Setup vs Strings Tension

klystephen · #1 10-31-2006, 08:46 AM

I want to know something about the bass setup related to the strings tension. I am using Pirastro Flexocor, the strings height are good. However, I still find the tension is not really comfortable. What the problem indeed? Do I need to change the strings or change the setup of the bass? Are there any sites that contain such information?

**Chris Fitzgerald** · #2 10-31-2006, 09:16 AM

Each player and each bass wants a different relationship of string height to string tension. If you feel that "the string height is good, but the tension is uncomfortable" for you with those strings, then the string height isn't really all that good (for you) until you change the strings. To keep the string height the same and get lower tension, the easiest thing to do would be to play lower tension strings.

There are other options tha people sometimes recommend (raised saddles, tailpiece alterations, neck reset, etc), but these are way more invasive than changing strings.

Eric Hochberg · #3 10-31-2006, 01:10 PM

"There are other options tha people sometimes recommend (raised saddles, tailpiece alterations, neck reset, etc), but these are way more invasive than changing strings."

True, but lengthening the tailpiece wire a bit to raise the tailpiece higher is easy enough and might ease the tension enough for you to use the Flexocores. It worked on my bass and is worth a try.

Jake deVilliers · #4 10-31-2006, 06:43 PM

That's a good point e.

The tension is a result of the entire length of the string, not just the section from the nut to the bridge, so shortening the afterlength will result in a softer feel to the string even though your mensure remains constant.

It will make a subtle difference to the sound.

PB+J · #5 10-31-2006, 08:53 PM

Is the tension the result of the whole length of the string? I'm not sure about that--isn't tension simply a function of the pitch and the speaking length of the string--the length from the nut to the bridge? I mean, I don't feel a difference if I have more or less string wound on the peghead--I'm not sure that changing the afterlength can change string tension. I don't see how.

I can see how the bass might play a little differently, because you might but more or less pressure on the top--maybe. But given a 42 inch scale lnth, it's going to take exactly the same tension to tun your A string to A, regardless of the afterlength, no?

Silversorcerer · #6 10-31-2006, 09:43 PM

Quote:

Originally Posted by PB+J

Is the tension the result of the whole length of the string? I'm not sure about that--isn't tension simply a function of the pitch and the speaking length of the string--the length from the nut to the bridge? I mean, I don't feel a difference if I have more or less string wound on the peghead--I'm not sure that changing the afterlength can change string tension. I don't see how.

I can see how the bass might play a little differently, because you might but more or less pressure on the top--maybe. But given a 42 inch scale lnth, it's going to take exactly the same tension to tun your A string to A, regardless of the afterlength, no?

Absolutely correct. And thank you for being skeptical of these frequent superstitions. If you lessen the tension of your strings without doing anything else, your notes will be flat. Regardless of how the tension "feels", it must be constant above the nut, between the nut and bridge and between the bridge and tailpiece. If it isn't the slots need more graphite! Lengthening the tailgut without doing anything else can change the afterlength tuning but it will not change the tension necessary for a given string with a given mensur to play at a given pitch. For reference see Mersenne's equations. I remember hashing all of this out in an old thread and all I can figure is that perhaps changing the tailgut length might make the whole string/ tailpiece afterlength system stretch easier when pulled (and this is a plausibility stretch itself), but when you let go the tension must be constant or the pitch will be off.

Jake deVilliers · #7 11-01-2006, 12:57 AM

String length of 42 plus 8 plus 3 at the top equals 53.
String length of 42 plus 6 plus 3 at the top equals 51.
I don't see how the tension could possibly remain constant.

Slabs have a 34" string length and they sure are floppy.

I'm not really big on theory, but I am willing to try things.

Try swapping your G & D strings to the other tuner and see what the strings feel like then.

PB+J · #8 11-01-2006, 05:16 AM

Strings all have a certain tension, but they also have a stiffness that's completely unrelated to tension at pitch but affects how they feel. Some strings are more flexible than others. In my experience, string diameter also has a big impact on how the string feels. It might not simply be tension that's bugging you, it might be some other combination of things

PB+J · #9 11-01-2006, 05:24 AM

Jake, if a string itself is fifty feet long, it doesn't matter--what matters is the length between the nut and the saddle, the scale length. That's what determines the tension required. If I put a set of spiros on my electric bass, they would be floppy, even though the spiros are at least ten inches longer. What matters is the scale length, not the overall length of the string. Having ten inches of string wound on the tuners doesn't change the feel or the tension at all. It's totally out of the picture. What matters is the vibrating part.

arnoldschnitzer · #10 11-01-2006, 06:02 AM

Changing the tailpiece position (and afterlength) does not change the actual tension on the bass. However, the damping changes, and is perceived by many as a change in tension and/or response. A bass may "feel" looser to the player with the tailpiece closer to the bridge, because the tailpiece is damping out more of the overtones and resonances that cause certain notes to resist. My $.02...

D McCartney · #11 11-01-2006, 08:06 AM

Quote:

Originally Posted by arnoldschnitzer

Changing the tailpiece position (and afterlength) does not change the actual tension on the bass. However, the damping changes, and is perceived by many as a change in tension and/or response. A bass may "feel" looser to the player with the tailpiece closer to the bridge, because the tailpiece is damping out more of the overtones and resonances that cause certain notes to resist. My $.02...

I wonder, does a wolf tone damper have the same effect?

klystephen · #12 11-01-2006, 08:37 AM

Thank you very much for all your suggestion and share your experience. The string height of my double bass is G 6mm, D 8mm, A 8.5mm, and E 7.5mm, all measure from the center of the strings. With these measurements, I think it should be very comfortable but actually not. I try my friend's bass with similar string height as mine. I found her is much more comfortable. Just I notice that her bass's saddle is raised. I heard that the string hardness is related to the length between bridge and tailpiece, the angle of the strings made by the bridge. Are these correct?

TroyK · #13 11-01-2006, 10:53 AM

I'm no expert, but I have a good luthier who has worked with me on my set up and I recommend it if you're concerned about it.

The angle that string passes over the bridge will definitely effect the tension on the table. The tailpiece can be raised or lowered to change that angle in the same way that raising and lowering the bridge changes that angle and thus the tension and tone.

I've also experimented with strings, which is a fine thing to do. So, strings, then string height, but if you're happy with those things, then find a luthier who will work with you on finding your set up. It's combintion of a lot of small settings and adjustments and can make a really big difference.

Just my experience and limited knowledge.

Troy

arnoldschnitzer · #14 11-01-2006, 04:28 PM

Quote:

Originally Posted by klystephen

Thank you very much for all your suggestion and share your experience. The string height of my double bass is G 6mm, D 8mm, A 8.5mm, and E 7.5mm, all measure from the center of the strings. With these measurements, I think it should be very comfortable but actually not. I try my friend's bass with similar string height as mine. I found her is much more comfortable. Just I notice that her bass's saddle is raised. I heard that the string hardness is related to the length between bridge and tailpiece, the angle of the strings made by the bridge. Are these correct?

I have a hunch that what you are experiencing is excessive fingerboard camber, or scoop. Press a string down to the fingerboard at both ends, and have someone measure the approximate distance between the fingerboard and string where the gap is widest. Also note where on the fingerboard the widest gap occurs. Do this on all four strings and report back here. Also look at the thread named "Fingerboard Scoop".

toman · #15 11-01-2006, 06:04 PM

I don't mean to hijack the thread, but it seemed dumb to start a new one for such a little question...

Where do you luthier types find a nice long straightedge for checking out bass fingerboards? Maybe I'm not using the right search terms, but I can't seem to find any online.

Ken McKay · #16 11-01-2006, 08:19 PM

Quote:

Originally Posted by klystephen

I want to know something about the bass setup related to the strings tension. I am using Pirastro Flexocor, the strings height are good. However, I still find the tension is not really comfortable. What the problem indeed? Do I need to change the strings or change the setup of the bass? Are there any sites that contain such information?

http://www.liutaiomottola.com/myth/perception.htm

robobass · #17 11-02-2006, 07:19 AM

I just want to mention that I find Flexocor to be a rather tight, thick, and inflexible string. They work best with low action and very little scoop, but I don't care for them. Have you tried Obligato? It is a synthetic string which I find to be a good compromise between gut and steel. If you want to stay with steel you might try Helicore.
Robobass

Robobass

Silversorcerer · #18 11-02-2006, 08:17 AM

Quote:

Originally Posted by Jake deVilliers

String length of 42 plus 8 plus 3 at the top equals 53.
String length of 42 plus 6 plus 3 at the top equals 51.
I don't see how the tension could possibly remain constant.

Slabs have a 34" string length and they sure are floppy.

I'm not really big on theory, but I am willing to try things.

Try swapping your G & D strings to the other tuner and see what the strings feel like then.

The only part of the length that enters into the equation is 42", which is constant in your examples, Jack. That is the part that vibrates and determines pitch. This is not theory. Ever since Mersenne discovered the relationship (17th century) physicists have called it the "Law" of strings. When they call something a law, it means there are no known exceptions to the rule. And for over three hundred years that has been the case. Until you change the length between the bridge and the nut, the tension must remain the same or the pitch will change also.

PB+J · #19 11-02-2006, 08:54 AM

That link Ken included is good--it explains in a reasonable way why there is no change in tension, but there could be a change in "feel."

Silversorcerer · #20 11-02-2006, 09:04 AM

Well I'm all for experimentation. But swapping the tuners around is only going to lead to a messy pegbox arrangement that could possibly create strings binding on each other and impede efforts to get them all in tune at the same time. Keep the strings on the correct tuners. If you want less tension you can switch to strings with less mass (lighter gauge or less dense material content). If you think the current tension is choking the vibration of the top of the bass but you want to keep the current strings and current tension, the downward force on the bridge can be lessened by using a raised saddle that extends forward of the table. This will allow the same strings and tension but reduce the component of the tension that acts on the bridge and table. In some cases this will result in a more responsive table and the playability will be enhanced as well.

And yes, PB&J, that link Ken McKay listed should be copied and made into a sticky in the strings section of the forum. Fantastic and well organized information to be sure!