Fodera's Extended B

sargebaker · #1 06-14-2005, 03:26 PM

I wasn't too sure where to post this (here or Setup). Anyways, I was confused because I was always told that after the string breaks at the nut, extra length does not really affect overall string tension. There was an example of a Matt Garrison 6 33" scale bass on the site stating that the extended B made up for the shorter scale length "and then some". Is this true or mostly just a gimmick? What do all you other pro builders out there think?

Thanks and I appologize if this has already been discussed.

Cerb · #2 06-14-2005, 03:56 PM

A longer string will not have an affect on the tension. A certain tension must be achieved to hit the correct note.

Keith Guitars · #3 06-14-2005, 05:10 PM

This is something I've seen come up in many places...

As many people have stated (including Rick Turner in a BP article) string length beyond the bridge or nut has *absolutely NO* effect on tension.

It's simple physics: for a given string (say, a .125" low B),
tension/pitch/length are directly related:
-increasing tension will raise pitch
-increasing length will lower pitch

The ONLY way to have a tighter B-string on a 33" scale is to use a heavier string. (That might mean a .125" with a heavier core wire, making a more *rigid* string...which is different than a *tighter* one).

--------------

Now, the concession:

The fact is that some people who know a thing or two about basses are convinced that the extended B makes a difference.
The only factor I can consider that would be affected by the "extended B" scenario would be the *elasticity* of the string - that is, the amount of "stretch" available along the length of the string. An instrument with a Floyd-style locking nut would be said to have no "stretch", whereas an archtop guitar with a trapeze tailpiece and long headpiece would have a substantial amount, by virtue of the long string extension "beyond the scale".

The tension of a .125" string on a 33" scale tuned to 30.8hz is a constant. However, a bass that had 50 feet of string on either side of the bridge/nut would certainly have more material available for longitudinal oscillation. This might translate to freer vibration, and therefore clearer sound.

This is an iffy point, since this mode of vibration is probably not a big component of the sound, but it's the only variable I can see at play here...(other than psychology...LOL).

If it sounds good, buy it.

Peace,
Martin

sargebaker · #4 06-14-2005, 06:58 PM

thanks for that info. I'm a little confused as to why a prestigous, well respected company such as Fodera would (need to) misguide people like that... I'd be curious as to what the results would be in an A/B test.

BassikLee · #5 06-14-2005, 07:17 PM

There was a discussion one of the forums here not long ago, where Ken Smith said before he started building, he was modding basses, putting on baddass bridges etc. He said he'd often move the BRIDGE back a bit, as to change the breaking angle of the string over the saddle/witness point. MAYBE, and this is a HUGE maybe on my part, the extended B beyond the nut has more to do with the breaking angle over the nut than with "lenth". However, I do agree 100% that a LONG string, regardless of how much of that string is between the nut/bridge, will FEEL looser, as in easier to bend. That is simple, assume any given string can bend 3% of it's "whatever"(technical term) and return to pitch. That same 3% of a longer string equals "more". I dunno...

Lee

mikezimmerman · #6 06-14-2005, 07:52 PM

I think Martin's got it right in this case, and he's articulated very well my own theories about why the extended peghead might make the difference in "feel" (but not in "tension") that some people say they find.

Lee, I think you're right that the break angle is another factor, but in that regard, the extended peghead makes no difference--the strings all run parallel to the peghead, so they have the same break angle whether they extend a long or short way past the nut. But if you've ever played a Fodera, you will have noticed that their pegheads are angled back rather more than is typical, so clearly they've got the break angle accounted for in there somewhere!

Mike

LajoieT · #7 06-14-2005, 08:16 PM

This is one of those topics that comes up reapeatedly and is full of people who have their opinions and will not have their minds changed. (We're a bit more even tempered here in the Luthier's forum, the same topic posted in Basses will likely get closed after the second round of name calling...). The concept of the Off Scale string allowing for longitudinal oscillation or giving more stretch to the string is an interesting one and one I have not heard. I'd bet that there is something to that, but I wonder if the lengths involved in anything close to a "normal" looking instrument (as in one without a 50 foot headstock) are likely insignificant. But that's just my blind hypothesis.

The point that I've always thought held the most merit was that the "percieved" difference in the B string was more often due to other factors such as Neck Rigidity. A solid rigid neck will give a more focused feeling string because the increase in tension on the string when it is struck will not bend the neck as much, reesulting in the string being allowed to increase in tension and then fall into it's resonating pattern at the proper frequency. If the neck were not rigid enough, when the string tension increases on being struck, the neck would "give in", lowering the tension of the string, and as it fell into it's resonation, there would be something similar to a little tug-of-war between the string and the neck, which would explain why some basses seem to have a harder time settling in on the lower frequencies.

Rick Turner · #8 06-14-2005, 09:21 PM

There is mass confusion over the difference between string feel and string tension.

String stretch, and thus feel, is determined by the length of the string from tuner to tailpiece and is somewhat affected by how easily the string can stretch over the nut or bridge saddle.

However, that is not the same thing as string tension which is determined by pitch, linear density of the string, and scale length. This is measurable and predictable physics, not myth, no voodoo, no confusion for those who understand the terms they use. Change anything past the scale length like angle, coupling, distance, and you'll affect feel, but you won't affect measurable tension.

And I won't even get into the effects of string stiffness here...

Hand me some Viagra, Ma!

mikezimmerman · #9 06-14-2005, 09:26 PM

sargebaker · #10 06-14-2005, 09:58 PM

this thread kinda got over my head. I should have expected it. It's good to hear the dif fopinions and it sound spretty interesting.

pilotjones · #11 06-15-2005, 09:02 AM

For those of a mathematical bent, this spreadsheet can be used not only to calculate string tension, pitch, linear unit mass, and scale, but on tab 2 you can predict the change in force required to deflect the string sideways a given distance, with various lengths of non-speaking string beyond the nut and bridge.

String Calculation Spreadsheet - please comment