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Balanced tension strings on ABG with under saddle piezo helps volume issues

Discussion in 'Strings [BG]' started by basss, May 9, 2019.


  1. basss

    basss Supporting Member

    Aug 27, 2001
    NY
    I've been struggling to get a balanced amplified volume across the strings of my ABG which has an under saddle piezo strip pickup - a common setup for this type of instrument. The little information out there that deals with this problem pertains to acoustic guitar. Assuming that the saddle and bridge are flat most advice recommends shimming under the saddle beneath the strings with low volume. I've tried a few different ways of shimming and it did help a bit but the problem persisted.

    Then I realized that the strings that were the loudest also had the highest tension. The strings I was using had more than a 10lbs tension difference between the quietest (E string) and loudest (D string). Under saddle piezos sense the vibraton of the string through the saddle so it stands to reason that a higher tension string might transmit more vibration through the saddle. I removed the shims and installed a set of strings with balanced tension (GHS balanced nickels) and the problem pretty much disappeared.

    This might seem obvious but after googling and googling for help no one recommended balanced tension strings. I think that's because they were all dealing with guitar. I'm assuming that the tension differences between guitar strings are smaller, the strings are closer together and there are more of them so balanced tension might not make as much of a difference.

    Anyway maybe this info can help you out if you are trying to balance the string to string volume from the pickup on an abg.
     
    Last edited: May 9, 2019
    Groove Doctor, michael_t and Linnin like this.
  2. Linnin

    Linnin

    Jul 19, 2012
    Linningrad, Earth
    basss likes this.
  3. ixlramp

    ixlramp

    Jan 25, 2005
    UK
    It might be because players tend to pluck the tighter strings harder, so those strings are given more vibrational energy.
     
  4. ixlramp

    ixlramp

    Jan 25, 2005
    UK
    GHS Pressurewound Bronze are not equal tensions, the GHS tension chart shows 30 35 40 40 35 for BEADG..
     
    jd56hawk likes this.
  5. basss

    basss Supporting Member

    Aug 27, 2001
    NY
    Not in this case. I found that by plucking the D sting softer I could get the same volume as the other strings when amplified before putting the balanced tension strings on.
     
  6. chadds

    chadds

    Mar 18, 2000
    To give another view a lot of people and companies install under saddle piezos.
    It’s not a drop in and forget.
    It’s an art. A nice acoustic guitar or bass can go from sounding terrible to wonderful with careful attention to the bridge componentS. Some piezos aren’t continuous filament and have discrete elements. To cut costs a six element piezo may be under your four strings.

    Pickguard material the thin film for acoustic guitars not your P bass :) can do a job of distributing the vibrations evenly. It’s placed under the saddle. It’s also useful as a shim when seasons change.

    I’ve played and owned numerous ABGs and swapped out every kind of strings from nylon core to tapewound to EBs flat half round and round & bronze. Never had string to string imbalance that wasn’t a piezo problem. This imbalance should even show up acoustically if it’s the strings.

    I called Roger Sadowski who recommended John Warden and bam great sound. He’s done Fishman in my Guild as well as Highlander in my Dave Maize, Washburn, Guild and Martin.

    Reflecting on this it’s a part of setup.
     
    Last edited: May 10, 2019
  7. basss

    basss Supporting Member

    Aug 27, 2001
    NY
    I certainly don't have a wealth of experience with abg's and piezos so you could be right. I don't know if my solution was just luck and could not be replicated but it seems to make sense given how under saddle piezos operate.

    I will say that playing a few in the store I have noticed that amplified E strings tend to be weak and this is usually the lowest tension string on a four string. It could also be that someone who is great at setting up an abg is good at installing shims. I'm not trying to argue either, I really don't know and would love to hear from a luthier with experience dialing in abg pickups.
     
    chadds likes this.
  8. chadds

    chadds

    Mar 18, 2000
    The E can be weak because it’s just not being amplified by the body. The just piezo effect can be not so pleasing. The body needs to be enhancing the string impulse. The stiffness of the neck and the entire instrument can contribute to the sound.
     
    Last edited: May 11, 2019
  9. I’ve read about equal tension strings fixing ABG volume imbalance when shims failed to. Was about 10 years ago.

    A mate had that issue with a certain brand of ABG in his music store, I helped him sort it out. Big acoustic volume across all strings, 1-2 quiet strings when amplified.
     
    basss likes this.
  10. basss

    basss Supporting Member

    Aug 27, 2001
    NY
    Good to hear that this is a thing. I couldn't find any mention of it. My bass sounded balanced when played acoustically. I only heard a volume difference through the amp.
     
    Last edited: May 10, 2019
  11. skycruiser

    skycruiser

    Jan 15, 2019
    Texas
    I was just about to post a thread about this and found this recent thread. I'm having a volume imbalance issue with my new Ibanez short scale acoustic. The E string sounds about twice (?) as loud as the other 3 strings. Should I bother trying to make adjustments myself or take it somewhere? Could techs at Guitar Center or Sam Ash fix this? I've seen suggestions about shimming and also sanding the saddle.
    I think the tension on the stock strings is just about equal. Here's what I calculated from the string specs and guitar scale (all in lbs):
    G: 12.45, D: 14.59, A: 13.45, E: 16.29
    The E is higher than the others, but I hear no difference between the other three and they also aren't the same tension.
    Any suggestions and advice would be appreciated!
     
  12. basss

    basss Supporting Member

    Aug 27, 2001
    NY
    I don't think your tension calculations are correct. Some manufacturers publish string tensions. That's what I go by and they are usually 30-50lbs per string. You could try the short scale GHS balanced nickels.

    It's important that the bottom of the saddle and the seat in the bridge that it sits in are both perfectly flat. I don't think balanced tension will fix that.
     
    Last edited: May 19, 2019
  13. skycruiser

    skycruiser

    Jan 15, 2019
    Texas
    These are very low tension nylon core strings meant for use on short scale acoustics. The tensions for the 23.5" scale bass are shown on their site: EXPPBB190GS

    I used the D'Addario equation and string data to calculate the tension for my bass. Their equation is:

    Tension = Unit Weight * (2 * Length * Frequency)^2 / 386.4

    Units are lbs, inch, Hz. I used the equation above to calc the unit weight for each string. I then plugged my 25" scale back into the equation above to get the Tension values I provided previously.

    Not sure if I should try taking things apart to see how flat they are or leave this to a tech. I guess it wouldn't hurt to take a look at it. Just don't want to break it and not exactly sure how the pick is installed under the saddle. Is it glued in or just sitting there under the saddle piece?
     
  14. Jon Moody

    Jon Moody Commercial User

    Sep 9, 2007
    Kalamazoo, MI
    Manager of Brand Identity & Development, GHS Strings, Innovation Double Bass Strings, Rocktron
    Ah, there it is. You're using what's considered a MICRO scale bass, and not a SHORT SCALE (which is 30" scale) bass. It also requires a VERY SPECIFIC set of strings, which you've noted.

    Completely different situation in terms of strings, since what's on the bass is basically what's available, period. I'd see if GC or Sam Ash could fix the situation for you. How new is the Ibanez? As in, is it within a return policy, where you could send it back and get a new one.
     
  15. skycruiser

    skycruiser

    Jan 15, 2019
    Texas
    I've only had it a couple of months, bought new at Sweetwater. I sent an email to my sales contact there to see what he can do. I would prefer to get it repaired if it can be done cheaply. I'll talk to the local techs as well, see what they suggest or if they sound knowledgeable about this type of repair.
     
  16. skycruiser

    skycruiser

    Jan 15, 2019
    Texas
    I loosened the strings and removed the saddle last night. It was a fairly rough cut on the bottom side so I sanded it flat with 220 grit sand paper on a flat surface. It was hard to see clearly what was in the slot but it looked like a thin piece of foam, presumably the pickup is underneath. After seating the saddle and tightening the string, I gave it a try and it seemed to have no effect at all. Exactly the same as before. I'm considering swapping the E and A strings to see if it's just the string itself and not the pickup. I'm not too happy with the sound of the E string acoustically anyway, and maybe the amp is just picking up that difference in sound of the string. The E has a duller sound than the others with much more pronounced fundamental frequency (less overtones I guess). If I swap the two strings and have the same issue, does that more or less exonerate the pickup?
     
  17. basss

    basss Supporting Member

    Aug 27, 2001
    NY
    You could try a shim under the saddle of the weak string. A strip of paper, tape or whatever stuck to the bottom of the saddle to help the weak string press down on the pickup. Google to get more info. If that doesn't work it may either be luthier or different bass as there don't seem to be any balanced micro scale bass strings out there.
     

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