Weight and Sound

Discussion in 'Setup & Repair [DB]' started by Martin Sheridan, Dec 25, 2003.

  1. Martin Sheridan

    Martin Sheridan

    Jan 4, 2001
    Fort Madison, Iowa
    Bass Maker
    Those who have seen other posts will note that Bob Branstetter and I don't always agree on weight and sound.
    Years ago I was absolutely convinced as Bob is that weight kills sound. The reason I don't necessarily share this opinion anymore is two fold. First, I've played too many basses that I could hardly lift that have had fantastic sound quality and volumne. Secondly, we are putting on brass low C and B extensions at KC Strings that absolutely open the basses up. A few weeks ago, Anton finished two new basses. One I loved, the other I thought was good, but not as good. A few days later they put on an extension on this bass and walla it was both louder and had an overall bassier sound. I haven't worked with the AO-BO principle that Bob talks about. On my own basses I tend to put in smaller bars and I don't like too much weight, but as far as the relation to sound is concerned I don't think weight by itself is the deciding factor.
    Bob, your turn.
  2. Martin - I have no intention of getting into another discussion of this with you. I have asked you repeatedly in the to give one example where adding weight has improved the sound of any member of the violin family. I don't want to hear another of your sales pitches about how your employers heavy brass extentions have done wonderful things and how every customer you've had raves to high heaven. Give an example where the people here can try it for themselves and get REPEATABLE results. You say you don't know anything about the A0/B0 matching even though I've sent copies of my MVA Journal paper to your boss Anton. If he doesn't have it, let me know and I'll send you a copy. When you've taken the time to read about and try matching B0 to A0, I'll be happy to discuss it with you = otherwise forget it!
  3. Before you two cool off or become disinterested in this...I'd like to know what AO/BO matching is. Please don't send me to search through the Archives for it. Just a quick explanation would work for me. Thanks!!
    My interest in this is personal, because as Bob knows, my Bohmann fiver has these fantastic machines that are probably the heaviest machines in the bass world (cast iron and brass) Also, the neck and scroll are carved out of two pieces of ebony sandwiched between three pieces of curly maple! The best quality ebony finger board designed to handle five strings. On and on...you can see on The TalkBasses under DB/Basses.
    The bass is not the loudest i've ever heard, but makes up in personality and eveness.
    Anyway, all the weight doesn't seem to have an impact on the sound...it does have an impact on my body trying to carry it around!
  4. arnoldschnitzer

    arnoldschnitzer AES Fine Instruments

    Feb 16, 2002
    Brewster, NY, USA
    The best weight for a bowed instrument is the least which allows it to play and survive without imploding. Heavy basses sometimes sound great DESPITE their mass, not because of it. I agree with Bob B. that attributing an increase in bass response to adding a mass of heavy brass to the scroll is rediculous. This said, often a C-extension will open up the bottom end of a bass. After all, you've now got about a 52" string length on that bottom string! Anecdotally, I've removed many heavy extension machines and the players have nearly always experienced a tonal improvement. Bob, please send me your AO/BO paper, as I like reading anything I can get my eyes on about instrument making and adjusting. (No, this does not mean I'm sold on the idea--just curious.)
  5. Martin Sheridan

    Martin Sheridan

    Jan 4, 2001
    Fort Madison, Iowa
    Bass Maker
    Thanks Paul for er "weighing" in on the issue.
    Bob, send my a copy of your research, I'll be glad to read it. I didn't mean to get you so upset, but I noticed that you brought this up on another post again.
    All of the so called scientific research eventually comes down to subjective judgment. Sooner or later players play the instrument and give their opinion.
    Many of the German basses starting in the 60s have too much wood in the tops and the bass bars are too big; there is too much weight in the wrong place. However, most of the great basses I've heard have been very heavy basses. Perhaps that's because of their size? Most of them had rather narrow and small necks and fingerboards that because of planing were thinner than what we start with. I'm sure that this could effect tone.
    Ted Moniak, a former apprentice of mine, studied with Carleen Hutchins. Recently in testing a bass back that he was making he told Carleen that it was way off when he tested it. The Chaldni patterns were good, but the tap tones fell almost an octave too low(the wood was willow). When he told Carleen this she said, "you know Ted, sometimes it just doesn't work". There have also been tests done on a few great Strads and they were found to test differently that modern scientific practice would have assumed. The tops by the way were surprisingly light, some weighing only 55-58 grams.
    Charles Traeger once told me that if you wanted to see how weight will kill sound, put a C-clamp on the scroll of the bass. Several of us did this to every bass in the shop and were frankly amazed that we couldn't hear a difference. We expected that the volumne of sound would drop off dramatically, but no one thought that it did, except on one bass.
    On my own basses that I make, I like to try to keep them on the light side, and I'm thinking about going willow for the back and sides for this reason. Also, as Paul points out, it makes them a lot more agreeable to haul around.
    My teacher, George Cass, had a very light bass and I became convinced that that was why it sounded so much better than mine. Then one day he demonstrated on my bass and I was amazed to find that the fault was not in my bass, because George made it sound as good or better than his.
    So, Bob, how do you demonstrate and prove that what you are doing works everytime? Is it by looking at what the electronic equipment is saying, or by what you are hearing. If it's by hearing how is that any different from our experience with the brass extensions? And have you ever done these tests on a bass where the test results were not good, but the bass sounded good?
  6. OK guys I will send copies to all you, but let's get back to the subject at hand. I have said Absolutely nothing about how the weight of a bass has anything to do with how it sounds. There are a lot of factors that go beyond weight alone.
    what I have said repeatedly is that ADDING additional weight kills sound. I'm not talking about bass bars even though we all know that too heavy a bar is not good. I'm not talking about making the plate graduation 2 inches thick or any such thing. I would like to think that maker knows something about how to make a bass. I'm talking about ADDING mass in the form of very heavy machines, extensions and fingerboards AFTER the instrument is made.

    A0/B0 matching is nothing new to violin makers. They've been doing it for centuries. Any decent violin maker knows that the mass of the neck and the mass of the fingerboard affect the total sound of the intrument. He's taught or has learned by experience how to get the external parts of the instrument to vibrating in sync with the body's natural resonance. A0/B0 matching simply uses mechanical devices to accurately determine the resonance frequency of the body (A0) which is for all practical purposes fixed with the resonance frequency of the neck assemble (including the neck, scroll, fingerboard and the tuning devices). Once you know that, it is possible to accurately match the two parts so that they vibrate in sync. What do you gain by doing this? The most noticable difference is in the vibrations you feel through the neck while you are playing. That tactile feel has a lot to do with intonation.

    Martin - if the guys in your shop could not hear any difference when a heavy C clamp was attached to the scroll of any bass, then I can understand why you think adding a ton of brass improves the sound. You've ALL got to be deaf. And... do you ever process anything I've said about Carleen Huthins? Chaldni patterns have ABSOLUTELY NOTHING to do with A0/B0. We are not discussing plate tuning here AND NEVER HAVE BEEN!!! I have no idea what bass "Test Results" you are talking about. Be specific for a change. The reason people do scientific testing is to elimate variables (like your teacher playing better than you) so that the testing is done under identical conditions. Thank God you don't work for NASA.
  7. <--- *sits back, grabs popcorn and beer*

    Interesting stuff guys. Thanks.
  8. Jeff Bollbach

    Jeff Bollbach Jeff Bollbach Luthier, Inc.

    Dec 12, 2001
    freeport, ny
    I'm not sure these guys need encouragement. But then again, with Ed gone things have been a lot more bland in these parts. God, I miss that guy.
  9. When it comes to this subject, you are absolutely right. No encouragement needed.
  10. mpm


    May 10, 2001
    Los Angeles
    tick, tick, tick...(as he pops a "Bud")...
  11. Martin Sheridan

    Martin Sheridan

    Jan 4, 2001
    Fort Madison, Iowa
    Bass Maker
    The C clamp experiment was at a different shop.
    Thanks for sending the AO/BO paper, will read it today.
  12. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    Wow, a flame war between luthiers. With all that antique wood lying around, this could get interesting.

    I've read the A0 B0 paper, although I can't say I understood most of it. What I do know is that, in my very limited experience, I like the tone of some heavy basses very much for pizz. Other than that, I'll just share the beer/popcorn vibe and lurk.
  13. Martin Sheridan

    Martin Sheridan

    Jan 4, 2001
    Fort Madison, Iowa
    Bass Maker
    You should post your paper here for all to read.
    I particularly liked your adding lead weight to the underside of the fingerboard, and the feather at the f-hole was pretty ingenious.
    In the end you said exactly what I've been saying all along which is that after all this measuring YOU decided by playing and listening that the improvements were in fact there. That's subjective and not objective. What happens the next time the player has to have the fingerboard planed? Did you check to see if the AO changed if you moved the post, or the bridge, or the string distance to the tailpiece?
    Finally, did you test all the basses that have come into your shop? Did any of them sound good where the AO?BO didn't match?
    Looks to me like neither of us should work for NASA. Anyway, looks like your having fun. Good luck.
  14. Martin, by your definition, Everything is subjective! The laws of physics are subjective to you. If NASA finds there is a leak in the O rings by testing, then I guess it is subjective that the rocket happens to blow up.

    Adding weight to the underside of the FB was not my idea. Another CAS member figured that out long before I got into it. The feather at the f-hole was the brainchild of David Wilson, one of the owners of Hammond Ashley Associates. David Wilson was responsible for getting me interested in A0/B0 matching in the first place. I simply took what he taught me and combined it with what I learned while attending a MVA/Catgut Acoustical Society joint meeting in 1996. The Radio Shack meter - "the mode sniffer" - came from a presentation at that meeting. Nothing I'm doing is really original by me. Violin makers have been using it on violins, violas and cellos for years before I found out about it. I simply adapted the process to the double bass.

    You need to re-read the paper concerning A0. There is nothing that you can do (without disassembling) to the instrument that will change the Resonance frequency of the body (A0). That is determined by the volume of Air contained inside the body and to a smaller extent the surface area of the ff holes. Moving the soundpost or tailpiece will make no change to A0 what-so-ever. Neither will planing the fingerboard. However, planing the fingerboard WILL change the B0. Ofcourse you knew that since that is the area where the tuning (matching) is done. Moving the soundpost or adjusting the tailpiece length also has No effect on the B0. B0 is by definition the resonance frequency of the neck assembly.

    Let me answer your question about "Did any of them sound good where the AO?BO didn't match?". Now that is a subjective question. If the A0 and B0 match, then there is no need to change anything. Every instrument that has been matched was improved. I'm not going to use the word sound here since frequently what is most noticable change is the vibration being felt through the left hand. Have you ever play a really good bass that you couldn't feel the vibrations in your left hand? They either exist (sensed by your tactile receptors) or they don't. Can a yes or no, or a all or nothing situation be considered subjective? I try to test any bass than comes in my shop provided I have the time. The really good sounding ones are almost always have the A0 & B0 close the matching. To paraphrase Arnold, some basses sound good DESPITE not being matched.
    HOWEVER, I honestly believe that even the good sounding ones can be improved to some degree by matching those two modes.

    A0 and B0 have to match for the maximum energy (i.e. sound) to be produced. The closer they are to matching, the less the intensitiy of the change. Throw a 2 or 3 pound C clamp or other heavy brass metal object in the mix and the change after matching could be dramatic. As I suggested to you boss Anton a few months ago, before you make a judgement try it for yourself. Everything you need to know about the process in the that paper.

    BTW - I think if I were a few years younger, I think would do quite well at NASA. Basses are not my only interest.
  15. Martin Sheridan

    Martin Sheridan

    Jan 4, 2001
    Fort Madison, Iowa
    Bass Maker
    I have to confess that my evil twin sometimes gets the better of me.Actually I do think that weight kills sound. It's a really hard idea to get rid of because there are a lot of reasons to believe so. The trouble is that I keep running into basses that are very heavy that sound good, and the brass C extensions seem to help. So I can keep believing that weight kills sound, or I can conclude that sometimes it doesn't. Arnold may be right about the C extensions helping because the string length is longer. Although in Dave Anderson's case we took off a wood C extension and put on the brass and he insisted that the bass (a Prescott) had really opened up.
    It might also be that the heavy basses sound good in spite of and not because of the weight, I don't know.
    I also have no trouble with someone employing the scientific method to study musical instruments.
    The trouble is that most of this "science" has more to do with voodoo than it does science.
    The laws of physics are just that. They are predictable and will happen the same way everytime. They can be measured and observed.You may be able to accurately measure AO/BO and match it, but within the equation you have to test it and subjectively decide, and I think that when you are expecting an improvement you are likely to find it. Bob, I don't know if there's a perfect way, but I think you need something like a double blind study where someone else plays the instruments and they don't know and the tester doesn't know what's been done? Otherwise I don't see how your results are any more unbiased than ours? It seems to me that it's unscientific to conclude that the addition of a brass C extension can't help when you haven't heard the basses, talked with the players, or done any kind of testing. I wouldn't have believed it myself because I've always thought that too much weight killed sound, but when player after player voluntarily reports that their bass has opened up, then I think it's something we should pay attention to and not let our bias get the best of us.
    I was hoping to hear from more players about their own experience with theirs or other basses. How about it?
  16. Damon Rondeau

    Damon Rondeau Journeyman Clam Artist Supporting Member

    Nov 19, 2002
    Winnipeg, baby
    Why do you guys keep talking about NASA and science? Those folks are engineers first, scientists second. Witness the incredibly lousy management decisions they make all the time...

    This whole "sound is subjective" thing is a big, messy topic from a scientific method point of view. I would suggest that it's a lot more similar to research about pain and pain perception than it is to anything involving physics.

    Bob and the Catgut crew are working with the physics. The physics are straightforward and mathematically precise, but they are only a starting point. How do you harness *anything* having to do with A0/B0 matching to the goal of reliably producing excellent-sounding instruments every time?

    The problem is in the subjectivity of a) perceiving sound and b) talking about sound. If you *really* wanted to get into HARD science (as in science that's not easy to do, not science that is comfortably "objective") then go beyond this physics starting point and start dealing with psycho-acoustics.

    That's where the similarity to pain research comes in to the picture. No one can get inside someone's head and observe their pain. You have to ask them "how much does it hurt?" and you have to work with the responses. No one says, "ahhh, pain is totally subjective, there's no science there." Actually, our BEST scientists are working on hard projects like that. You do it over a long period of time, working very carefully with language, and you make full use of statistical/probabilistic approaches as well as experimental approaches.

    If you threw enough time and money at this problem you'd learn TONS about how to build to the criterion of peoples' ears and what they like. Nobody's got enough time and money for that, however. It's going into things like pain research, and that's the way it should be!
  17. I have to confess that my evil twin sometimes gets the better of me. Actually I do think that weight kills sound.

    Please kill your evil twin! Quickly!

    It might also be that the heavy basses sound good in spite of and not because of the weight, I don't know.

    Well, that's a start.

    It seems to me that it's unscientific to conclude that the addition of a brass C extension can't help when you haven't heard the basses, talked with the players, or done any kind of testing.

    What kind of INDEPENDENT Tests do you have in mind? We all know that the human ear has no memory. Can you remove and reinstall the brass extension in a couple of minutes before the ear forgets? That would be the only way the human ear could be used. In a double blind test you can only have people decide which of a group is the best. Unless you could remove the extension and then install it again within minutes, that kind of a test is impossible. On the contrary, electronic instruments can measure and record the output energy and the physical movement of the instrument so that results can be compared at a later time. You can't use recording to compare sound because of the inaccuracy of the speakers and the room they are placed. Has anyone ever noticed that violin/bass shops are usually pretty bare of sound absorbing chairs, rugs, sound proofing drapes and ceiling tile? There's a good reason for that. The seller want to have the instruments be as loud as possible with lots of sound reflecting surfaces. Physics at work. I have to wonder if there were any sound absorbing materials in the room where the players tried their basses after getting the extension installed. I would wager that the players had not played in that room prior to having the work done . There is another possible reason for the players thinking the bass sounded better.

    I wouldn't have believed it myself because I've always thought that too much weight killed sound, but when player after player voluntarily reports that their bass has opened up, then I think it's something we should pay attention to and not let our bias get the best of us.

    I have deliberately not mentioned the opinions of my customers who all beleive A0/B0 has improved the sound and FEEL of their basses. That proves nothing. I've seen enough of your sales pitches about brass improving sound to last a lifetime.

    I was hoping to hear from more players about their own experience with theirs or other basses. How about it?

    Well then, why did you address it to me?

    Finally - I notice that Martin has once again avoided giving any examples where the addition of weight helps the sound of any instrument other than the claims about the brass extension. Is the extension a unique product in the world? Nothing else on the face of the earth improves the sound but this product does?

    Damon - are your opinions on the work of CAS based on being a participating member of CAS or an outside observer?
  18. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    How does the thickness of a bass' top enter into all of this? I'm willing to buy the idea that, IN GENERAL, lighter basses will be louder than heavier ones, and most likely better for arco playing. But for pizz playing, I've not cared for many of the extremely light basses I've played, including my teacher's $80K Italian, which sounds like complete a$$ for pizz even by his own admission. I've also read several discussions here and elsewhere which describe the different types of tonal qualities inherent in tops of different thicknesses. How do these things factor in?
  19. It doesn't - we're talking about adding additional weight after the bass is made here. However to answer your question - the thickness, in terms of graduating the plates, is a function of the density and stiffness of the wood being used. Every tree is different. The maker has to take all these other factors into consideration when he graduates the plates. It doesn't make any difference weather you use tap tones or Chaldni patterns or voodoo, the end result is, or should be the same. Also, the graduation of the top is not an independent proceedure. The density and stiffness of the back have to be taken into consideration.

    I don't know anyone who starts out making a bass with the idea that it will be a "pizz bass" or an "arco bass". It just happens that way sometimes depending on that particular piece of wood.
  20. so if you add weight to fix the ao/bo it doesn't kill sound? so adding weight doesn't kill sound? but if you just add weight it kills sound? what if the 3 pound c-clamp is just the right amount to correct the ao/bo?

    if you don't subscribe to the CAS you can't bring it up? internet free.. CAS, not free. this is the internet. anyone with a business is spamming no?

    so conservative dude, serious question, one more time, why not an actual publication on set-up and repair of the big double upright thingy that we can't even agree on what to call it? maybe violin rules really don't apply to the big dumb thing. if they did, wouldn't the soundpost be about 3 inches in diameter?

    although i do not miss the cocky bastard, ed fu2, i think one of his most important lessons about the INTERNET was *if you would like to hang yourself, here's some rope* (i mean ME here, not Bob)