Wolf Eliminator Cello (Frequency Selection), ZD-231
ZD-231-A
Wolf note eliminator for cello from our own production, with selectable frequency.
- Several masses to choose from
- Fits between bridge and tailpiece
Technical data
| Instrument | cello |
| Fitting | between bridge and tailpiece |
Features
- For cello
In practice
- A wolf note arises when a body resonance coincides with a stopped note. The cello is mainly affected, most often around F and F sharp, less often between E and G sharp.
- The eliminator is fitted on the string section between bridge and tailpiece and deliberately detunes that section by adding mass.
- You move the position until the wolf disappears.
- Because the mass also damps the string, the rule is: as light as possible, as heavy as necessary.
- Beyond that, the wolf can be influenced by a change of strings or by the violin maker adjusting the soundpost.
Versions
- A to tief d-e, ZD-231-A
- B to mittel es-f, ZD-231-B
- C to hoch e-fis, ZD-231-C
- D to special f-g, ZD-231-D
- E to special g-a, ZD-231-E
- F to special fis-gis, ZD-231-F
Sound and physics
A wolf note arises when the frequency of a bowed note coincides with a strongly coupled natural resonance of the body; the note then finds no stable state, it stutters or jumps. On the cello the wolf most often speaks around F and F sharp, less often between E and G sharp; on the G string that puts it in a high position.
The vibrating system to which the string is coupled also includes the string section between bridge and tailpiece. An eliminator on this section damps and shifts the resonance, so that its peak (the amplitude at the top of the resonance) falls. It works where the troublesome vibration has an antinode; in the wrong place the wolf merely moves to the neighbouring note, and if it is too heavy it also damps the neighbouring notes.
The ZD-231 wolf eliminator for cello comes in six variants, each tuned to a pitch range: A low d-e, B medium e flat-f, C high e-f sharp, D special f-g, E special g-a and F special f sharp-g sharp. The choice follows the pitch at which your cello's wolf sounds. Like every eliminator it sits between bridge and tailpiece on the string section that belongs to the wolf's vibrating system.
Our experience
Our experience: we fit the eliminator to the string on which the wolf sounds, start with 7 grams and go one step heavier or lighter from there. Sometimes it is precisely a heavy weight on the A string that helps.
When another model suits you better
If you would like to choose the weight in fine steps, our ZD-251 to ZD-255 eliminators offer five masses from 3 to 11 grams.
Frequently asked questions
Do fine cellos have a wolf note too?
Yes, cellos by famous makers have their wolf too; it arises exactly where body resonances are strongly coupled.
Where do I fit the wolf eliminator?
On the section between bridge and tailpiece of the string on which the wolf sounds. Then move it until the wolf disappears.
What helps if the eliminator alone is not enough?
Rossing names further options: a change of strings, which alters the mass per unit length and with it the coupling, and an adjustment of the soundpost by the luthier.
Which ZD-231 variant fits?
The variant whose range includes your cello's wolf, for example the ZD-231-C for a wolf around e to f sharp.
These texts hold decades of experience and a great deal of heart. They are protected by copyright, C.A. Götz jr. GmbH. Please ask us before any use. Thank you for your appreciation.