Any thoughts on Cole Clark bracing, or others?- created 11-19-2011

Lau, Matthew - 11/19/2011.22:11:18

Ever since Kif's neck joint tutorial, I've been rethinking about how I see guitars.

During the process, I came across Cole Clark guitars. Apparently, it's some weird CNC carved top with inlet, parallel diagonal braces. There's a recess carved around the perimeter of the top. While I'm sure that Cole knows what he's doing, I have no idea how or why it works (never played one in person).

I understand about the perimeter recess (Taylor does this, violin builders, arch top builders, some flattop builders). I'm not sure about the other cut outs.

Also, I'd be curious about what you think about alternate bracing, like Mark's A bracing, Bruner's outdoor guitar bracing, etc.

As I understand it, the X bracing has worked well for a long time, but I wonder how the alternatives would work...would it be an improvement?

Hi Matthew,

Matthew,

Clay: The Taylor groove is rounded as far as I know and I doubt that would create much of a stress riser. No engineer here but it would not turn me off.

Hi Tom,

some weird CNC carved top

That about sums it up!

Matthew; in the last two years of being a member of this Forum, and having worked for many years in a somewhat isolated way..without input from other makers...I have read, researched and learned a huge amount of information on the different ways that people set about building guitars. It has triggered a totally new approach to the subject (thanks Deb!)

I come from an engineering background and am an avid observer of natural history etc etc. I have used all this in developing my instruments.

However, after many years of empirical study and the input from this Forum etc, I am convinced that the only two absolute criteria in building a guitar are 1) that the intonation is as near perfect as possible, and, 2)the instrument is comfortable to play. Any change of materials, size, bracing etc, etc will doubtless result in different tonal colours and 'acoustic envelopes', but it is the player, not the maker who will respond to these.

One of my most satisfying experiences in my workshop happens when a player picks un an Acoustic 6 (for example) and says ' Wow.. what an amazing Jazz guitar!'. Next day a different person says,' Wow...what an amazing finger-picking guitar!' and so on!! The guitar responds to their different playing styles!

The player's fingers work the strings, the strings work the top. In my opinion the top should be as free as possible to respond to the nuances of the way the string is triggered. I re-quote,'The string should be the Master and the vibrating top the Slave!' I feel that too many guitars, traditionally, are the other way round.

With reference to the bracing patterns that you mention, the Cole system looks very odd..but good luck to the guy, he's in business!

'Martin' X bracing was originally designed in Europe C.1820 (?) for gut strung guitars, and Martin's version of it was intended for Gut/nylon guitars. I have yet to find an early Martin to play as a comparison with a Fan braced guitar of the same era. (Anyone help here please?). They then made it a bit heavier and stuck steel strings on.

I have to agree with Clay that it does make the top strong vertically, however, this is IMHO totally the opposite of what is needed. The strength should lie horizontally from the bridge to take the string tension but WITHOUT preventing the up and down movement of the top...after all a guitar top is essentially a 'loudspeaker cone'!!

I have played a large number of guitars with different bracing systems, and almost without exception, they were all well thoughtout, great sounding instruments! However, most were over clearly braced!! It is amazing how little you can get away with!!

Me thinks it is all to do with skinning cats!!!! (or DOGmaS!)

Clay; with huge respect I admire your confidence in the X brace system. However, I have to admit that to me it makes no sense at all!! Am I seriously missing something here??!

Hi Kif,

I'm not saying X bracing is the only scheme that will work, but I do believe it is one of the better ones.

I am right there with Clay. I have seen a lot of guitars with top problems and I can't think of one guitar that had troubles because of the X brace. I've seen troubles from every other type of bracing, and from bad construction and workmanship, but that bracing idea has certainly proven itself.

Some nylon guitars also used and use X-brace designs, I found recently this site "Rohan Lowe" (another UK maker) who experiments a lot. I recall Jimmy Westbrook told me some years ago that he saw some Roudhloff brother guitars (two Mirecourt luthiers sons of the famous François R. who were established in London from around 1820 to...?) with that feature, but clearly closer from recent Lowe's models than the standard US treatment for steel string.

Jim Forderer, a US collector, claims on his site that his 1826 Roudhloff guitar is (I quote) the "earliest example of an X braced" one. Let us be cautious with that, we very often underestimate the age of new ideas.

Hi - "Apparently, it's some weird CNC carved top with inlet, parallel diagonal braces. There's a recess carved around the perimeter of the top. While I'm sure that Cole knows what he's doing, I have no idea how or why it works (never played one in person"

I run a full time repair business here in Melbourne, Aus. There are a lot of cole clarks here and I've been to the factory and held a sawn in half guitar and full top.

The top essentially is not braced. It is much thicker and the "braces are what is left of the top after CNC routing - similar to how some modern archtops are made. It is extremely resonant with a very full bass - it actually sounds like a mini grand piano - and I honestly cannot think of another instrument that even comes close - and I have played or repaired most of what is out there....martin, taylor, borgeois etc.

However it has a classical one peice heel. I worry about future neck resets...I am currently building a steel string with such a classical heel, but with carbon fibre flying butress arrangment a la rick turner hoping to avoid the need for future neck reset.

Cheers,

"The recess will soften the top somewhat. My opinion (humble or not!?) is that it is best used at the least flexible part of the top, that is, across the grain round the 'tail' rim. I used this from late '70s on my ABGs all the way round the lower bout rim, however the top was custom laminate not solid, and I routed three curved grooves halfway through the laminate...a bit like the suspension rim of a loudspeaker. It lowered the body resonance by about a '4th' (5 steps) and increased the bass volume considerably."

Kif,any chance you have photos of this? I'm having a hard time visualizing what you were doing.

Sorry for the late response guys.

Joseph, I'm curious about the types of repairs that are needed for each type of guitar. I believe that some of the earlier Cole Clarks are double A braced.

Kif, I'm looking forward to seeing your pictures and neck joint in person. After things settle down, I'm thinking of returning the favor. While I'm a dentist, I was raised to be an engineer. I'm also an avid observer of nature.

My approach to bracing is based on my understanding of human vocal chords. They are remarkably stiff and strong, but also flexible. As I understand, the strength of lattice bracing and double tops is that the stiffness/weight is greatly increased...allowing for a more efficient and even transfer of sound.

However, I am far from understanding the mysteries of voicing a master instrument (which is why I ask you guys!).

Alain; ref Roudhloff... I missed the opportunity to buy one of these a few years ago for $1.5k..silly me! Some where a web page suggests that there are only a couple or so left! The cross braces were very slender, and between the main bout X there were 5 thin fans. There was also a small 'finger brace' on the treble side at the apex of the X. I suspect that it was post 1830 (??) as a similar Roud Bros ladder braced guitar c. 1830 I had in the workshop seemed to be of far inferior quality both in build and tone.

Joseph; I am pleased to hear your direct experience with the Cole instruments, it is obvious that he put a lot of creative energy into his design and it somehow 'proves' that other bracings work well.

Aryeh; Below I post photos of what I was trying to describe. I did this on a 'reject' top very quickly to demonstrate...it is very aproximate with the top FAR thicker than it would be on a guitar. I hope it explains!

Matthew; Don't worry about trying to voice a 'Master Instrument'..there is really no such thing, it is a matter of OPINION!!! I have limited knowledge/experience of the (in this case) Smallman lattice top nylon strung. My first major observation was the weight, almost exactly TWICE the weight of my own Nylons. The second observation was the complete lack of 'life' in the body...the back and sides are so heavy and thick that they don't move ( I bet they are trying to, but there is too much 'mass' damping). The third observation was the instruction inside to ONLY use a particular type of string, and any 'Golpe' activity was forbidden.

Sure the guitar was quite loud, but it felt/sounded like a drumskin that 'tracked' different frequencies...it seemed to be severely lacking in tonal 'colour' variations. I realise that I may be in a minority, with some great 'names' using these guitars, but personally I did not like the 'blandness' of the tone which I felt might fail in a 'Solo' recital.

In my experience, the louder a guitar, the narrower the 'bandwidth'. With the use of amplification, I wonder if acoustic amplitude should be a major criterion!??!

Clay; OK...ladder bracing can distort with steel strings, agreed! But what was the evolution that took place to change the ladders with 'fans' (to nylon/gut), and X brace (to steel strung), bearing in mind that the X was originally used for Nylon/Gut??? The ladder obviously didn't accomodate the increased longitudinal tension of steel strings, but I feel that the X brace only goes part of the way and is still a compromise. I have had endless repairs of X braced instruments that 'buckle' between the neck-end and bridge which suggest that it isn't doing it's job properly????!

And close-up!

N.B. this is a very quick, rough demonstration with the top far thicker than normal!

I have seen the Cole Clark adverts where they show the inside of their soundboards. Interesting but it would take a lot of experimentation to find the best solution. I have noticed that some of the top makers just thin down the plate a little towards the sides.

On violins and arch-tops I carve a re-curve which does the same thing. I do mine on the inside and it's quite subtle.

But, if good old X bracing works for some of the best sounding guitars, then, I suppose that must be "one of the best ways". Except, pretty soon I am going to try a lattice on a steel string, it works wonderfully on a classical ......

Hi Kif,

Kif,

The Cole Clarke appears to have both a rounded perimeter groove ala Taylor to soften the edge as well as a narrow square edged recess into which the rims are glued. This combination forms an integral "lining" to support the rim

Kif,

Andy; I use three grooves to give more give!! I noticed in an article about tops by Somogyi that the 'rim' generates the high freqs, and the centre the lows. My feeling is that, in very simplistic terms, this may be true, but 'loudspeaker' technology says otherwise. I have always tried to make the rim flexible where required, and keep the main, more central, vertical movement of the top as light and stiff as possible...thus some 'odd' bracing!!

Alain; Yes, Rohan Lowes X bracing...very interesting, however, it is my opinion that he is trying to move too much 'diaphragm' mass with too little power from nylon strings. I suspect that if one put steel strings on one (with bridge pins!), it would sound fantastic!

The above comment about about moving 'top mass' with nylons is an area of new interest to me...three of this years 'parlour' (and smaller) guitars have nylon strings, and I am always amazed by the volume that comes out of my romantic Replicas and also the originals that come through my workshop!

I shall continue this topic on my 12 string post.

I know Miles (not met) at Kent classics...my friend Esteban plays some of the sound samples for him!