This site has something for you if you are either making a violin or you want to improve a low cost violin or viola.

By tuning the top & back plates you can get a good instrument that responds well to the bow and that can sound like a £1500 instrument.

 This site available in all the major world languages here at Google translation in French, Spanish, German or Greek  ....

So, what is this site for?

This site is for people who are making a violin or viola, and also for those who want to modify a low-cost and poor-sounding instrument to dramatically improve its tone and playability.

I’m not trying to sell you anything here. Really. I believe strongly in the ‘Wiki’ idea: I feel a need to communicate what I know, so that’s what I want to do for other amateurs. What I ask in return is to hear your story, so please comment in my blog, or better mail me back to let me know what you’ve learned in fiddle making!

Tap Tones for the front and back of violins.

The pieces of wood that make up he front and back of a violin are called ‘plates’. You can reduce the tap-tone frequencies of these plates using a thumb-plane and scraper when you remove wood from the inside of them, and you can measure these tap tones as you reduce the wood thickness using a microphone and your home computer so that the violin (or viola) will sound really good. As well as thumb plane and scraper you’ll need some kitchen scales and a thickness gauge. You can then be confident that your first or your next fiddle will sound excellent! Or perhaps you could also improve the quality of sound of low-cost, poor sounding violins as I do!

This isn’t my work really. It’s using, summarising and building on the years of work others, the great names have done over the last 60 and more years. I have no problem with standing on the shoulders of others. I’m an experimental researcher by inclination and training: ‘try it!’ I say. And I love reading and learning what others have written. .I hope you benefit.

Good tone: the search for the grail.

At the heart of getting good tone from a violin is matching the front and back plates, with just the right properties of stiffness and weight in both. The plates’ tap tones are a measure of the stiffness properties of the plates. What this do is show up the quality of the wood itself, especially the spruce of the front or belly. So don’t just use any old wood. Use good old wood.

By setting these tap tones to chosen frequencies, as well as matching them front and back, almost any factory violin can have its tone dramatically improved, whatever wood it is made from. Have a look at the example violins (and violas) on the ‘Violin viola examples’ ref. page.  For interest I’ve also included pictures of what the best makers did over 300 years ago with some pictures of the outstanding instruments at the Ashmolean Museum, Oxford, UK. Do see them in person if you can.

The tap-tone method outlined on this website allows you to choose the tone you get too. It could be a ‘student’ tone for easier bowing, or perhaps you want a ‘solo’ instrument tone with harder bowing, but very powerful, and suited to real solo work. My personal preference is for ‘chamber’ and ‘orchestral’ tone instruments midway between the two: easy to bow, and flexible in use, suited to an Irish pub session, a quartet or in a symphony orchestra.

Limitations: you need craftsmanship too

This however is not a cure to all human suffering. Much or most of a violin’s quality of sound derives from just ‘good practice’ in its making. There is no substitute for proper, patient, practiced craftsmanship and artistry in the making and modification of an instrument. It should be, it must be a work of art! I cannot begin to teach any of that. I can only help with some of the science and engineering aspects. Go to a craftsman for craftsmanship, and set aside some years to do it.

Tuning the plates

Plate tuning can help make your first or your fiftieth violin a good instrument - a fine reward for 10’s of hours of work. And it is not at all difficult. I personally mostly use this method to improve the tone and playability of factory-made or damaged fiddles, such as ones with bad soundpost cracks.

Significantly, I have found a way of quickly measuring Mode 2 and Mode 5 frequencies of violin backs and the back’s weight, without removing the back from the bouts (sides and blocks). So using a short knife and warm isopropyl alcohol / water I remove just the front and fingerboard to work on the back to set up the back’s ‘stiffness factor’, and then I modify the front to match it.

The Mode 5 of a back plate is reduced by about 15%, but sometimes splits into 2 frequencies up to 40 Hz apart, usually either side of 300Hz.

Mode 2 of a back in the bouts is only slightly increased, but the neck (with no fingerboard) has a resonant frequency at almost exactly the same frequency, so we have to move the neck’s resonance out of the way!

Get in touch with me if you want to know more.

If a back is good and with specially resonant tap tones, carving a brand new spruce front can also give you remarkable results: but you have to start with good seasoned spruce for the belly though!

Arching and thicknesses

If you want to know what arching and thicknesses to use for the plates, have a look at this page. I have now included 2 figures that show how to thin plates to get Modes 2 and 5 just where you want them. This data is from Acoustics for Violin Makers by Erik Jansson in “Chapter V: Vibration Properties of the Wood and Tuning of Violin Plates”, and here is just page 25 extracted from it, with a scheme to gradually reduce thicknesses of plates in an appropriate way while keeping Modes 2 and 5 under control. This series of papers by Erik Jansson is a key reference work on acoustics and the violin: and it’s free! He used to work with Carleen M Hutchins (CAS) and really knows his stuff. Have a look on the links page too.

History: let’s start at the beginning

Every journey begins with but a single step, and every organization begins with a single member. That’s me. My committee meetings always run without a hitch. I’ve always wanted a Stradivarius or Guarnerius violin, but somehow I can’t seem to muster that first £ million. I played a Guarnerius violin once, and it spoiled me: how could I, that bowing arm be making that fabulous sound? That sound, that’s a bit like a professional soloist on a CD? Well, with all the arrogance I could muster as a qualified engineer, I decided if I couldn’t buy one, I’d have to make one. And of course, I know that as soon as I get a Strad then my amateur scratchings will be instantly transformed into something truly wonderful ......

Carleen M Hutchins, and the CAS.

Over the years, while trying to make some awful violins sound better, I needed a rationale to this mending and tinkering. So my long-suffering wife bought be the collected works of the CAS (Catgut Acoustical Society) for Christmas two years ago. A remarkably lady called Carleen Maley Hutchins co-founded the CAS nearly 50 years ago, and I remember her article well: my mum showed it to me in the early 60’s when it was printed in Scientific American (Nov 1962). You can get back-copies if you do a web search. A later article by her in 1982 I think can be found here on a Russian website, which I’ve put into a .pdf file here. The excitement of that approach stayed with me. She died this year (Aug ‘09) at the grand age of 98, and her obituary was published in the LA Times. What a lady!

Traditionally violin makers tune the front and back plates around an ‘F’ to ‘F sharp’ tap tone**. Tap-tone methods has been around for well over a hundred years (see footnote) and probably very much longer. Unfortunately factory-made fiddles, all that many of us can afford, have never even heard of ‘tap tones’ or even suffered much care in manufacture. Indeed many of these fiddles have so much wood in the back that if burned they could heat a small home for an evening.

The role of the home computer

What has changed over the last 5 years is that the ubiquitous home computer (right), used with a cheap microphone, has made available to us methods for measuring tap tone frequencies very quickly. It takes me a minute or so to measure the tap tones of a violin plate. Carleen would need perhaps an hour, and Signor Antonio Stradivari ? Well he needed a very well trained ear and maybe a a ‘standard’ wooden rod to tap for comparison. A good ear helps these days, but is not essential.

First I found that Carleen’s methods of adjusting the tap tones of front and back to an octave (1:2 ratio of Modes 2 and 5 frequencies in both) just did not produce really good fiddles: They were better, but still not very good. I think it’s because the wood for factory fiddles, especially the fronts, is not good, low density, prime-choice wood!

Makers can pay as much for the wood as some might pay for a violin outfit: Simeon Chambers has a good range of wood at reasonable prices. He suggests the light Englemann spruce for bellies, with a density (specific gravity) of 0.34 to 0.38, which is much less than than normal European spruce at 0.45, but European makers still seem to prefer Bosnian Spruce or its like.

Dr. Nigel Harris

A year ago I came across an article by Dr. Nigel Harris that seems to be the next step in the mysterious connection between the tap tones of a violin’s plates, its playability (the violin’s is ease of bowing), and a real quality and depth of sound. In addition, as Dr. Harris puts it, it can make a given tone reproducible, violin to violin!

Dr. Harris, who sells some seriously good (and pricey) violins, at Harris & Sheldon (violin.co.uk) links the plates’ Mode 5 (called the ring tone),  Mode 2 (the ‘X’ Mode), and now also the weight of the plates in a formula that yields what he calls each plates’ ‘Stiffness Figure’. His work on 1000 + violins shows that if the front and backs have a similar ‘stiffness’ then a good fiddle will result. It will sound good, and similar to other fiddles with the same matched plate ‘stiffnesses’.

 What I do here is broaden Dr. Harris’s work a little, combining Carleen’s work on Student /Amateur / Orchestral and Solo tones with Dr. Harris’s so that I can pick and choose what ‘kind’ of tone I want. Here I give a method for applying the technique, and I’ve verified that it works by modifying more than a dozen violins and violas of all types so far, and I am adding examples of them to this web site: have a look at this page . I have also modified Dr. Harris’ method for plate Stiffness measurements to take account of the effects of the edges of the plates.

There are limitations to Dr. Harris’ work (vide this page revealed by Joseph Curtins article on Strads), but this modified method applied to any old violin seems to work far more consistently than Carleen’s M Hutchins’ CAS’s ‘octave’ Mode 2/5 relationship of the last 50 years.

What this is all about: making a £75 ($150) violin sound like a £1500 ($3000) violin

So this web site is all about just how to measure tap tones and how to apply Dr. Harris’s ‘plate stiffness factor’ either to help you make a new violin, or to modify an existing and poor-sounding £80 ($120) factory fiddle to get it to play and sound like a £1500 ($2300) violin. Later I will suggest that Dr. Harris’ method for compensating for the weight of each plate actually compensates too much, and it needs to be modified somewhat: but we’re getting ahead of ourselves here.

So have a look at the various pages here. In particular, have a look at how to easily measure tap tones, and how to use them to get matching front and plates even when using less than the best spruce and maple. I’ll show too the various stages of how I modified some constructionally challenged instruments.

You can’t do much damage to a £40 ($60) violin: at worst it’s £40 of experience. But Warning: but do not try this on your Concert Strad: it will seriously damage your father’s favorite violin.

Feedback: tell me what you think, and tell me about your experiences.

Let me know what you think of this site and its contents: violin plate tuning seems to evoke strong emotions in luthiers ...... so let me know what you think: now ! It’s all work in progress, so I’ll include your comments, but no promises though.

So please Email me, or comment here in my blog ......

PS: Amusingly, this website is also available in the Russian language, but I’m still looking for the Russian for “tinkerer”. Perhaps any native Russian speakers could help out here. It is also available in all the major world languages here at Google translation in  French, Spanish, German or Greek  ....

 

** F# is 370 Hz, F (natural) is 349.2 Hz, and E is 329.6 Hz. The reference here is to Ed. Heron-Allen’s book on violin making of 1885-6. Believe it or not he refers to Modes 2 and 5 and ‘nodal lines’ on p.133, and tells the reader how to visualise them using sand and a bow!  Yes, that’s from 125 years ago.