New Bridges!

Four bridgesRecently I’ve been experimenting with new bridge designs and listening to the resulting changes in the tone they made on my banjo. I made four very different designs and one standard shaped three footed bridge to compare with.  The results have been quite pleasing and a little surprising.

Bridge Design DiagramsMy point was not just to come up with something that looked interesting and see how it sounded.  I stayed with my theory of having more even string response by either not having no direct path through the wood from the string to the head or having an equal number of paths for each string. All of the above designs met those criteria differently, as did my original violin style bridge. The standard three footed design has an arch under 2 strings and feet under 3 of them, however it is interesting to note that a shorter version of this design will end up with one path for each string over a foot and no path for the strings over arches, whereas a taller bridge of this design will end up with two paths for the strings over the arches. Either way will end up with an uneven response among the strings.

 All of the bridges tested are 3/4″, as I had found that the 5/8 I had been using left me with very low action, and although there were no buzzing issues from it, the playability was noticeably better once I upped it to 3/4″.  [This was done mostly on the advice of Béla Fleck, whom I had on opportunity to meet and show my banjo to recently.  He loved what I was doing with a lot of the design improvements I had made, but also had some setup suggestions.  The bridge height was chief among them.  He uses an astounding 1″ bridge on his banjo. This is not to everyone’s tastes, of course, but I did find that going up to 3/4″ made a noticeable improvement in tone].  The weight of the bridges were all exactly 2.0 gram except for the bottom right in the photo, which weighed in at 1.7 grams. Having mostly the same weight helps by having one less variable involved in the experiment, but was completely unintentional.

Here is what I found after testing each bridge on the same banjo (the “prototype” on this site). I’ll number these according to the drawing diagram, with 1 being on top.

  1. The top left design in the photo (2.0 grams) has three feet and no direct path to the head for any string.  It had a very bright and open sound and even string response.
  2. The bottom right design (1.7 grams) has 6 feet and 2 paths to the head for each string.  It had an incredibly bright, crisp sound, even more so than number 1 and 3.  It was loud, open and even.
  3. The bottom left design (2.0 grams), which I had great fun adding a bit of chip-carving to, has seven feet and 2 paths to the head for each string.  One of the biggest surprises of this test was that this bridge and #1 sounded all but identical.  This also had very even response and a very bright, open sound.  The designs are so radically different, that I am not quite sure how that happened, but it did.  I am curious to see if that holds true on other banjos, a test that will have to be for another time.
  4. The top right design in the photo (2.0 grams) has four feet and no direct path to the head.  It had probably the most even string response of those tested.  Its brightness fell in-between that of the standard design and top left design.  
  5. The standard bridge (2.0 grams), as expected, had an uneven response. It was heavy on the bass response with a muted tone on the treble strings. 

Which was my favorite?  I am very pleased with numbers 1, 2, and 3, as they all really helped to open up the sound of the banjo.  Number 2 is quite possible the best of the bunch and I think would be great in performance as it really has a bright and piercing punch, but for playing at home it is just a bit much after a while, so I prefer numbers 1 and 3 – still very clean and open, but just not quite as piercing.  Some people prefer a darker or more bass rich sound and numbers 4 and 5 would be great for them.  Another test for another day would be just doing variations on the standard bridge to see how the sound changes as it goes from a lower to a higher bridge and to see if I can come up with one in-between, maybe slightly asymmetrical, that would allow one path for each string.  

These bridges are all available for sale if anyone is interested.  Contact me for more information!