tailpiece design experiment

[thistle3585]

I talked with a violinmaker and some sort of acoustician(?) about mandolin tailpieces. I have been working on a wood floating tailpiece design. They talked about how they felt that it was important to be able to tune the strings between the bridge and tailpiece to increase sustain and resonance. The violinmaker said that he did this by using an equation, which I didn't follow, but that gave him the proper distance for each string between the bridge and tailpiece. The acoustician pretty much just agreed. They both felt that stamped or cast tailpieces weren't designed to take this into consideration and they encouraged me to try making a tailpiece with adjustable string posts. I am curious if anyone else has done anything like this. Am I wasting my time? Any thoughts?

[siren_20]

Can you tell us what the formula was?

[steve in tampa]

Makes me think of the fine tuners on some violins, and the Weber Nymph, grommets, and the locking topnut/tailpiece on electric guitars w/ whammy bars.

You might be on to something!

Considered doing it in brass or some other metal? An Allen type tailpiece w/ fine tuners would be cool! I'd try one if it weren't to expensive.

[sunburst]

The distance on a violin (called the swing length) is 1/6 the length of the vibrating string.
On a violin that's one sixth of 330mm, or 55mm.
If you try to apply that to mandolin, it's 1/6 of 13 7/8 inches, or about 2.3 inches.

That could cause some damping, and apparently does on the violin with good results.

I thought about it when designing my tailpiece and decided it wasn't practical because I didn't want to make a tailpiece that big and heavy.

[thistle3585]

No, I don't know the formula but he drew a "kite" then drew the violin on the kite to show what measurements he was using to arrive at his final dimension. #To be honest it was a blur.
Sunburst is right because one of the measurements that he rattled off was that his tailpiece was set at 52 mm. #I didn't understand the formula, but that is the number he arrived at, so I suspect that is where he sets his then tunes it.
Knowing nothing about the physics of it, could you double that number and tune it to another octave, or does that have nothing to do with it? #I assume it has to fall within a frequency or wave or something like that. #Where's Dave Cohen when you need him?

[austin]

I hope I am not too off base with what you are asking, but here's my $.02.
One thing to consider is that most vioin builders agree that even fine tuners negatively affect tone due to their added weight and indirect contact with the tailpiece. Any mechanically adjustable tailpiece could feasibly add a fair amount of weight. You might be better off using the same tailpiece adjuster (this is different than a fine tuner) as a violin.

[Flowerpot]

I had heard that the tailpiece of violins and other similar instruments were designed such that the string length from the tailpiece to the bridge is some even submultiple of the normal string length of the instrument. Like the strings behind the bridge would be 1/8 the distance from the nut to the bridge. That way, the resonant notes of the strings behind the tailpiece would fall on octaves of the open strings. I think archtop guitars tailpieces are designed under that principal too.

Don't know if that is so important on the mandolin, as nearly everybody uses some kind of damper anyway, but it would be interesting to try a tailpiece that worked that way.

[Chris Baird]

It is preferable IMO to have the strings behind the bridge be unresponsive to sympathetic vibrations. It is quite annoying hearing them in between every chop. I have been interested as well in the floating tailpiece design and how it would sound. They work on violins because they introduce a favorable dampening effect. I don't know if it would be favorable on a plucked string instrument which is lacking in sustain to begin with. But, if Monteleone did it and Benedetto did it I guess its worth a try. Let us all know how it turns out.

[EastmanGordon]

I once asked a famous violin maker (who also made mandos) about this very thing and he smiled and said the reason you don't do it on a mando can be summed up by the word "pizzicato". If you want your mando to sound just like a violin does when you pluck it then you set it up like a violin. He went on to explain that a violin is a "cyclical" instrument that is set in motion by the action of the bow and a mando is for all intents and purposes a percussion instrument and the mechanics are quite different. He then started talking in a language that I didn't understand that bore a remarkable resemblance to the language that my physics teacher in college used to use that always ended up with me getting a headache so I ran away.
Hope this helps,
Gordon

[EastmanGordon]

We also tried the Benedetto style tailpiece on our archtop guitars when we first began to build them and discovered that the violin style sacconi tailgut and tailpiece reduced the acoustic sound by about 30% over a metal trapeze tailpiece. I once talked with Bob about that and he said that he wasn't necessarily looking for that bright acoustic sound on his guitars and the fact that the tailpiece damped the sound and made it darker was definitely a plus in a jazz guitar. The ratios in Bob's tailpieces bear no relationship to the equation used in a violin or cello and were done entirely for aesthetic reasons. We offered the sacconi style tailpieces as an after market upgrade on the guitars for a while and as far as I know everyone that did the conversion ultimately went back to the metal tailpiece to get that rich archtop sound back. We now fit all the guitars with a metal tailpiece that has an ebony cover on it that looks for all the world like a wooden tailpiece but retains the acoustic qualities of a metal TP. The best of both worlds. Perhaps this could be adapted for a mandolin?
Gordon

[Keith Newell]

I also build tailpieces and condidered many styles, materials and applications. I expiremented with a violin style tailpiece and noticed the drastic drop in volume and clear sustained tone. I feel my design gives the most in asthetics, sustain, tone and ease of string change, but of coarse I'm biased.
Keith
http://www.newellmandolins.com

[sunburst]

I feel my design gives the most in asthetics, sustain, tone and ease of string change, but of coarse I'm biased.
I feel the same way about mine, of coarse. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[labraid]

A question... We don't play our mandos in just open strings, so as soon as you fret it wouldn't something change in the magical measurement of bridge-tailpiece string octave whichimikallit? If, however, "the equation" gives the same exact number for each fretted length, taking into account the #/17.8171537451651... then it could be quite credible. Otherwise I'd be quite wary..

[Dave Wendler]

Check out the tailpiece on the 5 stringer...this was done to be able to adjust the "resonance" of the strings behind the bridge. The brass rods can be adjusted to "tune" the string length.

Customer seems to be happy with the arrangement.

http://www.electrocoustic.com/newimage/mandos34smallloz.jpg

[labraid]

I forgot to pose my question as more of a question, is the tuning of the bridge-tailpiece length of string taking into consideration all fretted positions as well?

[Flowerpot]

"A question... We don't play our mandos in just open strings, so as soon as you fret it wouldn't something change in the magical measurement of bridge-tailpiece string octave whichimikallit? If, however, "the equation" gives the same exact number for each fretted length, taking into account the #/17.8171537451651... then it could be quite credible. Otherwise I'd be quite wary.."

OK, I'll give this a shot. If somebody is playing the violin, playing a note of the E string, the other strings are open and able to resonate. So if you play, for instance, a D note on the E string, the octave harmonics of the open D string start ringing. Those natural string resonances will keep going for a little while, even as the player switches from a D note to a D# note. It's just part of the way the instrument sounds, and the ear gets used to it. But it's always there, as long as there are un-fretted open strings waiting to vibrate along with some passing note.

Now add the resonances of the strings between the tailpiece and the bridge. If undamped, and if they fall on some weird notes, they will stick out like a sore thumb. But "tuned" to a higher octave of the open strings, the ringing is masked by the effect of the open strings. The tailpiece strings sing along with the open strings, and nobody is the wiser.

On mandolin, people tend to use a lot of four-finger block chords, so there are many times when there are exactly zero open strings. So if you hit a chop chord, you expect it to be silent as soon as it's deadened. So we dampen the strings at the tailpiece, end of issue.

I guess the 1/8 string length thing is good for bowed instruments, but for mandolin there are different things to worry about.

[delsbrother]

Didn't the famous L&H tailpiece have little adjusters inside to fine tune the string length as well?