String tensions

TomThumbs

The JJ DG-300 I just acquired came with a set of Argentines .11-.46. I have used their lighter tension set before (on a different guitar), but I like the increased volume and tone of the .11 high E. I have read though, that the lighter tension set allows the top of the guitar to vibrate more, as it were.

I think Martin publishes the lbs. of tension their strings produce. Does anyone have similar info regarding Argentines? More curious than anything about the difference in pressure between the two sets, if it is significant or not.

Thanks,
Tom

djangology

using the Java string calculator , for Argentines, I have calculated that on a 14 fret to the body guitar you have about 130lbs with .11s. With .10s it is about 122lbs. On a 12 fret to the body you wouldnt want to use .10s because it is only 110lbs at that point, which is too low.

A bluegrass flattop guitar with a typical set bronze strings has around 160 lbs I think.

I was playing with the string tension calculator. Consider this data:

A bluegrass guitar with bronzewound strings (scale length 25.5 inches):
E, .012" PL == 23.35# ( 0.0057gm/cm 329.6hz )
B, .016" PL == 23.3# ( 0.0101gm/cm 246.9hz )
G, .024" PB == 30.24# ( 0.0209gm/cm 196.0hz )
D, .032" PB == 30.53# ( 0.0375gm/cm 146.8hz )
A, .042" PB == 29.94# ( 0.0656gm/cm 110.0hz )
E, .053" PB == 26.06# ( 0.1017gm/cm 82.4hz )
total == 163.42 pounds

A gypsy guitar with medium Argentines (scale length 26.3):
E, .011" PL == 20.87# ( 0.0048gm/cm 329.6hz )
B, .015" PL == 21.78# ( 0.0089gm/cm 246.9hz )
G, .023" XS == 27.3# ( 0.0177gm/cm 196.0hz )
D, .029" XS == 24.32# ( 0.0281gm/cm 146.8hz )
A, .037" XS == 21.46# ( 0.0442gm/cm 110.0hz )
E, .046" XS == 18.23# ( 0.0669gm/cm 82.4hz )
total == 133.95 pounds

A gypsy guitar with light Argentines (scale length 26.3 inches):
E, .010" PL == 17.25# ( 0.0040gm/cm 329.6hz )
B, .014" PL == 18.98# ( 0.0078gm/cm 246.9hz )
G, .022" XS == 25.02# ( 0.0162gm/cm 196.0hz )
D, .028" XS == 22.36# ( 0.0258gm/cm 146.8hz )
A, .036" XS == 20.41# ( 0.042gm/cm 110.0hz )
E, .045" XS == 17.52# ( 0.0643gm/cm 82.4hz )
total == 121.54 pounds

And finally, a D hole with light Argentines and a short scale length of 25.2:
E, .010" PL == 15.84# ( 0.0040gm/cm 329.6hz )
B, .014" PL == 17.42# ( 0.0078gm/cm 246.9hz )
G, .022" XS == 22.97# ( 0.0162gm/cm 196.0hz )
D, .028" XS == 20.53# ( 0.0258gm/cm 146.8hz )
A, .036" XS == 18.74# ( 0.042gm/cm 110.0hz )
E, .045" XS == 16.09# ( 0.0643gm/cm 82.4hz )
total == 111.59 pounds

TomThumbs

Well, thank you very much for this!
So, would you consider 12lbs. a significant difference for a 14 fret oval hole? It does sound considerable, but I'm no luthier.
Not quite sure how to look at this. I know I've read about downward pressure driving the top, but then again, I've read about the increased pressure stifling the top.
Anyway, thanks again.

Tom

kimmo

I'm not sure these tensions are applicable to GJ-guitars, archtops or any other guitar type with a bridge and a tailpiece, where the pressure is formed by pushing the bridge towards the top.

On a flattop or classical (where there's a glued-on bridge) the strings are pulling the top with the weight calculated by for example the Java string calculator, so there it works.

However, if you have a bridge and a tailpiece, the pressure is only partly affected by the pulling tension. Bridge height, string angle etc. all add to the total.

In short: if you raise strings in a flattop, the pressure against the top doesn't change. If you raise strings in a selmac, pressure increases.

TomThumbs

hmmm, yeah, I see what you're saying Kimmo. Interesting. Perhaps someone who knows a hypotenuse from a hyperbole can do some calcs. But it does seem now, that the ~12lb. difference (tension) between the .10's and .11's doesn't translate to much more (downward) pressure for the top of a GJ guitar. But, perhaps enough to change the tone and timbre......

Tom

djangology

yes, the string tensions i show are by NO means calculations of tension against the top but rather they are total tension between the tailpiece and the headstock.

personally, i think it depends on how much arch is in the guitar top. gypsy guitars vary greatly in this respect. busatos have the greatest amount of curve in the top i think. i think Ciganos have good arch also dont they?? but the effect of the strings against the top probably depends a lot on that.

i think you just need to look for a guitar that seems to have a good balance of top arch, neck angle, materials, and the right string tension.

personally, on a 14-fret to the body guitar I dont prefer either .11s or .10s. they both feel fun in their own way. I play .11s because i feel like i break them less often.

TomThumbs

Yeah, I think I'll stick with the .11's.....for the tone, if nothing else. Seems like you can hit a .10 high E with a 2x4 and still get little out of it.....my experience anyway..... at least on a 14 fret GJ guitar.
I've been wanting to order more strings, and didn't want to invest in the wrong gauge/tension that might decrease my guitar's output, or stress it too much.
Thanks,
Tom

Bones

Djangology,

What's a Java string calculator?

Thanks

Bob Holo

I've done some downforce calculations in the past and then built a jig to test them. On average I found (for Gypsy Jazz strings) "10s" of various brands put a little over 20lbs down on an "average" top (this makes assumptions about the scale length, neck angle, bridge height & bombe height) and 11s of various brands put 6-9lbs more than that. Lots of guys play 10s but 'up' the high E and/or B string - not a biggie... or play 11s... also not a biggie. Where you really get into trouble is when you start putting flat-top & archtop strings on... they go up in gauge (and hence mass) fairly quick which can hurt output but more importantly... can hurt the guitar. Gypsy 10s / 11s aren't a problem for any well made GJ guitar.

But as for output - it depends on your guitar and your setup. Some guitars like 10s and some like 11s. The guitar will tell you what it wants by the way it plays. I was just playing a friend's 70s' Favino tonight and it sounded better than I've ever heard it. To be sure, it has always been a great guitar - one of the best Favinos I've ever played. He usually uses argie 10s and again - the guitar sounds fantastic like that. But tonight he had these sort of stiff Pearse strings on it and yet it wasn't noticeably stiffer in playability and it was barking like an angry dog. I typically don't play Pearse strings but his guitar was just fantastic tonight. A truly muscular sounding old Jacques Favino is a force of nature.

Bones

Hi Bob,

What's 'bombe'?

Thanks

Bob Holo

Bombe is the French word for bend. It refers to the shape of the top under the bridge on guitars that don't have a pliage (fold) like a Selmer style. So, for instance, Selmers have an area near the bridge where there is a noticeable bend (pliage) running parallel to the braces whereas on Busatos it's more of a bend or belly (bombe) where the top bends up over the bridge area but no particular place along that bend is significantly sharper than any other.