Tailpiece vibrations

[dpappas]

I understand that tailpieces can vibrate quite a bit and that, if the frequencies are in playing range it can potentially sap power.   
 

I touched my tailpiece (boxwood, 12g, 5 mm gut length with 54 mm after length, nylon) while playing and I was surprised by how much it vibrates.   I put some clay (8g) on it and the instrument gets darker/mellower.  I wonder how tailgut length/stiffness would impact things.  
 

I’m not looking for a change, just some understanding.  

[Don Noon]

The primary rigid-body modes of the tailpiece (where the fat end moves most) are generally around 130 - 140 Hz, below the playing range.  It probably is close enough to open G (196 Hz) to kill off some of the fundamental, but it's so low anyway that it's probably not a big deal.  It's probably a bigger deal for violas if a very light tailpiece is used.

Much more important, IMO, is the mode where the end of the tailpiece is sprung by the tailgut.  That mode, although less strongly coupled to the bridge, IS in the playing range.  The longer the free tailgut length, the lower the frequency and the stronger it will vibrate.  I generally try to keep the free tailgut length as short as possible (less than 5mm), which puts the resonance higher in frequency and weaker in effect.  This mode can be carefully tuned to act as a wolf killer, but it's a pain to get the tuning right, and the transient response gets funny... so I don't bother any more.  Tailpieces with a sliding mass or screw-adjustable free gut length might be easier to tune, but there's still the transient oddness.

I have never found any effect from modes where the tailpiece itself flexes, but I wouldn't discount hyper-sensitive players that might notice.  Or imagine that they do.

[dpappas]

Don,

 

that makes a lot of sense from what I’ve read here.   Generally I agree shorter tailgut is better (and probably that major factor in moving a tailpiece, more than afterlength effects).  I wonder if the strad pet pro tailgut, which is titanium wrapped Kevlar, would be good vs the nylon, if both are super short.   
 

thanks for the detailed answer.  I was going to measure the fat end vibration but haven’t had time. 

[nathan slobodkin]

Don,

Three questions:

When you say "it's a bigger deal for violas" are you saying lighter is better or heavier?

How about on cellos?

Have you experimented  with rigid tail piece fasteners such as stiff bent wire?

 

 

[Don Noon]

41 minutes ago, nathan slobodkin said:

Don,

Three questions:

When you say "it's a bigger deal for violas" are you saying lighter is better or heavier?

How about on cellos?

Have you experimented  with rigid tail piece fasteners such as stiff bent wire?

1) Since violas have a playing range down to C (131 Hz), a violin-like tailpiece would have a fundamental mode right around that range.  Even with a heavier tailpiece, it's still going to be close in frequency.  Lighter I think would be worse, raising the resonance higher into the playing range.  I tried a lightweight viola tailpiece once.  Not good.

2) I don't have to worry about cellos, since there's no way I'm going to work on them.  The same basic physics would apply, but I have no clue where it all ends up.

3) No, but I have seen a thick solid-strand wire tailgut on a Strad... which was later replaced with nylon.  If the wire is stiff enough, it could raise the 135Hz mode enough to be a problem.  I have tried Kevlar chord, which was awful... not stiff enough, and allowed too much vibration at the lower end.  Nylon is good, once you get past the initial stretching.

[baroquecello]

On cellos, my experience is that a shorter tail cord often help string response and core of sound of the lower two strings.

Mostly, lighter is better, but not always. High quality carbon fibre tail pieces (Kenneth Kuo and Concarbo, both handmade, the latter from Ukraine and about 150 Euros, depending on the version you buy, the former around 700 dollars) are the new thing in celloland, everyone is buying them. I've installed them on two cellos with major improvement in dynamics, evenness across strings, and string reponse. It opens up the sound a lot, and makes the cello MUCH easier to play. Also, it seems to also focus the wolf note on a single pitch, instead of it influencing a whole range of notes.

[Andreas Preuss]

more important for violinists is probably the tailpiece material itself. Soft materials like Turkish boxwood tend to mute the sound. For the same reason Fernambuk tailpieces can add some brilliance if needed. 
 

For the tailpiece vibrations I noticed that. the width between tailguts on the lower saddle can enhance or reduce the overall feeling for the lower strings. Set wider apart an over resonant g string can be smoothed. 
 

All those effects from the tailpiece are rather fine tuning effects to be adjusted to the comfort of an individual player. 

[Andreas Preuss]

7 hours ago, Don Noon said:

I have tried Kevlar chord, which was awful... not stiff enough, and allowed too much vibration at the lower end.  Nylon is good, once you get past the initial stretching.

I switched almost entirely to Kevlar because the response of the strings tends to be better than nylon. 
 

The stretching takes pretty long.  In general after the initial setup and maybe a month of stretching you think it is ok. But if the instrument returns after one year a nylon tailgut got again 3-4mm longer. (The reason why I never throw an old nylon tailgut away.)

[dpappas]

Andreas,

I assume you mean nylon stretching vs Kevlar knot compression.   I have seen nylon stretch quite a bit over time, it seems the be the major and only drawback as a material.   
 

The softness of the tailpiece wood makes sense.   I might set up a rig with strings and a hanger just to decouple from the instrument and see what frequencies are impacted.  

[fragslap]

https://www.youtube.com/watch?v=KzCuI7eEweQ

Just as a curious side note, in this old video, Michael Rabin's chin almost reaches the strings.

That MUST have dampened any tailpiece vibration. I wonder what effect it had on the sound.