Flatback vs. Roundback

Discussion in 'Basses [DB]' started by Mike Goodbar, Oct 22, 2001.

  1. Can any generalizations be made concerning the sound/projection/health/playability of flatback vs roundback basses, or are there too many instrument-specific variables?

    For example, I've heard/read that flatbacks crack more often and have a more "forward-projecting" sound than roundback basses.

    Any other thoughts?
  2. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator Gold Supporting Member

    Oct 19, 2000
    Louisville, KY
    Although I can offer no actual facts to back up my feelings on the matter, I prefer roundbacks. Maybe I've just played one too many flatbacks with weird buzzing noises coming from the bracings, or maybe it's just that I think roundbacks look better. YMMV.
  3. Ditto
  4. mchildree

    mchildree Supporting Member

    Sep 4, 2000
    Maybe it's just me, but I find that roundbacks are more aerodynamic....
  5. rablack


    Mar 9, 2000
    Houston, Texas
    That reminds me, should Xavier G ever build the "bass boat" he designed for the "do upright bassists hate normal bassists" thread, he should choose a roundback otherwise the lack of symmetry will cause it to always pull to one side.
  6. Another generalization is that roundbacks have a more "singing" sound. I don't know, like Ed said, every bass is different. All I can do is relate my own experience.

    When I was searching for a new bass one of my main criteria was that the bass project. Projection may have been higher on the list of priorities than complexity of sound. I wanted a canon. I was lucky enough to find a bass that is a canon and also possesses a beautiful complex sound. That bass happens to be a flatback. I played roundbacks that had sweet complex sounds and projected well, but not as well. Again, that was only my experience with basses I played.

    According the Paul Brun, the reason for the existence of flatback basses is twofold. With the advent of the violin family (in which the modern doublebass belongs) viol-family instruments became obsolete. Many doublebass viols were converted into doublebass violins despite viols having flat backs. It was discovered that the back, whether flat or figured, had little or no effect on the sound of the instrument. As a result of this discovery, not only could doublebass viols be converted without having to have their backs replaced, but new instruments could be made with flat backs, which greatly reduced the cost of building a doublebass violin. The same story also explains the existence of basses with "gamba corners" and "violin corners".

    That flatbacks crack more often is only true for flatbacks whose braces are *not* free-floating. The braces should not extend all the way to the ribs. I believe many modern luthiers also put a small, totally unnoticeable figuring in the back. In other words, they build them to look flat but in fact are not. These two features allow the wood to freely expand and contract with climactic changes without any adverse affect.
  7. This is what ya need to do. Go to Kolstiens shop. Play a round back, then play a Fendt. Tell me its the actual back after you play it because that thing is a BEAST. Man can it project, and boy can it sing. IMO, its the craftmanship of the bass, or the woods used, or the way it was built, or its age, but not much of the flatback or roundback thang.And no matter what type a back it has, DB's will always look better than a violin :smug:
  8. From all the basses I've played, I don't think there really are any characteristics that can be directly linked to either back. I personally like the look of a flat back better, and I like the way it sits when i play seated, too. My only concern would be durability; I've seen a lot more issues with flat backs than round. Whats really starting to freak me out a bit is how much the flat back on my X-braced Shen is sinking in; At the deepest point now it's sunken about an entire inch. I've been told that's pretty normal and it shouldn't be an issue, but it's still disconcerting. It seems like if it's gone that far in six years if it keeps going my bass might just implode in a few years... :eek:
  9. Toman, do you notice seasonal changes with the flatness of the back? It would make sense that it would sink in in dry weather, heating season.

    I have pretty much decided that my next instument that I build will be a flat back-guitar shaped (cornerless) but the back will be domed a little to ward off evil sinking. Plus I am going to laminate the back and sides to make them more stable and allow them to be stiffer. I believe this will add to the volume since the back will absorb less energy resulting in volume.
  10. Contra|Brett|


    Oct 6, 2004
    I have heard that orchestral players who sit while they play like flatbacks a little more (not that it would be more important than the way an instrument sounds) because they balance better when you sit w/ them.
  11. I've never noticed any difference between seasons, but then i don't make a habit of measuring the thing, either. ;) I agree that flat backs are more comfortable to play sitting down; it just rests more nicely.
  12. I've played a round back factory bass [Gotz] since 79' and got my first flat back when I opened my shop years ago.
    From a players view I can say the flatback w. its springy sound and feel seems to project more,and from behind also.I can hear it better from the drivers seat.
    That said I can say from a repairman's view that flatbacks are more troublesome.Here in New England the cats w. flatbacks need to do more soundpost changes.But alot don't ,and so I stay real busy w. the glue pot come January!!
    [By the way, I still love my Gotz!}
    djc03006 likes this.
  13. Sam Sherry

    Sam Sherry Inadvertent Microtonalist Supporting Member

    Sep 26, 2001
    Portland, ME
    Roger that, and thanks for all the help, Mark. Much as I enjoy seeing you I'm hoping to skip our annual get-together this winter.

    It turns out that a large part of the reason I got to commune with Mr. Carlsen so often is that some ****ing clown who is NOT Mr. Carlsen put the back braces on my Czech bass down using a bucket-load of epoxy. Every winter my braces would try move in one direction while the back would move in the other, with the epoxy acting as judge and jury. Fortunately, that is now being corrected. Yucko!

    I grew up hearing and playing flatbacks. I've owned several solid and ply round-backs. They all sounded too diffuse for my mind's ear. But there sure are some nice-sounding ones out there.
  14. jneuman


    Apr 17, 2004
    Based on modal vibration measurements done by some guy as part a research project, flat and round do have very different vibrational patterns on the back at least, as you would expect. Iv'e played both types that sound good, and both types that don't. I would think that one doesn't go out looking for one or the other, but rather that the bass they are looking for has the sound quality they want. Flatbacks are more trouble to maintain obviously. Also, new basses with flatbacks are considerably cheaper than roundback ones due to the savings in carving time and wood cost.


    AMJBASS Supporting Member

    Jan 8, 2002
    Ontario, Canada
    I don't think you can really say that flatbacks are more difficult to maintain. I have had 3 and haven't had any problems to speak of. I also live in a climate where the temperature fluctuates by quite a margine. As long as you keep the humidity level fairly constant, there is no reason why you should have any problems.
  16. arnoldschnitzer

    arnoldschnitzer AES Fine Instruments

    Feb 16, 2002
    New Mexico. USA
    Flatbacks are more difficult to maintain. Wood moves, crossbars HAVE to bust loose or the back cracks. No bass exists in a constant climatic state. That said, many flatbacks are wonderful instruments which will last centuries if well-kept.
  17. John Sprague

    John Sprague Sam Shen's US Distributor

    Mar 10, 2003
    Rochester, NY
    Sales Manager, CSC Products Inc.
    It's the CSC gang's belief that our basses almost universally sound better in flatback versions. "Better" being a subjective thing, of course. Our 7/8 round does fine, but in flat it frightens cellists. :smug:

    Speaking of climatic states Ahnold, it's just about that time for all the crack repairs to come streaming in. Time to check the glue stash.