String tension - Double Bass vs. Electric Bass

[Arnold Schnitzer]

Originally Posted by Scott Pope

There's one other detail I didn't address: break angle over the bridge. Generally, the greater the break angle, the more downforce this puts over the bridge, reinforcing sustain and the fundamental. The less angle, the lesser the sustain and the lesser the fundamental.

This is overly simplistic. When you increase the breakover angle beyond the "norm", it can have different effects on different instruments. For example, a bass with a lightly-wooded top table may feel choked if the breakover angle is acute. A bass with a long upper bout will by its nature have a sharp breakover angle and will often respond and sound stronger, with more fundamental and sustain if that angle is reduced, not increased. There is theory, and there is practical application. Basses are non-standardized, so the theory is rarely spot-on; issues of "tightness", as our esteemed host mentioned above, are related to many factors, and need to be addressed on a case-by-case basis.

[Scott Pope]

Originally Posted by Arnold Schnitzer

This is overly simplistic. When you increase the breakover angle beyond the "norm", it can have different effects on different instruments. For example, a bass with a lightly-wooded top table may feel choked if the breakover angle is acute. A bass with a long upper bout will by its nature have a sharp breakover angle and will often respond and sound stronger, with more fundamental and sustain if that angle is reduced, not increased. There is theory, and there is practical application. Basses are non-standardized, so the theory is rarely spot-on; issues of "tightness", as our esteemed host mentioned above, are related to many factors, and need to be addressed on a case-by-case basis.

Yes, for double bass this is absolutely true. The OP was doing his initial experiments on electric bass, and that is where my comment was directed. My limited experience is that there is a "window" of the tension/break angle formula, which also applies any arch top instrument, from violins to arch top guitars to basses, where there needs to be enough tension to drive the top, but not so much it is choked, or in an extreme case, deformed, and that "window" is singular to the particular instrument in question.

[Jack Notestein]

All the information is very much appreciated and obviously complex. There are so many variable factors, changing with every instrument, shaping its own sound and unique, tactile response with the player.

Measuring (not calculating) the existing string tension (and string deflection at the 12th fret) on the low E string with my stock bridge will give me some numbers to begin my comparison. I'll then take similar measurements when I extend the string at various lengths back and at various degrees down from bridge level. I've got up to 3" of extra string length to try out and different ways of extending it from a shallow angle to a sharper one that puts more downward pressure on the bridge. I'm interested to see how these changes effect string pull and harmonic sensitivity as well as string tension. With the many possible ways that other components can effect change, I'm only looking at these two string-dimension variables for now to see where it leads. I'm looking forward to sharing what I find.

Thanks again.