Wolftones?

[andybigbass]

I have a Kay M1B which I play in a blues band,who are admittedly quite loud on stage.My problem is that the bass has started to develop what I think is called a wolftone that is most noticable one the A played on the D string.I know that problems like this can occur when playing too loud,but my worry is that is didnt used to be there so something has changed/broken.
It is an oscillating sound similar to when tuning up using harmonics and can sometimes get so strong it seems to actually cancel the note out so it becomes inaudible.
I have changed strings ,tried wolftone eliminators on the after string length.I have also had some one refit the soundpost and bridge,although he addmitted himself he usually works on mandolins so maybe not the best qualified.
Could this be a sign of more serious structural damage,or could anybody suggest some "tricks of the trade" to cure it.
thanks in advance.

[Phil Rowan]

Have you tried pressing the inner side of your left knee/leg against the back of your bass when you play that specific note? I have a wolftone on the B on my D string, and this trick does the job. Although, if I play that note perfectly in tune, the wolftone isn't there.

[bejoyous]

Some things I did to eliminate my wolftones:

The part of the endpin that extends into the bass might be vibrating in sympathy withe the strings. Try changing the endpin length. If the wolftone disappears, cut off the endpin to the minimun you need to play properly.

Check the afterlength of the strings. They should be 1/6 the sounding string length. (ie. if string length is 42", then afterlength should be 7") If not then you need to adjust the length of the tailpiece wire. Also, try either a Wittner or wire tailpiece. The lower weight makes more vibrations go into the body of the instrument rather than shaking the tailpiece.

Be sure you strings are properly in tune. Use a tuner. There are at least 8 different A harmonics. They sometimes fight with each other. Maybe a string is defective giving a false harmonic and contributing to the wolftone.

[andybigbass]

yes Phil, I have pressed my knee into the back but it has little effect.
Bejoyous, I didnt know about after string length being so precise! I will check out all your suggestions.
thanks both for taking the time to help out .

[bonaventura]

Originally Posted by andybigbass

...Bejoyous, I didnt know about after string length being so precise! ...

there are those who want to work WITH the afterlength string vibrations to get the bass resonating more fully, but even those seem to agree that every bass is different. there isn't any fixed length that applies to all.

my carved bass has a wolftone, like all master carved instruments. it's in the wood, and my bass will howl on "G", particularly on the A string but also elsewhere. like yours, the string afterlength would feedback through the amp all by itself. then i got a longer tailpiece and lengthened the tailpiece string so that the string afterlength was shorter. no more wolf.

[wiro]

A little try-and-error replacing the soundpost could help. At least it did for me. If you don't have experience in this then bring the bass to a good luthier who can do it properly.

[Eric Hochberg]

Try putting a folded up towel between the tailpiece and body of the bass to act as a damper.

[dchan]

Originally Posted by ehochberg

Try putting a folded up towel between the tailpiece and body of the bass to act as a damper.

My school's bass had a big open seam between the top and the ribs. It was rattling because there was another open seam running from the soundpost-side F-hole downwards, and I had a concert coming up in a few days. So I stuck an old T-shirt between the tailpiece and the top to keep it from rattling.

It certainly stopped the rattle. But it also made a bass that wasn't setup well even harder to play. With the T-shirt stuck firmly enough to keep the rattle at bay, it was as if tail cable was made from a stiff coathanger rather than a flexible steel cable. This made the strings harder to press down and the sound less free and sonorous.

I've seen professional orchestral bassists keep a rag in the same place - they usually use it to wipe rosin off the strings. I don't know if it gets rid of wolftones or not, but it's not something I'm inclined to try again.

[Eric Hochberg]

Originally Posted by dchan

I've seen professional orchestral bassists keep a rag in the same place - they usually use it to wipe rosin off the strings. I don't know if it gets rid of wolftones or not, but it's not something I'm inclined to try again.

The towel isn't going to make up for all of the problems of your school bass, but I can tell you from experience it can affect wolftones. I'm not suggesting you jam it in to create a lot of pressure on the top. It's worth experimenting with. It also might be worth adding some weight to the tailpiece to see what effect that may have. Also, run some material through the string afterlengths to calm them down.