Double Bass Wolf or Sympathetic Vibration

[bluefizz]

Hey all, was wondering if anyone has had the same issue or knows how to fix.

I’m primarily a jazz player that plays with combos and big bands. Currently I’ve been having issues with the Bb-B-C on the G and D strings, but primarily the B. When played, the entire bass vibrates, especially the E string. Even when I let off the string, the bass keeps vibrating. Acoustically with a bow, and with an amp it’s loud and muddy.

I use a Headway preamp with either a Realist Lifeline or Myers Mic over the G string F whole. When I use a narrow notch filter at B frequency it kills all the tone and fullness. I have tried the ball behind the tailpiece, didn’t help. I tried muting the E at the nut, but it didn’t help either.

I don’t get wolf tone oscillation when I play B or E. Have had Lisa adjust the sound post and bridge a few times, string after length, spiros, Evahs, Perpetuals. Because of this, I assume it’s because the natural sympathetic vibration of the bass is B.

With that said, the bass plays and sounds great otherwise.
Current string setup: Spiro Weich E, Evah Weich A and D, Gaumt Lyon G.

Anyone have any ideas how to tame the B or am I hunting a unicorn?

 

[AGCurry]

What happens when you play those notes on the D string? If it's a similar result, it's probably a wolf tone.
I am surprised that your luthier (Lisa Gass?) has not tried methods of wolf-tone elimination.

 

[bluefizz]

What happens when you play those notes on the D string? If it's a similar result, it's probably a wolf tone.
I am surprised that your luthier (Lisa Gass?) has not tried methods of wolf-tone elimination.

Same Deal on the D string. Tried last night with a bow in thump position on the G string and it happens there too.
I’m probably going to give her a call and see if I can stop by today and get a wolf tone eliminator.

 

[Greg Clinkingbeard]

I had a similar thing but only amplified. This bass has remained unchanged since the summer (long time for me). Two weeks ago I noticed the E string might be a little weak so I moved the post toward the G f hole and was happy with that. I honestly don’t remember if I fit a different post. That was until I played a trio gig and the D string fed back badly. I haven’t had any feedback issues when using the Lifeline pickup so it stumped me.
The post in the bass is made from tight grained old spruce and sounds very bright when dropped on the floor. I fit another post with wider grain and a darker ring when dropped on the floor, ever so slightly shorter. It is fit maybe a mm or two further below the bridge but about the same east to west. I’m fairly skeptical about dropping posts and bridges on the floor, but when changing problem posts I often go with one with a real difference. While I was at it, I noticed that the E adjuster was slightly touching one corner of the foot (threads down) so I fixed that and removed a mm from the legs to allow just a bit of threads to show.
Problem solved. Using the same amp, I had the volume up pretty high and had an even, feedback free result. The bass sounds darker and more even acoustically as well.
Chasing these things can be maddening and I’m not sure which minor adjustment to credit. The old post may have had a slight gap at the back or it may have had the wrong resonance for the bass, or………. Go back to square one and be sure of every step along the way before thinking it might be a wolf tone. Most are closer to an A.

 

[bluefizz]

I use to have all types of issues with open D causing feedback. Not to sure where the sound post is in relation to the bridge. I have had it adjusted a few times for a more focused sound and to try and stop the D from being so sensitive when amplified, which is probably the issue now that it’s been played for 5 years. I put on a wolf tone eliminator I had on the A string a little over an inch from the bridge and it help with the B and C, but now the A is over powering lol.
I’m going to take it to the shop in a few hours for a sound post adjustment and test it with an amp while I’m there.