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String tension chart

Discussion in 'Strings [DB]' started by bassist14, Feb 1, 2006.


  1. bassist14

    bassist14

    Oct 17, 2005
    Germany
  2. TroyK

    TroyK Moderator Staff Member

    Mar 14, 2003
    Seattle, WA
    I'm using Jazzers and have strong opinions/preferences about what I perceive to be tension. But, there's a science behind answering your question that I don't have a grasp of </disclaimer>

    The gauge is between Spirocore Weiches and Mettiels and I perceive the tension to be in between as well. I've played all of those strings (and many, many more), but not on the same bass, so it's not an authoritative answer on my part.

    -tk
     
  3. bassist14

    bassist14

    Oct 17, 2005
    Germany
    after reading the replys i checked the link in post #1 - i did not work.
    but i made a pdf of the chart which i post here, together with two others that might be posted somewhere else, but i hope they can be useful for someone
     

    Attached Files:

  4. bassist14

    bassist14

    Oct 17, 2005
    Germany
    two more charts
     

    Attached Files:

  5. Jake deVilliers

    Jake deVilliers Commercial User

    May 24, 2006
    Crescent Beach, BC
    Owner of The Bass Spa, String Repairman at Long & McQuade Vancouver
  6. neslofalo

    neslofalo

    Mar 3, 2008
    will the string tension influence the action the same way it does on an electric?
     
  7. Francois Blais

    Francois Blais Supporting Member

    Dec 11, 1999
    Québec, Canada
    Depends on the instrument!
    A given bass may choke with higher tension, or may not sound full with lower tension.
    No definitive answer to this question, then.

    Best regards,
    François
     
  8. CPike

    CPike

    May 28, 2005
    Dallas, TX
    I think what neslofalo means is how does string tension affect the height of the strings above the fingerboard on a DB compared to EB. As a player of both, as well as guitar, I can say that the impact is negligible. I'm sure it can be measured, but since the ebony of a DB fingerboard is so dense and thick compared to the standard rosewood of an EB you wouldn't feel it in terms of string height. You would, however, feel it in how much resistance the string has as you press it down with your LH.

    The string height will vary more as the weather and humidity changes. The DB neck and fingerboard are just very rigid. I have ebony fingerboards on both my fretless and my 5 string fretted EBs and I never mess with the truss rod in either one when I change string gauges. My hollowbody guitar has an ebony fingerboard as well and I can switch between 10's and 13's and never adjust the truss rod. Now, whenever I play an EB with rosewood or maple fingerboards it just feels so "spongy" to me. Ebony, man, ebony...

    Chris
     
  9. anonymous12251111

    anonymous12251111 Banned

    Apr 6, 2007
    what is the tension of pirastro flat-chromesteels?

    thx
     
  10. bassist14

    bassist14

    Oct 17, 2005
    Germany
    well, according to http://baen.tamu.edu/users/rel/personal/BassStrings.html
    its an easy calculation :):
    (i discovered right now for the first time that you can click on the tabs at the bottom of the page (which is based on an excel-sheet, i think) on the "105cm" "110cm" and "string tension" tabs
    ("9.80665 m/s^2 = acceleration due to gravity" is my favourite:))


    Calculation of string tension

    f = 0.5 sqrt(T/(9.80665*p*l*a))
    9.80665 m/s^2 = acceleration due to gravity
    f = frequency [Hz]
    3.14159 = pi
    T = tension [N]
    p = effective mass density [kg/m^3]
    l = scale length [m]
    a = cross sectional area of the string [m^m] = (pi*d^2)/4
    d = string diameter [m]

    Musical Note Frequencies (Hz)
    Equal Tempered Scale
    1 2 3 4 5 6 7 8 9 10 11 A 27.5 55 110 220 440 880 1760 3520 7040 14080 Bb 29.13524 58.27047 116.5409 233.0819 466.1638 932.3275 1864.655 3729.31 7458.62 14917.24 B 30.86771 61.73541 123.4708 246.9417 493.8833 987.7666 1975.533 3951.066 7902.133 15804.27 C 32.7032 65.40639 130.8128 261.6256 523.2511 1046.502 2093.005 4186.009 8372.018 16744.04 C# 34.64783 69.29566 138.5913 277.1826 554.3653 1108.731 2217.461 4434.922 8869.844 17739.69 D 36.7081 73.41619 146.8324 293.6648 587.3295 1174.659 2349.318 4698.636 9397.273 18794.55 D# 38.89087 77.78175 155.5635 311.127 622.254 1244.508 2489.016 4978.032 9956.063 19912.13 E 20.60172 41.20344 82.40689 164.8138 329.6276 659.2551 1318.51 2637.02 5274.041 10548.08 F 21.82676 43.65353 87.30706 174.6141 349.2282 698.4565 1396.913 2793.826 5587.652 11175.3 F# 23.12465 46.2493 92.49861 184.9972 369.9944 739.9888 1479.978 2959.955 5919.911 11839.82 G 24.49971 48.99943 97.99886 195.9977 391.9954 783.9909 1567.982 3135.963 6271.927 12543.85 G# 25.95654 51.91309 103.8262 207.6523 415.3047 830.6094 1661.219 3322.438 6644.875 13289.75
     
  11. Uncletoad

    Uncletoad

    May 6, 2003
    Columbus Ohio
    Proprietor Fifth Avenue Fret Shop. Technical Editor Bass Gear Magazine
    I'm not so sure about calculating the tension of a given string from external measure of dimension.

    The core makes a huge difference on string tension. Wind the same diameter string on a slender core and the tension won't be as high as a thicker core, all other things equal. Moreover the makeup of the material in the core and the wrap, and how it is twisted or wraped can all make differences in string tension beyond what you see in just diameter.
     
  12. Jake deVilliers

    Jake deVilliers Commercial User

    May 24, 2006
    Crescent Beach, BC
    Owner of The Bass Spa, String Repairman at Long & McQuade Vancouver
    I'm with you Phil - there's no way to make that an accurate predictor of tension. The core, inner wrap and outer wrap change things so much.
    That giant Gamut A string of Knebel's has less tension than a Spiro Weich, for instance. Less focus too, sadly, but it looks fantastic! :)
     
  13. relacey

    relacey

    Sep 18, 2004
    Since we're an international forum I thought I should use the SI appropriate value for gravitational acceleration :D. Let's just call it g for now.

    <NERD ALERT - Skip this if math makes you woozy>
    Starting with the original equation

    f = 0.5 * sqrt(T/(9.80665*p*l*a))

    f = frequency [Hz]
    T = tension [N]
    p = effective mass density [kg/m^3]
    l = scale length [m]
    a = cross sectional area of the string [m^m] = (pi*d^2)/4
    d = string diameter [m]
    pi = 3.14159
    g = 9.80665 m/s^2 = acceleration due to gravity

    If you're not familiar with spreadsheet math, d^2 is d squared, / is division, sqrt() is square root, and * is multiplication. If you rearrange the equation so you're solving for tension you get

    T = 4 * f^2 * g * p * l * a

    and since area is pi*d^2 /4

    T = pi * f^2 * g * p * l * d^2

    so for a given frequency as the length or diameter increases, the tension increases. Note also that since tension is a function of the square of diameter and frequency, small changes in either of those parameters will result in big changes in tension.

    The fly in all this ointment is that you need to know p, effective string density. A more dense string, e.g. steel core versus a less dense string, e.g. nylon core, will have more tension. If a string was a wire made of a pure material this would be known, but strings are complex little buggers! Wrappings, core composition and construction, etc. make this data that you need to determine empirically for each string. This is also why some gut E & A strings are wrapped, increasing the effective density while decreasing the diameter. This allows you to maintain a desired low tension and low frequency without having to accommodate a big-ass string.

    In the tension chart, if a tension value was given for a string at known frequency, length, and diameter I back-calculated the effective string density. With that data point I could calculate tensions at different frequencies or scale lengths. Without some way to get p I agree with Jake and Phil, you can't estimate tension based on dimensions alone. It would be really useful to collect a table of effective string densities but I suspect we would be running into proprietary areas for the string companies.

    And of course, none of this has anything to do with how the string will sound on your bass.
    </NERD Mode>

    If you skipped down to here, just know that the above is nothing short of brilliant and probably deserves the Nobel Prize for string theory. :bag: Plus, I agree with two of our venerable TBDB members so it must be right! :D
     
  14. Jake deVilliers

    Jake deVilliers Commercial User

    May 24, 2006
    Crescent Beach, BC
    Owner of The Bass Spa, String Repairman at Long & McQuade Vancouver
    Brilliant exposition with an infallible conclusion! :D
     
  15. does anyone have info on the tension of Pirastro Evah Pirazzi Regulars and EP Weichs?
     
  16. CrazyZeke

    CrazyZeke

    Dec 29, 2009
    Eastern WV (DC suburbs)
    Endorsing Artist - Phil Jones Bass
    Good question! I just thinking about the missing EP tensions myself this morning. The reason is that I trying to minimize the neck bow/relief issues I've had on my Englehadrt EG-9. Spiro weichs work great, mittles choke my bass.

    Always on the seach for "that" right tone...that works mechanically with my hands!
     
  17. My apologies if this has already been answered, but I haven't been able to find it anywhere. Does anybody have a comparison of tension between the Spirocore Weichs and the Solos (tuned to orchestral pitch)?

    I have a set of Mittels and they sound fantastic, but my left hand keeps telling me it would like less tension.

    Thanks!

    -Cory
     
  18. Jake deVilliers

    Jake deVilliers Commercial User

    May 24, 2006
    Crescent Beach, BC
    Owner of The Bass Spa, String Repairman at Long & McQuade Vancouver
  19. relacey

    relacey

    Sep 18, 2004
  20. knuckle_head

    knuckle_head Commercial User

    Jul 30, 2002
    Seattle
    Owner; Knuckle Guitar Works & Circle K Strings
    Best indicator of tension would be to weigh - physically - each string in question and discover each string's weight per inch. Expensive process as they'd need to be ball-end free.

    Then it becomes a matter of rigidity to define comfort.

    In designing electric strings it is a constant point of amusement to have a thicker string actually have less density/mass than a thinner formula. It's the little things... ;)
     
    LowB-ing likes this.