Double Bass C Wolf Tone?

[Quentin MCB]

Hello! I have a wolf tone on a C (C3, not C2), very present when playing C on my G string, but also on my D string. I read that wolf tones on double bass are usually lower (around A), should I worry?

Also, I will get a wolf tone attenuator, but I already wonder on which string I should place it. The afterlenght of my A string sounds like a slightly flat C, is it linked to the wolf tone?

 

[Quentin MCB]

Up?

 

[Mark_T]

Basses I have owned/played have generally only had wolf tones in the G to B flat range, and less present on the G string. I don't recall anyone reporting a wolf pitch that high before, but who knows?

It's worth trying a variety of wolf eliminators. The String Emporium has a set of 3 at differing weights, but the LupX works too (that's what my bass has now).

I usually see wolf eliminators on the A string so I'd start there. However, at one point I found it effective to put the wolf eliminator on my D string, so don't restrict yourself. I generally want to place the eliminator as close to the silk windings (towards the tailpiece) as possible while still moving the wolf to an out-of-tune pitch (you can't really eliminate it, you just move it to a pitch you don't play).

In my experience, the closer the weight is to the bridge, the larger the impact it has on the wolf, but also generally the more it changes the sound of the bass. I am always looking for the balance where the bass is as free as possible (i.e., unaffected by the wolf eliminator) but the wolf is suppressed/moved to a tolerable level.

Based on the unusual location of the wolf, you may want to try some other things too. A soundpost adjustment might help. Retuning the afterlengths could also help. Those will require the help of a qualified luthier.

Last, depending on the kind of material your tailgut is, you can try widening or narrowing them where they cross the saddle. My bass came with a dyneema or kevlar cord tailgut and it's flexible enough that I can squeeze it together or force them apart slightly, and that can affect the location of wolfs on my bass.

 

[Co.]

What I would do first, is checking the instrument for any resonances on that specific pitch. First check the pitches of the afterlength, then tailpiece, fingerboard and everything that could also be vibrating on a more or less specific pitch. Once you have found the resonance, try to dampen or alter it somehow (manually, with a piece of cloth, a tennis ball, an assistant,...). If this temporarily helps wit the wolf, please report back, so we can find a more permanent solution.

 

[DoubleMIDI]

A weight on a string is a discontinuity in mass. Which leads to a partial reflection at that mass. So the afterlength got tuned up for the reflection but also tuned down a lot in the lowest mode of vibration for the the energy that is not reflected at the discontinuity. The afterlength with a weight on it has even more deviation of the partial frequencies to the harmonics than without one. But even without the weight the underlength is in harmony c because the mass changes where the metal windings got spread under the silk (and due to the additional mass of the silk).
So trying different positions by slightly moving the mass along the underlength that has a similar frequency as the wolf (a few octaves higher) would be a good idea.
I haven’t tested it myself, but I would start with the mass at the tailpiece.

 

[Co.]

I haven’t tested it myself, but I would start with the mass at the tailpiece.

I tested a lot with wolfy fractional student basses. Almost always, some kind of mass under the end of the fingerboard improved the response of the problematic note. Can be done with museum putty (patafix or similar in Germany), with or without additional lead weights.

 

[Mark_T]

I tested a lot with wolfy fractional student basses. Almost always, some kind of mass under the end of the fingerboard improved the response of the problematic note. Can be done with museum putty (patafix or similar in Germany), with or without additional lead weights.

Did you put the putty at the end? Off centered? Or just play around until something worked?

 

[Co.]

Did you put the putty at the end? Off centered? Or just play around until something worked?

I put it under the fingerboard (under meaning opposite of where the strings are) at the end of the fingerboard, so you don't see it but the leverage of the mass is maximized. Not off center, right in the middle. That is the place, where it is most effective. Fine tuning is done by varying the mass.
I also did this with a violone and a treble viola da gamba. It always worked, but it also makes the sound a tiny bit less open. Always a compromise.

 

[Quentin MCB]

Thanks for you answers! When I get home next week, I will try with a weight on the A string afterlength, which is currently tuned to a slighty flat C. But I think I'm also going to take it to the luthier to get his advice about soundpost adjusting, since it seems weird to have a C wolf tone.

I have a very large 3/4 carved bass with flatback, the unusual geometry of the instrument exlpains maybe this odd wolftone.

 

[gnypp45]

I have played two very good basses with unusually high wolf tones (B and C). I would't worry about it.

 

[Quentin MCB]

Update, I've put a dampener on the A string afterlenght, really close to the bridge, it seems to reduce the wolf tone, although I find my bowed C sounds still weaker than the adjacent B and D

 

[Mark_T]

Did you try the weight on the D or G, just for the sake of comparison? It sounds like a big improvement either way.