Official Luthiers Forum!

Is there a general consensus as to whether it is better to have a heavy cast tailpiece or a light weight one? It seems to me that the heavy cast one, would function better as an anchor and absorb less of the string’s energy. Am I thinking about this wrongly? I know Benedetto prefers ebony because of the tone and light weight, which implies that it plays a part in the way the the guitar sounds overall. This might be true, and a dampening of the string’s energy may be the kind of sound that he and many others find desirable in a jazz guitar. What are you thoughts?

I have used the Benedetto style violin tailpiece, a brass skeleton/Ebony topped one similar to Eastman, a CNC’d Aluminum model, and aftermarket bronze (I think) copies of the Gibson L7 tailpiece.

My hearing is far from perfect these days but I really didn’t notice any major difference.

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

Violin makers, and set up guys often try to get the afterlength, the length between the bridge and the tailpiece to be 1/6th the length of the string length. The pitch ends up being two octaves and a fifth above the open string. I guess that they hope that it helps support the notes? Just the open string maybe, but what about the rest of them? I'm not into tradition.

I look at it as a mechanical thing. The entire length from the bridge to the saddle is moving. What are you doing with that? I make mine so that the after length is halve the length of the distance from there to the saddle. I make the tailpiece long enough to make that work. I imagine it like a 2:1 lever that is hinged at each end, and moves where the strings are attached. I even try to get the numbers to make a ratio work on the afterlength too. A short stop on a longer body might get a minor 6th ratio. A long stop on a short body a flat 5th, or maybe even a fourth. Many normal instruments come out right at the fifth.

Does it make any difference? I don't know. But in my head it does. Isn't that what matters? Many guitars, and some violas and cellos have that tailpiece that is angled, the low strings have more overhang. I can see that it could change the string angle some, but enough to worry about? To me it would cancel out any movement that MIGHT have been introduced by the 2:1 ratio, and the strings might not be as lively. That's the only reason I do it; that it MIGHT make it livelier.

My archtop has a 625 scale. The 2:1 gave it about a 75 mm afterlength. If I made the bottom 10 mm or so longer it would be 8:1. Would THAT be better? I don't know that either until I try.

I doubt that material makes any difference. Mine are just wood to match what the other stuff is. I do balance them lengthwise so they rock nice though.

_________________
Why be normal?

The tailpiece does vibrate, and can do so in several ways. The most active vibration mode, and probably the most important, is the one where it pivots at the hinge or tail gut at the lower end with the upper end flapping up and down. This will resonate at a particular frequency depending on the mass and center of moment of the tailpiece (roughly, where the center of gravity is), and the string tension. You can hear this fairly easily in many cases by tapping on the top surface of the tailpiece down toward the guitar top.

This resonance will couple with the top due to the fact that it pulls up and down on the bridge through the after length of the strings. The shorter the after length the more strongly it couples. Normally this won't produce enough sound to be an issue one way or the other, except when the tailpiece resonance is close in pitch to a resonance of the air or top that causes the bridge to move up and down. For the most part this would be at the low 'main air' pitch (anywhere from G on the low E string up to maybe B on the A string), or the 'main top' pitch, an octave or so higher (so, close to the pitch of the open G string). When there is a strong resonance and it couples well the top and the tailpiece will drive each other in a sort of complex dance, and this can produce useful sound.

When I made my first nylon string arch top I was not happy with the bass response. I had made the tailpiece light, and the resonant pitch was quite high. I experimented with adding weight to it using poster adhesive, to get the tailpiece resonance to match the 'main air' mode. When I got the right amount I cut out a piece of lead and stuck it to the tailpiece with double stick tape. I took the guitar to show a friend of mine, who happened to be out of the shop at the time. His shop buddy, who was a good player, started to try it out. As he was playing my friend walked in. After listening for a bit he asked: "What's with the lead on the tail piece?". I reached over and removed it, at which he exclaimed: "Who turned off the speaker!?".

Jim D'Aquisto said in a talk once that he could shape the sound of a completed guitar a lot by working with the tailpiece. Depending on the way it's hinged it can have several degrees of freedom, each with it's own resonant pitch that can, conceivably, couple with the top in some way. If the pitch matches something the guitar wants to do, you can get all sorts of results, some of which can even be good!

So Alan, it sounds like what you are saying, is that it isn’t so much that a heavier tailpiece is necessarily better, it’s that it needs to be the right weight for the “after length” in relation to the string tension. I guess you can only figure that out through experimentation.

That's about it.

Note that string tension is one of the things that determines the tailpiece mode frequencies, so changing strings or gauges can alter the response. Pitch matches generally need to be pretty close to be really effective.