Double Bass Wolf Tone From PA?

[drwv]

I've twice experienced what might be a "wolf tone" and they were when performing with venues' PAs. When I'd play F# on the D string it jarringly sounded like the instrument played a second, different note simultaneously. It didn't happen every time I played F#, nor for the entirely of the set. I've never experienced it when playing acoustically or with small amp support.

Is this a feedback resonance? Is it a wolf tone that I'm just not perceiving when playing acoustic (I play pizz only)? Am I just making excuses for my poor intonation??

I've got a "loud" gig coming up and am afraid the wolf will bite me again, but am not sure how to preempt it.

Bass is a '74 Engelhardt with Realist LifeLine to FDeck HPF-Pre.

 

[stefaniw80401]

Yes. Both. Flip the phase switch on your FDeck HPF-Pre and see if that helps.
If you have EQ you can cut/notch around 98Hz (open G) or 93Hz (F#)

 

[AGCurry]

It sounds like the room had a certain resonance, and your F# came close enough to it to excite that resonance.

 

[Dr. Love]

Yup, I've had that happen. A piezo pickup doesn't care where the vibration is coming from: if it feels it, it sends it. I had one especially miserable gig where every time the drummer hit his toms my bass went into wild resonances with nearly uncontrollable feedback due to a combination of overall volume level, subwoofers under the stage, and a soundguy who was trying to mix us to sound like a dance club track.

My method for loud stages has been: FDeck and play with the HPF and phase, foam under the tailpiece and sometimes between the afterlengths to deaden that side of the bridge, then position myself between the bass and any direct sound sources like amps and monitors. I also made some foam f hole inserts to plug the holes that I've only had to use a couple times as a last ditch effort if the first stuff doesn't control it.

 

[brianrost]

Subwoofers under the stage...ugh. I've done gigs like that where luckily I had a magnetic pickup on the bass as well as the piezo and used that. Otherwise the bass would just feedback from the vibration of the floor.

 

[stefaniw80401]

Subwoofers? Our secret weapon is our HPF, which will cut them off at the knees! If the SP tells you to open your HPF, then I think we have the right to ask them to turn their subs way down.

 

[drwv]

Thanks for all of your wise responses so far!

To be clear: This wasn't obviously "feedback". We did a soundcheck on both gigs, had FOH support, neither PA had subwoofers, and none of my own notes or bandmates' notes triggered that "she's about to howl!" runaway feeling in the bass. I always have my FDeck HPF-Pre, and always chop the low-lows out; have flipped the phase polarity before to deal with feedback on cramped stages, but these weren't those situations.

It just sounded/felt like when I played the F# on my D string - sometimes - the bass would emit two different notes instead of just one, and slightly louder than a normal note.

These weren't super-loud gigs - a church sanctuary and a restaurant - but our next gig will be on a loud rock stage. I'm prepared to deal with feedback, but looking for advice on how to kill this wolf note that I can't reproduce at home.

 

[drwv]

If you have EQ you can cut/notch around 98Hz (open G) or 93Hz (F#)

I do have another preamp with a notch filter.

I obviously play the F# when I need an F#; it'd be interesting to hear whether cutting the fundamental with a notch filter kills the wolf and still allows enough harmonic content to produce a clean-enough F# note.

(My other preamp is the new-ish EBS Stanley Clarke. Despite it costing five times as much, I prefer the simplicity of FDeck's HPF-Pre instead!)