Official Luthiers Forum!

OK... This may sound naive, but please let me have your thoughts. I few weeks ago I played a Collings all body Koa dread - It was arguably one of the finest sounding guitars I have ever played, along with a very nice Martin 'Authentic' D18, and recently a Sheppard Grand Autitorium in Cocobolo/German... Although they all had their own distinctive tone, they all had one thing in common. The tension of the strings seemed very high - this seemed to lead to an immediacy in the attack of the notes, and a crisp (yet warm) 'snappiness' that made these guitars just so responsive (and highlight any poor playing technique ) Simply wonderful instruments that I lust after as a player.

Now, being a guitar junkie, I have hung out in various highend guitar shps and thankfully as a regular cuitsomer have not been kicked out, yet it has afrforded me teh luxury of playing both new and vintage instruments, most of which just make you grin inanely and avoid looking at the price because you inevitably begin to think about what you can sell (the Sheppard was a very close call... ) But in all cases where I have had this feeling the instruments in question have had this tension in the strings that have given them that positive response, with a variety of string guages.

My question is... how is this best achieved? I have seen/played guitars that have the exact sames specs , bridge pin position, bracing etc, yet some have it, some dont (play 5 D28s back to back and 1 will have it and beat the rest on tone) - Is this something that can be planned and which factors play the biggest role in establishing this response - or is it just in my head....?

Thanks in advance for any thoughts

It is in the set up . Action height is planned for an not guessed at. The pin position isn't as important as on may think. The overall height at the bridge is. A very good set up will have action at the saddle at 1/2 inch with mediums. Lights can be as high a 9/16 inch. This has to do with the resultant force applied to the bridge and saddle by the strings.
The are other details for a good punchy set up such as a radiused nut slot .Stings do not bend at a sharp angle but because of the metal properties will have a radius. This also must be taken into consideration. A proper nut slot allows the string to vibrate well. Anytime you have a string touching something it has the chance to loose energy and dampen the string.
There is a lot of physics involved in a good guitar set up , it isn't chance , luck or just happens .

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Cheers John

Great info/advice. I have still got a bit top do on the nut of one and I might try what you suggest. Any tips on radiusing the nut, or should i do a forum search?

Here's an unsolicited endorsement of Kent Everett's CD on setup - available thorough LMI. Robby O'Brien has a toot on the forum which hits the high spots. Going through these was extremely helpful for me to understand what I needed to focus on in setup.

It is very noticeable that those guitars that have had a neck reset and thus a decent action at the bridge (often with a high saddle relative to the bridge surface - and thuse usually a more acute string angle), not only have that responsiveness but obviously asyou mention in most cases a far better volume and tone... I saw a thread a while back about the string break angle to the bridgepins - was there a consensus as to whether this contributes to this 'tension effect' (I call it an effect as I dont know the figures as to whether its real or just a 'feel' ) - cant remember all the physics, but is the real tension not the same regardless of this break angle?

Frank: Concur with what John and Todd have said about set up,woods etc. I would offer up for comment that if you built two guitar exactly alike and changed only the top thickness and bracing between the two guitars you would see a difference in the snappiness as you called it. A guitar with a thicker top and lighter bracing will be less snappy then one with a thinner top and taller bracing.Both guitars can sound excellant but have is own flavor.Lets see what others have to say...?
Tom

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A person who has never made a mistake has never made anything!!!

That's interesting about the top thickness/brace height variable - I might do just that - I have recently been developing a shape that I feel I can use for several guitars and have several sister sets of Malaysian BW + Euro Spruce tops - Future project... may try this exact difference between the two with as many other factors as my skills allow being as identical as possible - trick will be to get the neck angles as close to identical as possible to be able to have the same saddle height on set up and see what impact it has.... I asked this question because every guitar I have played that had this 'tension effect' have been amazing to my ear and preference so I am looking to try and get this factor into the builds...

Having done a good bit of work on bridge pin placement and break angle , I can tell you that the pins and break angle are no where near as important as the total height. Most people look at the break angle as the angle for the resultant force from the strings. This ins't the case. The total height of the bridge and saddle , along with the footprint of the bridge and plate are more critical. The main force transfer is from the leverage of the bridge . Break angle may effect some tonal quality but only as a secondary effect and not as a primary effect.
Bridge weight , saddle material and pins all contribute to the mass of this part of the machinery and will have an effect. The key here is for you as a builder to maintain a building log to see what the effects are to your style of building. I have spent years learning to understand the cause effect relationship. It is worth your time to learn what this small area of the guitar is capable off.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

The key here is for you as a builder to maintain a building log to see what the effects are to your style of building.
Johns quote and advise is great for us all.
Mike

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Mike Collins

What john Hall said. I'm in the middle of an experiment that puts some numbers on it, but the data so far seems to be pretty clear: break angle _by_itself_ is not very important, and string height off the top can make quite a difference. The experiment, of course, is to figure out _why_.

I'll note here that the OP seems to be using 'tension' in the sense that a player does, rather than a physicist. A physicist will tell you that two strings of the same gauge at the same pitch must have the same tension: the force pulling the bridge toward the nut is the same. They may, however, have a different 'feel' (which might be called 'compliance') depending on a lot of variables, such as action height (at both ends!), relief, and possibly top stiffness. It may even be that break angle could effect compliance, and I may get a chance to measure that one too. Anyway, it's always a problem when two people use the same word in different senses, and I thought I'd try to clear that up.

Adding to Al's thoughts.......the only way to increase tension in a string at a given pitch is to increase the scale length (all else being equal). I sort of doubt that is what you are referring to though.

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Formerly known as Adaboy.......

Hi

Sorry, you are correct, in that what I am referring to is that 'feel' that certain quality guitars have whereby as you say the strings 'FEEL' under greater tension, even though from a physics perspective that is not the case - There seems to be more speed immediacy in the attack of the notes and a 'crispness' that to my ears (and naturally only IMHO) gives a more rapid and even response - I love this when I find instruments such as this and thus am looking for advice on which vaiable effect this 'feel'.

Its interesting that when measuring string tension (in true physics sense) there is no difference based on break angle, yet undoubtedly (I am sure ) those instruments that have exhibited this phenomenon are those that have had a sharper break angle, higher saddle and higher overall saddle+ bridge height.

Its this 'feel' I am looking to work on, and if there are any hints and tips on how to approach the design ....well naturally would be appreciated

Thanks for teh info so far by the way, it been really useful and interesting

If you are talking feel , there are many things that can make a guitar feel "softer " . Nut set up , action height are obvious. The neck and how stiff and how soft the top is. Here there is no one answer . I will be looking at this aspect of the post. I would like to see if someone is looking onto this .

Interesting stuff... I guess my question though with respect to 'feel' was how that 'perception' of a high string tension is created - because, to my ear and taste, I have found that guitars that have this, just have this quick responsive attack that i love - Dont get me wrong, for soft gentle picking a 'softer feel' or 'less tense' feel also offers interseting and wonderful tones, but I was interested in what makers thought contributed most froma construction perspective to that 'tense' feel. I appreciate that there are many variables, but you were setting out to try and ensure you had this, what top 5 things would you do?

I ask because I was once in a shop that had 3 x 2009 D28s recently probably all same build day - each set up OK... not great, but similar... yet one had this 'feel', this 'tension' in the strings and was far more responsive when directly compared.. looking closly, there was arguably a slightly higher saddle height and overal action, but There must have been other variables... If you had to name the top 5 to achieve this effect what would they be - assuming all else is equal?

I think this is a very significant topic, and agree with those who suggest that
setup per se in a probably a minor part of this equation.. my particular interest
is w/ 'classical' guitar, where the issue manifests most clearly on repeated notes
on a single string, with the third being 'slowest'. Wish I had something to add
other than my interest.. maybe later.

You have to look at a few things , first string gauge and material type play a significant role. To a point , the more energy in a string , the more energy available to drive the top. I think from what I see most beginner builder ask and tell me , is that you gotta get the top moving . To a degree this may be true but if that was the secret we would be bracing paper.
The top and bracing on a guitar can be as individual as children. Certainly scale length ,action height , neck and top stiffness , bracing all play a part. I do not agree that a hard feeling guitar is a better sounding guitar. It is all in the set up , and design. I have played soft feeling guitars with punch and volume . I have played hard feeling guitars that were deader than a cardboard box.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it