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Alternate Constructions?

Discussion in 'Setup & Repair [DB]' started by turf3, Mar 27, 2013.


  1. turf3

    turf3

    Sep 26, 2011
    I've wondered if there is anything meaningful to be said about "alternate constructions" in double bass. I wouldn't want to get into discussion of whether or not there are subtle tonal effects (whether positive or negative) on world-class instruments - but what about midpriced ones? Here are some things I have wondered about.

    1) String tension is always trying to pull the neck into a bowed shape; trying to collapse the top of the upper block toward the saddle and lower block; and tending to pivot the neck about the neck-to-body joint. In the double bass, we rely on the stiffness of the body box and the inherent stiffness of the neck/fingerboard to resist these forces (around 250 lb). Wood is a material that is prone to creep under long term sustained stress.

    1.1) Truss rod in the neck, to allow adjusting out the bow that gradually forms? Certainly a standard practice in steel-string acoustic guitars.

    1.2) Adjustable neck to body joint? Not very common, but I have a steel-string acoustic guitar that has this feature: the neck is held down by a couple of big honkin' bolts through a steel plate, and the angle is adjusted by two jacking screws. Now that removable-neck basses are becoming gradually accepted, at least at the midgrade instrument level, could adjustability be built in?

    1.3) has anyone ever tried to tie the upper block and lower block together to resist string force? I imagine a wooden beam, possibly laminated, possibly in I-beam shape. If the box had to do less resisting of the string force from north to south, and was mainly resisting only the downforce of the strings against the top as transmitted through the bridge, then could the top and bottom plate be made lighter and more responsive? (I have never seen this kind of construction in any other acoustic instrument but banjo, but banjos are so different from basses that there may not be any analogy.)

    2) We all are familiar with the top bracing of a double bass which is the bass bar, with support on the other side from the soundpost. I have seen references to two sound posts, but I got the impression this was for durability when standing on the instrument and other such stunts. What if you replaced the bass bar with a second post, but planned for tone rather than durability? What if the bass bar were replaced by a bracing pattern more like what you see on guitars? What if you had two bars, one on either side, and a post in the middle to transmit vibration to the back? And so on, and so on...

    Obviously what we have now works pretty well. But it's the nature of some people (like me) to wonder about experimentation. Hopefully rather than smarty comments, people with some knowledge on various things that have been tried will comment, and maybe we can have a conversation.
     
  2. bssist

    bssist

    Jun 23, 2007
    St. Louis, MO USA
    Interesting concepts. I am not a builder, but it is my understanding that every part of the instrument vibrates to create its sound - hence mode matching. It seems to me that most of the ideas you are looking at would reduce the free movement of the structure and leave tone generation more a function of the strings. At that point, I would think it would behave (soinically) more like a giant bass guitar.

    I would think that any changes would be more in the direction of allowing MORE vibration of the parts of the instrument. I get radical tonal differences just by switching endpins from steel to hickory, oak, purpleheart.
     
  3. Matthew Tucker

    Matthew Tucker Commercial User

    Aug 21, 2002
    Sydney, Australia
    Owner: Bresque Basses, Sydney Basses and Cellos
    I think we've all wondered these sorts of things from time to time. Problem is, it takes so long to build a bass and it's such an investment in time, it's a challenge to make big design experiments in case it doesn't work and the bass is a dud.

    1.1 many makers are putting fixed carbon fibre stiffener in the neck. a truss rod in such a thick neck would probably not be effective anyway, and the CF rod works well, and no moving parts.

    1.2 quite a few makers do this; Jim Ham, Mario Lamarre for starters. Nothing has really caught on in a big way though, bridge adjusters seem to be a good cheap simple fix for most people.

    1.3 British/Australian maker John Devereaux tried this in the 1850s. But in most of his extant instruments, the tension-bar has been removed, presumably to improve the tone!
    http://arts.gov.au/resources/newsletters/art-and-culture/2010/06/devereux-double-bass
    Personally I think this idea warrants another try for fun, BUT the result would probably be an instrument with longer sustain, less damping. It wouldn't have the attack of a double bass and would probably be hellish to bow.

    2. yes, what if. What problem are you trying to solve?

    3. If you want to look at alternative construction, look at the work of Patrick Charton, Jim Hamm and Arnold Schnitzer for examples of experiments that sell!
     
  4. hdiddy

    hdiddy Official Forum Flunkee Supporting Member

    Mar 16, 2004
    Richmond, CA
    I think it's a worthy pursuit. There's no problem to solve, just a boundary that needs to pushed for it's own sake. Experiments can be fun, but yeah, DB construction in the past has been prohibitive.

    I could see if you can modularize the design so you don't have to build a bass from the bottom up every single time. I'd steal some of the removable neck designs and just focus on making different body designs. If it were possible to make the top and back easily replaceable so that you could try on different forms, reinforcements and thickness somehow.

    Sounds like a fun engineering feat to me. If only I was filthy rich.

    I think also you would have to approach it from a neutral stance when judging the sound you get. If you expect it to match up with a regular DB, you'll probably be disappointed every single time. It's probably better to just take it for what it is and decide if you like the sound on it's own merits.
     
  5. rgarcia26

    rgarcia26

    Jun 9, 2008
    Miami Florida
    Wow its great to have you back Matt we missed you...I saw a while back the basses from Patrick Charton they are in my opinion amazing basses... and I just took a look on the Jim Hamm Balsa bass great too... and of course master Schnitzer
     

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