Introduction: A Backpacker Violin
Travels are a never ending source of inspiration and most of the times I had to leave my violin at home because it was too complicated to carry such a delicate instrument with me. Finally, I've started creating a robust and modular version of a violin that I could put in a backpack.
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The idea started during a travel in Africa while visiting different developing projects in the south of Tanzania. Later on, I've continued to develop the archetyp originally built during this trip, finding a way to amplify it, improve the proportion, keep the tuning...
After many different trials we have developed different models following some basic principles: Dimensions and proportions are the same of a classical violin.
-Violin maintainance is the same (same bridge, keys, strings...)
-The sound is generated from the vibration of wood, skin and metal (and not only from the strings)
-The instrument is modular and robust.
-The handle allows the insertion of different harmonic resonators, shoulder rests and electronic devices.
Step 1: Inspiration
While creating these violins, we let us get inspired by ethnical and ancient instruments, trying to reproduce similar resonators which can be put on our universal handle.
The instruments that have fascinated us the most are ekhtara, vioara cu goarna, calabasa, viella, and kamancheh.
Step 2: Building Up
To be able to condense all these principles in one violin we had to go through several trials. Finally we managed to create a good instrument by using the following set of materials:
-sooden stump (mainly from local wood (oak, beech, mahogany) 4x6x30cm around 5-6E
-hollow metal pole 1x40cm 3E/m -Olive, padauk
-4 tuning pin, 10-12E
-string holder 10E
-strings 20E -bridge 5E
-audio cable 1E/m
-2 piezo, 1E
-2-3 trimmers 110kOhm 3-5E Construction)
We have worked on the simplicity of the form keeping inspiration from simple geometrical forms. 2D and 3D draws are available on the projects section.
Step 3: Materials and Construction
After many tests we have sorted out the best materials for functionality
and shade combination. Some woods where taken from the territory (olive, waldnut, cherry, castanie). That allowed us to choose the direction of the cut and store the slices of wood in a dry and ventilated warehouse.
The handle is built respecting the exact dimensions of an acoustic violin and preserves the same references for the hand. It is usually made of oak, mogan, buche... The top has different forms depending on the kind of resonator it is built for. We particularly like the form of a crown pit. The total length is about 63cm. There is a reference attached to the left side of the handle to counterbalance the shoulder rest on the right side. Fingerboards preserve the original size and are usually made of padauk or olive. Generally we place a diamond shaped wood knot in the middle of the fingerboard. This peculiarity is typical of the olive wood.
The shoulder rest can be embedded between the handle and the string holder. It's a single piece designed to sit on the breast and the shoulder. One can extract it to reduce the lateral size of the violin during the transportation. Shoulder rests are extremely customizabile according to the posture of the violinst. They are designed/dimensioned to balance the total weight of the violin and to shift the center of mass towards the body to release the load on the left arm.
At first, we have tried different kind of resonators made of bamboo segments, coconuts, pumpkins or more complex forms obtained by using wood slices. The most performant resonator was a bamboo segment whose lenght was the half of the total string length. This simple resonator was extremely rich in harmonics, and substain was long lasting. Without amplification the sound is gentle and does not disturb the neighbours. We have tried resonators with parts made of skin, metal, springs, to mechanically elaborate and enrich the sound.
Step 4: Amplification
We have put two contact microphones (piezoelectric) inside all the resonators we have built. A thin layer of wax filters spurious vibrations. The microphones have different characteristic resonance frequencies, the smaller resonates aroud 2.8kHz and it is closer to the bridge, the larger resonates around 4.6kHz and it is placed further away from the bridge. The short distance between the two microphones introduce a natural reverber and the mix between the two mics construct the characteristic sound of the violin.
We have analyzed and compared the power spectrum of the sound of the electric and classical violin recording with environmental microphones. We have calculated a time averaged spectrum using baudline. In the picture an A string was played. We can see that the electric violin is rich in harmonics albeit the classic violin is stronger in the low frequency range.
Step 5: Varnishing
For the varnishing I've experimented different methods to orient around lacques, shine, soaks, dyes, stains, wax, oils... At the end I've decided for: I) sanding 40 II) sanding 180 III) sanding sponge IV) sanding 400 V) oil wiping VI) first pass of transparent shine wiped with a drape VIb) light sanding 400 VII) second pass of shine.
Step 6: Envelope
The envolope is a simple textil bag with a soft padding, the straps connect the bottom with the closure strip. The violins without shoulder rests are more compact and have no fragile parts.