fractional size and setup

[baroquecello]

As a cello teacher I have a lot of students playing fractional size instruments. In almost all cases I think they do not work as good as they should, and I suspect as they in fact could. Ofcourse, a lot has to do with the brand of strings, but occasionally I come across a small cello that works very well, and I wonder why others don't.

 

Strings that I have found to work best on 1/4 are Spirocore, for 1/2 Spirocore and Helicore, for 3/4 the sprirocores are not so good for the a and d strings anymore, and Larsen kicks in.

 

Most small cellos, when strung with the above brands, surprisingly do not have a problem with the lower two strings. Evidently they don't sound as good as full size lower strings, but they work. The top two strings however, are nearly always problematic. They need a lot of bow pressure and slow bowing for responding, and even then sound quite terrible. This problem is worst with the most expensive set of fractional size strings that I know: Larsen strings. The a from Larsen has been terrible on any fractional below 3/4 size cello I've played.

 

But as I said, occasionally you find a cello that works. Currently I have a student with a 1/2 Cello from the early 80-ies, terrible Nitro varnish, heavy wooden tailpiece with screwed on fine tuners, but with a set of fractional size spirocore it has a good sound and a good response time, quite good playing characteristics. Why is that?

 

I'm wondering if there can be done more for the setup of small insruments than usually is done. I'm wondering wether these proportionally thinner sound posts really are better, are they not maybe too flexible? And I'm wondering wether the instruments maybe need sound posts fit with a little tension instead of without any. I'm wondering wether heavy tailpieces may work good on smaller cellos because they stop the small bodies from being "overpowered" by too much resonanse from the string, that would otherwise cause a kind of wolfy effect that makes them hard to bow. Can anyone comment on the special tricks for making fractional size cellos, in particular 1/4 and 1/2 cellos, work well?

[Craig Tucker]

  Can anyone comment on the special tricks for making fractional size cellos, in particular 1/4 and 1/2 cellos, work well?

 

My experience with fractional size school cellos has much to do with how they come, or how well or poorly set up they come from the manufacturer.

 

Most have soundposts that are forced in, and don't fit well, right from the start.

Sound posts on cellos must be (very much like the violin) tight but not forced in. Then, they must be, or have, faces that actually mimic the shape of the inside surface of the plate where they will be set.

Both plates. 

This is almost impossible to get right from the manufacturer. Then, also, from either the manufacturer or from whoever got the cello in the mail, either they set it up themselves, or had the music store set the fractional size (or full size - no real difference there) up - where they habitually just get the post up near where they think it should go... 

Then there is the feet of the bridge. Which also must be fit with some precision.  Once the feet are fit and then the soundpost - well you're correct the strings seem to have a great deal to do with the tonal output.

The string height off the fb should be looked at - the nut height and the strings grooves and their (the string) distance to the fb at the nut, makes for a great deal of the playing ease...

As with violins - all of these particulars have a lot to do with how well the particular student instrument sounds and how well or easily it plays.

 

Knowing and making the basic "classical" set-up parameters correct, really doesn't change all that much, from one instrument to another, and the instrument then has whatever voice it will have, when it's set up correctly.

Changing the voice from there can be done, but the ability to do these things very often is not worth the time or expense to accomplish very invasive changes or modifications such as changing the plate thicknesses and/or all the rest of the possible etc.'s that may be involved.

That is, on many fractional size student cellos.

 

There are great sounding and poor sounding fractional size student cellos.

But the palyability of the instrument should be within a "normal or standard" range, no matter how well or poor the voice is. The instrument should be and can be set up to play well or easily.

In my opinion.

[baroquecello]

Craig, thank you for replying!

 

Let me make clear that I am talking about fractional size instruments that were setup by professional lutiers before being rented out. they believe they are doing the best for the instruments they rent out and their full size and most 3/4 size cellos are quite good for rentals. However, almost all 1/4 size and most 1/2 size cellos do not sound good nor work well, strangely enough especially the top two strings don't work. But then theres the odd one that does, and I think/hope there must be a reason for it, that can be copied.

[Craig Tucker]

  However, almost all 1/4 size and most 1/2 size cellos do not sound good nor work well, strangely enough especially the top two strings don't work. But then theres the odd one that does, and I think/hope there must be a reason for it, that can be copied.

 

In my opinion then, the answer would be a quite emphatic no.

 

if the (general) set up parameters are followed correctly, and then adjusted for each instrument, then you, in the end, must admit to the fact that wood is an odd medium to work in, and there is never going to be an equal result - in particular - with fractional sized student instruments...

Full sized, hand made, custom instruments are difficult enough to get suitable and equitable results with.

The only thing I was ever able to get consistently "correct" on factory instruments, was playability. And that would depend on the quality of manufacture - to a great degree. 

Copying tone isn't really possible.

Copying set-up is possible, within certain limitations.

If copying tone was possible - everyone would do this on every instrument - and every instrument would sound alike. But alas, tone varies accordingly.

[DGV]

My daughter plays a 1/2 size cello that I got from a friend for 300 bucks. It sounds great and even, much better than the rental she played before.

[Marty Kasprzyk]

As a cello teacher I have a lot of students playing fractional size instruments. In almost all cases I think they do not work as good as they should, and I suspect as they in fact could. Ofcourse, a lot has to do with the brand of strings, but occasionally I come across a small cello that works very well, and I wonder why others don't.

 

Strings that I have found to work best on 1/4 are Spirocore, for 1/2 Spirocore and Helicore, for 3/4 the sprirocores are not so good for the a and d strings anymore, and Larsen kicks in.

 

Most small cellos, when strung with the above brands, surprisingly do not have a problem with the lower two strings. Evidently they don't sound as good as full size lower strings, but they work. The top two strings however, are nearly always problematic. They need a lot of bow pressure and slow bowing for responding, and even then sound quite terrible. This problem is worst with the most expensive set of fractional size strings that I know: Larsen strings. The a from Larsen has been terrible on any fractional below 3/4 size cello I've played.

 

But as I said, occasionally you find a cello that works. Currently I have a student with a 1/2 Cello from the early 80-ies, terrible Nitro varnish, heavy wooden tailpiece with screwed on fine tuners, but with a set of fractional size spirocore it has a good sound and a good response time, quite good playing characteristics. Why is that?

 

I'm wondering if there can be done more for the setup of small insruments than usually is done. I'm wondering wether these proportionally thinner sound posts really are better, are they not maybe too flexible? And I'm wondering wether the instruments maybe need sound posts fit with a little tension instead of without any. I'm wondering wether heavy tailpieces may work good on smaller cellos because they stop the small bodies from being "overpowered" by too much resonanse from the string, that would otherwise cause a kind of wolfy effect that makes them hard to bow. Can anyone comment on the special tricks for making fractional size cellos, in particular 1/4 and 1/2 cellos, work well?

 

As a cello teacher I have a lot of students playing fractional size instruments. In almost all cases I think they do not work as good as they should, and I suspect as they in fact could. Ofcourse, a lot has to do with the brand of strings, but occasionally I come across a small cello that works very well, and I wonder why others don't.

 

Strings that I have found to work best on 1/4 are Spirocore, for 1/2 Spirocore and Helicore, for 3/4 the sprirocores are not so good for the a and d strings anymore, and Larsen kicks in.

 

Most small cellos, when strung with the above brands, surprisingly do not have a problem with the lower two strings. Evidently they don't sound as good as full size lower strings, but they work. The top two strings however, are nearly always problematic. They need a lot of bow pressure and slow bowing for responding, and even then sound quite terrible. This problem is worst with the most expensive set of fractional size strings that I know: Larsen strings. The a from Larsen has been terrible on any fractional below 3/4 size cello I've played.

 

But as I said, occasionally you find a cello that works. Currently I have a student with a 1/2 Cello from the early 80-ies, terrible Nitro varnish, heavy wooden tailpiece with screwed on fine tuners, but with a set of fractional size spirocore it has a good sound and a good response time, quite good playing characteristics. Why is that?

 

I'm wondering if there can be done more for the setup of small insruments than usually is done. I'm wondering wether these proportionally thinner sound posts really are better, are they not maybe too flexible? And I'm wondering wether the instruments maybe need sound posts fit with a little tension instead of without any. I'm wondering wether heavy tailpieces may work good on smaller cellos because they stop the small bodies from being "overpowered" by too much resonanse from the string, that would otherwise cause a kind of wolfy effect that makes them hard to bow. Can anyone comment on the special tricks for making fractional size cellos, in particular 1/4 and 1/2 cellos, work well?

I will be making a tiny cello soon so this topic is very important to me.

 

Could you describe more fully what you mean by the expression "sound quite terrible" for the top two strings. 

[Christopher Jacoby]

I've found that a new Otto carbon fiber tailpiece and a kevlar gut transform most fractional commercials into viable instruments, even with Helicores or worse strapped on.

[Marty Kasprzyk]

I suspect that some of the poor sounding small cellos have top and/or back plates which are too thick and so many of their various resonance frequencies are too high therefore some notes may sound too bright or harsh.

 

A resonance frequency f of a plate is proportional to the plate thickness t divided by the length squared L^2.    f ~ t/L^2

 

If keep the same resonance frequency we find the thickness t is inversely proportional to the length squared.  t~1/L^2

 

I've attached a graph which shows what the percent plate thicknesses should be for various fractional size cellos.  As an example a ¼ size cello should have plates about 60% as thick as a full size cello.  If the top plate of full size cello has a thickness of 5.5mm then the ¼ size one should ideally be about 3.3mm thick.

 

Some small ¼ size cellos are probably made with much thicker plates (ribs too) for abuse resistance so their sound quality suffers.

Cello plate thicknesses.pdf

[baroquecello]

Well, I really don't have high expectations what the sound is concerned for these instruments, but it should be possible to get a proper helmholtz like movement of the strings going without having to use an incredible amount of pressure or a ridiculously slow bow speed. And that would result in a toe that is consistent in its qualities, it may not be very beautiful, but it should be sustainable. If an instrument plays as if it has wolf tones on half of the frequencies, and many small cellos do to a certain extend, then something is wrong, isn't there. And I find it surprising time and time again, that it usually is not the lower two strings that don't work, but the upper two. If the short swinging length of the strings would be the cause, then the problem should be worse on te lower two, not on the upper two, shouldn't it?

 

Anyway, apparently it seems consensus that I'm hoping for too much from such instruments.

[Oscar Stern]

Helicore Fractional Sized Cello Strings would be great, they're a little thinner to make bowing on the Cello easier. Fractional Sized strings for Fractional Sized Cellos have improved over the years.