Hello colleages! I'm doing research on basses, and have a few questions concerning flatbacks. 1. Is there a general difference in the sound or playability between flatbacks and roundbacks? 2. Are there particular disadvantages involved with one type or the other? The project may eventually shed some light on the acoustical differences, if any can be found! Thanks, Andrew
Andrew: Nice to hear from you. If you scroll down a few threads under "Basses", you will find a thread entitled "Roundback vs. Flatback". I think that the consensus is that there is no consensus. Ed Fuqua sums it up by saying, "different basses sound different". If you read further, David K ellucidates that particular point. Anyway, if someone could provide some acoustical delination between the two, I would certainly be interested.
As a player, maker and seller of basses I've heard a lot of comments on this subject over the years. The general concensus is that flatback basses have a better sound. However, I know of many, many exceptions to this. The drawback to a flatback bass is that they tend to have more health problems because of the bracing on the back. The spruce and maple contract and expand at different rates and this causes the backs to crack which is a rarity with roundbacks. Some makers have tried to solve this problem using X bracing instead of the 3 or 4 cross braces, and some have used only one brace at the soundpost location. Personally I think the design of the bass and the top have a lot more to do with the sound than the back does. I currently have a very old bass, probably flatback originally, with a plywood back on it and it is positively wonderful.
Thanks for your comments, Martin. Of course, its also hard to define what sounds better, since its largely a matter of taste. There are certain criteria for the musician and for the listener, which are often quite different. I've heard that flatbacks tend to sound 'bassier' and roundbacks 'more focused'. I think it's been established that the top plays the dominant role in the sound production, but there are other aspects of the instrument, like aesthetics, production convenience, playing comfort, or stability, which also are a part of the difference. There are also those out there who remove the original backs of antique instruments and replace them with plywood, which for me is somewhere between unacceptable and criminal, but they swear it sounds better. As a response to Samuel, the pic is good, but I can top it! See http://iwk.mdw.ac.at/ab/octogon.jpg ! Greetings, Andrew