8 string short-scale tension question.

Discussion in 'Strings [BG]' started by Bassphemy, Jul 10, 2013.

  1. Bassphemy


    Jul 10, 2013
    My first post yay!

    Hi all! I've have got two questions.

    First question:
    What is the ideal overall string tension for a short-scale 8 string bass?

    I’ve tried a lot of different searches on Google as well as the Talkbass forums without any luck. I’ve also tried to grasp/understand the math behind string tension, string gauge, scale length and frequency, so I could calculate myself to the answer.

    I know the gauges and the scale length for my bass(Hagstrom HB-8):

    The manufacturer has listed these gauges as standard for the bass:

    G2 - .040
    G3 - .015

    D2 - .055
    D3 - .025

    A1 - .070
    A2 - .040

    E1 - .095
    E2 - .055

    and scale length is 30,75”

    I found this formula on D’Addario sites to calculate tension:

    But I don’t know the Unit Weight for the strings listed on Hagstroms site…
    From looking at different string charts from both D’Addario and CircleKstrings I see that different strings with the same gauge can have different UW. :S

    I found some other relevant info on CircleKStrings site regarding tension:

    So with this information I could (based on the hypothetical premise that the 8 string has 4 bass strings and 4 guitar strings) calculate: 40*4+18*4 = 232 lb

    However this is for 34” scale, and as I understand a 30.75" scale would have a lighter tension, so the above estimate seems unreliable.

    I tried cross referencing the bass’ standard gauges listed by the manufacturer to this chart, however I didn’t really understand this part:

    My Norwegian brain really hurts now. :S

    Any info or pointers would be greatly appreciated.

    Second question:
    So from what I understand so far, as long as I calculate the correct gauge vs. tension within the limits of overall neck tension and string tension, I could have whatever custom tuning I want right?
  2. SLaPiNFuNK

    SLaPiNFuNK Inactive Commercial User

    Jul 28, 2006
    LA California
    The Brains: FretNation.com
    You are correct that there is lower tension on the 30.75" scale instrument from a 34" instrument.

    And yes, depending on the strings construction the overall weight is going to be different so you can not compare string gauges between manufacturers.

    You can use the D'Addario tension chart as it has unit weights listed. They have 30" scale tensions listed but your tensions are going to be slightly higher than that. If you really want to figure out the different (not much) you can...


    Now as far as the ideal tension, it really depends on what you want. If you like what is on there you can get close to it by going with a similar construction string in those similar gauges. It wont be exact, but it will be close.
  3. khutch

    khutch Praise Harp

    Aug 20, 2011
    suburban Chicago
    I don't know but what I would do is to use weight data from D'Addario or Circle K to estimate the current tension. I would use CK data if the strings on the bass are round wound simply because they have data on such a wide range of gauges. I would use DA data for everything else. Match the type of the string you have on the bass to the nearest equivalent in those data tables. Yeah, it is not 100% accurate but it is as close as you can get and almost certainly close enough for what you are trying to do.

    I think what they are trying to say is that if you start with tensions for a 25.5 inch scale length then those tensions will be the same at 27, 28.6, 30.3, and 32.1 inches if you tune down half a step each time you move to the next longer scale length. Or if you start at 34 inches the tensions will stay the same if you tune up half a step each time you go to the next shorter scale length. As written that comment will hurt anyone's brain!

    Yes, that is right. Tension charts are extremely useful for two situations. The first is when you don't like the string to string tensions found in standard string sets. Tension charts let you set up the tensions in any pattern that suits you best. The other is when you tune differently from the tunings that standard string sets were made for. I tune in fifths for example so I use tension data to pick gauges that work well for fifths tunings and so far the use of tension data has gotten me where I want to be even though I often use DA or CK data to pick gauges for other brands of strings.

    I put together a string tension calculator spreadsheet that you can play around with. It should help you in your quest to set up your string tensions. Description here. General instructions here, on the second paragraph. Those links all go to the Fifths Tuning Club here on TB and if you are tuning in fifths there is a lot of information there for you and we would love to have you join the conversation.

    Once you pick your gauges SLaPiNFuNK's company, BassStringsOnline.com, is an excellent place to get strings for unusual tunings since he sells many brands and types of strings as singles which makes it possible and affordable to build custom sets for specific tunings. I know that he has loyal customers in England so I assume that he can ship to Norway as well. Circle K does that too but they only sell their own strings of course and they are the only place you can get their strings.

  4. knuckle_head

    knuckle_head Commercial User

    Jul 30, 2002
    Owner; Knuckle Guitar Works & Circle K Strings
    Your Hagstrom has a similar scale length to Bass VI, Danelectro, Hellcat and others - using a benchmark of 30-32 pounds may be a good place to start.
  5. ixlramp

    ixlramp Guest

    Jan 25, 2005
    If you want precise tensions for other scales use this:
    For scales other than 34" multiply the tension shown by
    (yourscale / 34) squared

    CKS' mentioning 35 to 45 is to give an idea of medium tension on a 34" scale, on a shorter scale a particular tension feels tighter and the minimum practical tension is lower so you could easily go as low as 25-30 pounds if you want to be kind to your fingers. The thinner octave strings are less prone to flop so those can be even lighter.
  6. Bassphemy


    Jul 10, 2013
    ixlramp, SLaPiNFuNK, knuckle_head and Ken thanks for the replies.

    I think I'm starting to get it now. Just needed that extra tilt in the right direction, and a good nights sleep.

    Checked out SLaPiNFuNK store, pretty cool.

    I used this to get a quick estimate of the overall tension. But I can't say I completly trust it. Does anyone of you guys have any experience with it?

    Here is the estimate using the StringBusters Calc.
    G 040 27.33
    g 015 18.74
    D 055 30.36
    d 025 24.72
    A 070 27.39
    a 040 34.92
    E 095 27.45
    e 055 36.73

    The tension seemed kinda low, until I read this:
    :) Thanks
    So does an overall tension of 227.64 seem ok?
    I've been tuning DGDA for a couple of years now, not full fifth tuning, but close. The tuning I wanna try out is EAEB with the option of drop D for full 5th awesomeness. Looking forward to joining the community!:D

    Going to use the string tension calculator spreadsheet when I have the time to get into it. It looks like it's great for comparing different alternatives and keeping all the numbers in order. Also kinda wanna try to tune the courses in intervals other that octaves. So the spreadsheet will definitely help.

    Thanks again guys!

  7. ixlramp

    ixlramp Guest

    Jan 25, 2005
    It's okay if the total is no higher than the stock set.

    Also, you can see the EADG strings are reasonably well balanced, but the octave strings get unnecessarily tight low down. The octave strings never need to be the tighter of each pair, their lower mass means they can be a little looser without flop or bad tone. To improve that stock set i would make the octave strings be between roughly 25-20 pounds low to high.

    I recommend using the CKS tension chart and the trick i showed you to find tensions, it's more work but less prone to error, i do not entirely trust those calculators.
  8. makz


    May 16, 2009
    I was asking myself this kind of questions a few weeks ago. I have the same bass.

    I aimed for a tension of about ~30 on all the strings, which according to my calculations, is a bit less than the stock tension.

    The idea was to tune it BBEEAADD, with piccolo strings, each pair in unison.

    In the end I didn't like the overall tension, for me it makes it hard to play, because it raises the action and creates some neck relief. I can't make the neck more straight, the truss rod on mine is maxed out.

    I then tuned it lower, AADDGGBB, and it is much better, so I'd go for a tension of about 20-25.

    I think I used .065, .050, .040 and .025 strings, but the next time I will pick .060, .045, .035 and .020 or something like that, to get that 20-25 tension, I might even go for a lower tension.