud, and after a short period of time once it was strung up, the bridge saddle cracked.

Just to review, string-break angles above 16° will subject the soundboard to excessive download pressure from the strings via the bridge. This pressure can lead to hampered or restricted tone and amplitude (volume), broken bridge saddles, and cracked or distorted soundboards.

So the issue at hand is to understand what can be done to solve the problem.

The ideal solution is to remove the neck and reset it to the proper 5.5° pitch. But removing the neck is considered major surgery. Neck removal requires fretboard removal and this often results in a damaged fretboard and, basically, this leads to fretboard replacement.

There are two other solutions, either of which can be a saving grace. One solution is to pull the fretboard, and carefully scrape the fretboard plane at an angle. In this method, rather than changing the neck pitch, you are effectively changing the fretboard pitch. Scraping is tedious and slow, but it can be done and it means that you don't have to disturb the neck joint and the finish around it. (This method may require you to replace the fretboard if you were not able to remove it intact.)

The other solution is to remove the fretboard binding, carefully pull all the frets (we have a great fret puller tool to help do this), and then scrape and sand down the fretboard so that the surface of the fretboard plane will be at a new pitch. You can use a razor saw and cut the fretslots deeper as you thin the fretboard further up the neck - using the original fretslots as a guide. When you have re-surfaced the neck, you can route a new binding channel. Because the fretboard is now tapered, the new binding channel will start at about the same depth at the nut, but will angle down into the neck as you go further up the fretboard. You most likely will have to replace some of the inlays.

If you find that you have a 17° or possibly 18° string-break angle, these two methods will work well to help achieve to the right string-break angle, or at least get you closer to the right string-break angle. However, if you have any angle higher than 18°, you will have to resort to removing the neck and re-setting it to the correct neck pitch.

None of these solutions are really wonderful, but they do help you solve a less-than-wonderful string-break angle problem.