String mass vs tension = volume

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Brian Evans
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Location: Tatamagouche, Nova Scotia

String mass vs tension = volume

Post by Brian Evans »

The reason I am playing around with things like string break angles and string after-length vs compliance/dynamic tension is that I want to be able to maximize sound and tone in my arch-tops while keeping a balance with string tension. Every time I try heavier gauge strings on my instruments I hear a reduction in tone quality, perceived loudness and I feel like they play worse. But when I put heavy strings on (higher mass, presumably) and tuned down a whole tone (lower tension by around 20%) I got a great result. I am trying to duplicate that result but at concert pitch. Has anyone done any work on the effect of higher mass strings and the loudness they create? I can get strings with higher mass and lower tension by looking for wound strings with a thinner core and a thicker winding, being that the core is what creates the tension. My deluded brain has this idea that if I do that for the bass strings and get the treble strings to be more compliant with the longer overall length idea, I may fool myself into being happy with the result... :lol:

Brian
Alan Carruth
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Re: String mass vs tension = volume

Post by Alan Carruth »

String pitch is a product of mass and tension, but that's the whole mass of the string, not just the core. For purposes of discussion the tension on two wound strings of the same total diameter will be the same at a given pitch. The one with the lighter core will be closer to breaking, and also more flexible, which makes a difference in the sound, but that's about it.

The energy in a vibrating string is proportional to the tension and the square of the amplitude. Going to thicker strings requires higher tension to get to the same pitch, so that's where the extra energy comes from. If you want to limit the tension then you'll have to go for higher action to get more energy into the string.

Heavier strings will have higher 'characteristic impedance': roughly, a measure of how hard it is to get them moving, and how hard they will push on the bridge at a given amplitude. Impedance is denoted by the letter 'Z' ('I' was already taken) with Z proportional to the square root of tension times mass. Increasing the diameter a little bit ups the impedance a fair amount since you're increasing both terms.

There's just no free lunch.
Brian Evans
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Re: String mass vs tension = volume

Post by Brian Evans »

Alan, part of my issue with stiff bass strings is inharmonicity, which I feel makes the bass strings played well up up the neck sound bad. Inharmonicity decreases with less stiff strings, so this is another reason I search out low tension bass strings with thinner cores. Chasing a holy grail, or tilting at windmills? I think both...
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Eric Knapp
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Re: String mass vs tension = volume

Post by Eric Knapp »

Brian Evans wrote:Alan, part of my issue with stiff bass strings is inharmonicity, which I feel makes the bass strings played well up up the neck sound bad. Inharmonicity decreases with less stiff strings, so this is another reason I search out low tension bass strings with thinner cores. Chasing a holy grail, or tilting at windmills? I think both...
I play a Chapman Stick. The bass strings are custom made to be very flexible to facilitate tapping. Emmett Chapman and D'Addario did a lot of iterations and they really work well that that instrument. It might be an interesting option.

http://stick.com

-Eric
David King
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Re: String mass vs tension = volume

Post by David King »

D'Addario make a tungsten wound cello string that has extra mass at a price. I always wanted to try them out on a short scale bass guitar but the price was daunting.
Mario Proulx
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Re: String mass vs tension = volume

Post by Mario Proulx »

One of my models has a 24" scale length and I recommend running mediums on it, because I, too, like the tone of heavier strings at lower tension. Turns out that mediums(13-56) on a 24" scale are nearly identical in tension to lights(12-53) on a 25.5" scale. I get the benefits of lowered tension
as well as the benefits of increased mass...
Brian Evans
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Joined: Sat Aug 30, 2014 8:26 am
Location: Tatamagouche, Nova Scotia

Re: String mass vs tension = volume

Post by Brian Evans »

I have often thought that the steel string typical 25 - 25.5" scale guitar shouldn't be tuned to E-E, it should be tuned lower. It seems like that tuning is a hold-over from tradition, gut or nylon strings, lightly built instruments. I think the idea of a 24" scale tuned to E-E is great, and my instruments respond really well to being tuned down to D-D with heavier than normal strings.
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