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What's the purpose of a bridge?

Discussion in 'Hardware, Setup & Repair [BG]' started by Garrett Mireles, Nov 9, 2002.


  1. I know it's what keeps the strings in place, but what do you gain by upgrading to, for example, a BadAss II bridge?

    Just fer looks?

    Thanks. :)
     
  2. SuperDuck

    SuperDuck

    Sep 26, 2000
    Wisconsin
    Some debate that a more massive bridge provides longer sustain. Also, some allow more adjustments to be made, like width from string to string. And new shiny bridges are prettier than old rusty ones.
     
  3. rickbass

    rickbass Supporting Member

    One aspect is the "mass" and material composition of the bridge.

    It conveys the harmonics, partials, and sub-harmonics it receives through the body to the pickups.

    For instance, an Andreas "Shark" bass uses an aluminum bridge. The notes come out with lots of "ping" due to the characteristics of aluminum.

    A big, heavy, brass, bridge produces low notes/fundamentals extremely well from the "information" it receives from the body.

    Guitarists don't worry about bridge mass and composition so much as bassists because pickups are more crucial to the sound of a guitar than a bass.

    That's just a simplistic interpretation. The luthier's construction skills and the quality of the woods are crucial factors that require additional discussions.
     
  4. SuperDuck

    SuperDuck

    Sep 26, 2000
    Wisconsin
    The aluminum fretboard can't hurt none neither. (That's right. Triple negative.)
     
  5. Thanks man. I'll look into it once I get my new bass.
     
  6. I always thought most bridges were just an excuse to get back to the chorus again without having to write another verses worth of lyrics, guess i'm wrong. :)
     
  7. I'm of the opinion that bridge design plays a crucial part of the bass timbre. Of the basses I have / had, the more massive the bridge, the bigger the sound/more sustain. Just a better sound in some cases. But you have to think of how the bass as an acoustic system works. It depends on how the strings couple with the nut, neck, bridge, body and then you. You hold the bass, and are actually changing it's acoustic mass if you hold it lightly on your lap, or have it hanging from your shoulder against your body. Plus how much pressure you apply w/ your hands.

    Short answer, it makes a difference. But so do a lot of other things.
     
  8. LA

    LA

    Oct 17, 2001
    Michigan
    I thought the Bada** Bass V made a difference on my MTD Kingston in the areas of sustain and tonal clarity. The chrome knobs I put on it didn't seem to do anything for the sound, however.
     
  9. Adjustable string spacing could also be a reason to upgrade your bridge.
     
  10. jani_bjorklund

    jani_bjorklund

    May 22, 2002
    Finland
    The purpose of the bridge, besides anchoring the strings of course, is as with any stringed instrument to transmit the vibrations of the strings to the body.If that is done successfully you're allready having a "goodass" bridge. A new 100 buck bridge may give you additional features like multiple adjustment possibilities. I have built many basses and used good(expensive) bridges and standard fender type bridges and I would like to say that it's not the iron, it's the wood that makes the tone.
     
  11. I can't let this go by without a little clarification. Solid body instruments do not require string vibration to be transferred to the body as Jani has stated. Theoretically, a stringed, electric instrument could be made without a "body" at all and it would create sounds as well as a conventional instrument. Acoustic instruments, on the other hand, DO require this transfer of energy because the only way the instrument is to make a sound is by vibrating it's components to an audible level. By using high mass bridges, you are isolating this transfer of energy to the body which explains the usual reports of increased sustain. Just what you would expect if more of the strings vibrating energy is retained by keeping it confined to the string and not allowing the body to absorb the energy. Understand that I am NOT saying that the materials or construction of a solidbody instrument have no bearing on it's sound. They do, but that influence is only realized through the electrical signals created by the strings. Acoustic vibrations don't affect pickups in the same way they affect a nice Sitka spruce top on an acoustic guitar. Different body woods and construction can emphasize or de-emphasize certain harmonic components of an instrument's sound but all of this is translated back through the strings and not the body of the instrument itself.

    I use and endorse high mass bridges because I like the additional sustain and clarity they offer. My Kawai has one of the largest (heaviest) brass bridges ever offered on a 4 string and, combined with the rather hard and heavy woods of maple and zebrawood in it's construction, it has an amazing piano-like tone, sustain, and clarity. All of this is due to keeping those strings vibrating and not allowing the smaller, higher pitched, lower energy harmonics from being lost through their transfer to a soft body wood.
     
  12. jani_bjorklund

    jani_bjorklund

    May 22, 2002
    Finland

    I don't know if this is pure ignorance or somekind of "new age" doctrin or what. "The solid body instrument do not require string vibration to be transfered to the body" . What a statement! I know Leo and many others with him are turning in their graves. Of course a solid body need to have the sound transfered to the body and to the neck as well! The wood in the body and the neck are essential to the sound. If not, you could use a piece of rail and attach strings to it. Real musicians don't look for "infinite" sustain using bridges weighting a pound, graphite necks, weights on the headstock, glass freatboards and gimmicks like that. Real musicians look for the wood tone of an instrument. If a guitar don't sound good without an amp, it's a useless guitar. It's all in the wood. Please don't broadcast such a missconception!
    Go and ask any luthier to get this thing steigthened out.
     
  13. pkr2

    pkr2

    Apr 28, 2000
    coastal N.C.
    Actually, Hambone is 100% correct with the statement that he made.

    No wood or bridge coupling is required to produce sound on a solid body instrument. ONLY ELECTROMAGNETIC coupling is required.

    And yes, you can mount the pups on a rail, suspend them in mid-air or float them on water and as long as you have magnetic coupling they will produce sound perfectly well.

    Thank you for informing us as to how a "REAL" musician does things.

    As far as asking a luthier to get this "steigthened" out, there is nothing to straighten out... You're wrong!

    Pkr2
     
  14. rickbass

    rickbass Supporting Member

    I agree with you, jani, and then, I don't. An electric bass, a WELL BUILT electric bass is dependent on the body wood/woods and neck for tone.

    But the bridge, as very knowledgeable people, like Hambone and pk2r point out, is essential to vibrational transference and the sonic outcome of the instrument.
    The Andreas Shark and its aluminum bridge is a good example. It "rings" the high tones because it is made of aluminum.

    IME, those factors you cite as "gimmicks" aren't "gimmicks." They really do affect the final outcome as long as you have the electronics and amp to accurately portray them.
     
  15. Wow, Jani :rolleyes:

    I truly thought that using terms in my response like "theoretically" and statements like "Understand that I am NOT saying that the materials or construction of a solidbody instrument have no bearing on it's sound" made it perfectly clear that I understand the physics of instrument construction. I only wanted to address your outright statement that said all stringed instruments require the string vibrations be transferred to the body in order to make sound. That concept is patently false.

    Let's look at some anecdotal examples of just how this isn't true. First, by your statement, the new breed of "skeletal" electric violins shouldn't work well or be chosen by "real" musicians because they don't rely on the tonal characteristics of wooden construction to sound proper to the owner. If you've got the stones, perhaps you should explain that to "real" musicians like Jean Luc Ponty, Papa John Creach, or Noel Pointer (I think) because they sure do like 'em. And maybe those darn acrylic Dan Armstrongs, Turners, and the other "see through" instruments are just high tech eye candy and never meant to be played by "real" musicians because they aren't wood. Or maybe you can explain how those neat electric upright basses make any sound at all since they have very little wood in their construction compared to an acoustic upright. If you CAN explain this, I'm sure that "real" musicians like the bassist for Spyro Gyra (I can never remember his name) and our own Gard would be interested so that they don't have to waste their time anymore. And lastly, I'm sure the guys over at G-Bass would be astounded to learn that their basses don't sound good at all since they have little or no wood and no traditional bodies included in their creations.

    My original post, if you had read it ALL, made it clear that tone is definitely affected by the entire construction of the instrument. But my point wasn't about tone. It was about sound. And the sound from a solid body instrument, pleasing to you or not, is totally independent of any material or construction and certainly the bridge design itself.

    Your passion for your craft is admirable, but don't let it ever crowd out logical, clear, thought. Understanding these basics makes learning the more complex stuff easier.
     
  16. Great thread !
    I'm very gratefull for the fact that Hambone couldn't let it go by ...
    Your clarification made a lot of sense and made things a lot clearer.
    The following comments cleared things up even more ...
    Thanks guys, especially Hambone.

    Just to see if I really get it ...
    So the tone of a bridge (or body or neck) is basically determined by how it affects the vibration of the string, right ?
     
  17. Hi guys.
    The little I know about sound ,I say that the tone (what makes different a C on a piano from the same note played on a bass), is the modulation of the frequencies (harmonics) that you make vibrate when you hit the string (right?).
    And I believe that the entire instrument will help to boost up some of the frequences and hide away some of then ,affecting the tone drastically.
    I would say too that a body capable of getting resonance with the frequency you play will increase your sustain a lot more.

    Ps.:sorry bout the bad english
     
  18. jani_bjorklund

    jani_bjorklund

    May 22, 2002
    Finland
    It's ridiculous to state that the purpouse of the bridge is to "isolate" the strings from the body. What a mess. On the contrary, the purpose of the bridge is to couple to the body, and the better this coupling is the better the bass is sounding.
    And I think I know my electrophysics. I know how a pickup works and how it's made. That's not the point. We were debating the purpouse of the bridge. Of course everybody knows there's no bridge / wood coupling needed to produce a sound with an electric bass. Each and every kid knows that much. You can even suspend a set of strings anywhere(and that's been done various times), like "pkr2" says, but that's no bass, only an experiment in electrophysics. If you are looking for a good basstone you absolutely need the bridge / wood coupling, and not to "isolate" the vibrating strings from the body. How on earth could the wood , as Hambone oddly admitts, affect the tone if there were no acoustic coupling and the vibrations were "isolated" from the body??
    Remember we were NOT discussing how the sound is produced on a electric bass. The discussion was all about the purpose of the bridge.
     
  19. Hambone has NOT stated that the purpose of a bridge is to isolate the strings from the body, but to isolate energy transfer to the body, in other words : keeping the strings vibrating instead of the wood absorbing the vibrations. (big difference)
    It makes sense when you think about it, an upright with a wooden bridge hasn't got much sustain, has it ?

    As for as how the wood could effect the tone, the wood is what connects both ends of the strings, so surely that must have an influence on how the string vibrates, and thus influence the tone.

    The discussion may not be about how sound is produced on a bass, but it did help me understand the function of the bridge better.
     
  20. jani_bjorklund

    jani_bjorklund

    May 22, 2002
    Finland
    I would also like to give bassplayers more references concerning the issue in this thread!

    http://www.jetguitars.com/treatise.html

    "BRIDGE. The bridge, nut, tuners and tailpiece all determine string coupling. Above, I mentioned "how directly coupled a string is to a guitar"... An acoustic engineer could break this out in a lot more detail, but let me just say that, this is more than simply a matter of how large the contact area is, or what metal alloys are in the parts. Generally more mass and body contact = more coupling. This was the idea behind brass bridge plates and nuts in the 70's. However, there is more to it than that. The bridging and anchoring points of the strings all interact together to transmit vibrations between the guitar and the string, giving feedback. As this feedback happens, certain frequencies are reinforced and others are cancelled. How efficiently this transmission and feedback happens is coupling. Coupling can also be more pronounced in different parts of an instrument's harmonic response. A steel tremolo bridge, for example, seems to be good at transmitting higher harmonics, and not so good at transmitting lower ones. A brass hardtail or steel tune-o-matic better transmits lower harmonics and fundamentals. Stringing through the body may give longer sustain, and a more acute angle over the bridge gives sharper attack."

    http://www.lpdmusic.com/Italia/new models/maranellobass.html

    "BASS
    Sparkle, Pearl and a floating control plate, Stop tail/bridge combination, and two Humbuckers. We threw everything we had at this, and it all stuck. Check one out to find that under the extrovert exterior is an equally competent bass to compete with the best of them. Unique tonal spectrum from the harmonically positioned pick-ups. Fantastic string to body coupling from the massive bridge assembly."

    and also
    http://www.usmasters.com/features.htm

    if this is not enough type: "string and body coupling" in Google and you'll have a lecture for the rest of the day!