The 'Davidov' Cello - An update

July 2010

This cello was examined recently and was found to be playing well, with some increase in depth of tone and increased response.  The 16 year cellist is regularly playing Bach pieces.

Some indication of its capabilities can be heard in this sample piece , kindly recorded by the owner.

See the original article here.


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Progress

March 2010

I am continuing with general repair work and bow rehairing.

As time allows I am continuing with the construction of three Sarcconi Strads, one with a fir front.

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250 year old pine beams

January 2010

Since writing the last article I have been given some beams from a barn known to be about 250 years old. The wood is obviously not spruce from the high Alps, more likely pine, and when cleaned up and the end grain assessed I will get it sawn and make a front or two from it and see how they play.

I am also looking for some well seasoned 3 or 4 year old spruce. If any knows of such a source, please let me know.

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What qualities of wood make a good instrument ?

December 2009

There is no doubt that the density of the front is important in producing the best kind of sound. The teacher-makers at Newark School of Violin Making have established this over a period of thirty years or so. As far as I am aware, no-one has measured the density of instrument fronts made in the 17 or 18th centuries and, even accepting that natural ageing processes might change density, it is going to be very difficult to obtain data on this question.

The next best approach is to obtain some wood which is known to be old, very old, about 300 years old an make an instrument from it. There was a rumour that an Irish maker had bought a barn known to be a least 200 years old, and although of pine, he used the well seasoned timbers to make fronts for fiddles. The resulting instruments were sought after because of the fine sound they made. I wonder what the truth was ?

Nobody alive has heard a Strad as it sounded when played in the late 17th or early 18th century when the wood was relatively young, so we have no real knowledge of what the aging process has done to the acoustics. What we can say is that the Strad instruments went well with the 'newer' string tensions, elongated neck and changed neck angle.

I am looking for some very old spruce or close grained pine, i.e. cut a long time ago, to see if this makes a significant difference to the acoustic properties of a violin compared to a violin made with recently cut wood. This 'experiment' would be even more fruitful if I could find some very old maple!


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Do the 'f' holes affect the sound quality ?

October 2009

Or did the old masters get it right first time ?

This is an area that I have never seen explored.

The box of a violin, or any stringed instrument, is a 'driven' Helmholtz resonator. The original work of Helmholtz established that changing the area of the 'hole' in an non-driven resonator also changed the natural frequency of vibration; a smaller hole producing a lower frequency response.

As the containers used had essentially inelastic walls, the frequency changes must result from the changed response of the resonating air.

This is a little more difficult in violins because the body has some elasticity, having been constructed from carved wood.

I will think some more about how this topic can be developed.


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Building a carbon fibre violin

27 August 2009

The use of carbon fibre in violin making is not new; the doyenne of violin acoustics Carleen Hutchins, along with aeroplane / carbon fibre manufacturers, Hercules, had made a carbon fibre violin front for an ordinary wooden body. Their findings were published in 1975, but no instruments were ever made.

Around 2000, an advert for a carbon fibre cello appeared in The Strad magazine. Violas, violins and double basses have since been added to the range.

About that time, talking with Professor Chris Rudd (now a Pro Vice Chancellor) we discussed the possibility of making a carbon fibre violin. Circumstances delayed this, but when John Dominy was appointed to the Polymer Composites Group, the idea crystallised into a Group Development Project for 4th year students at Nottingham University.

As the project also included a design element, a summer student, Luke Forward, using a 'Strad' poster of del Gesu's Lord Wilton 1742 violin, produced a CAD-CAM program to allow accurate moulds to be made of the front. Recognising the inherent difficulties of cutting carbon fibre, design license was allowed to produce f-holes resembling del Gesu's whilst removing the intricacies. The initial front was a carbon fibre laminate with a balsa wood sandwich. From the project's point of view, there were practical curing processes to be examined alongside matching stiffness characteristics and an examination of the plates response in Chladni tests.

A wooden bass bar was added and the front was mounted on a Sacconi Strad back, ribs etc. It was this that produced the banjo-like effect when played. Another plate was chosen, on the basis of Chladni plate tests, for trial on the standard wooden back. This second trial was very successful and was included in a local BBC news broadcast.




John Dominy was subsequently interviewed for BBC Radio4, Material World and the instrument was played by Jennifer Pike, who said "it plays well and easily", but feels it needs some fine tuning. Those who stand away from the instrument whilst played, recognise its strong projection both inside and outside.

It has to be understood that this is still 'Work in progress', with a degree of fine tuning to be done, before a marketable instrument is available. For the students involved, their persistence and hard work paid off when two of the group were awarded 1st class degrees.




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The 'Davidov' Cello

16 June 2009

The cello, based on the Davidov, has now been sold to an aspiring teenager going for ARSM Grade 6.
Our 'Davidov' Cello, played by its new owner


Our Davidov Cello and its new owner


Clicking the picture will expand it to full size
The instrument has already survived its first trauma, the ravages of a house fire and the attentions of the fire brigade and subsequent damping down. There were no ill effects . . it had been placed in its Hiscox case and now it plays as well as it did before the fire.


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