Double Bass Didn't know where to put this one....

[Tbeers]

Today I played a concert in Bushnell Park in Hartford. Near to the stage where my group was playing, there was what appeared to be a large power generator that was making a constant, low rumbling background noise. While the noise of the generator was really minimal and hardly noticeable, it was having the oddest effect on my bass.

Whenever I took my fingers off the strings, my bass would start echoing the rumbling noise. I looked over and sure enough, the D-string was vibrating wildly and getting louder by the instant. I muted the string, it stopped, then I took my fingers away again and the same thing happened over and over!

Has anyone else ever experienced this? I'm thinking something about my open D string was in perfect sync with the generator, or something.... But it sort of freaked me out and I don't fully understand what was going on.

It was funny though. While we were warming up, I said to the sax player, "Look! I can play with no hands!" He was pretty impressed when the D started itself up and got progressively louder until it seemed my bass was about to break.

 

[anonymous0726]

You had a PA system there too?

 

[Tbeers]

You had a PA system there too?

Yes. And a subpar one, too.

And the sound guy insisted that I use his direct box as opposed to the DI on my AI Clarus head (which provides what I consider to be an excellent signal). But that's a separate issue.

 

[Silversorcerer]

My guess is the generator was humming a "D" or some harmonically related frequency. I have had a similar problem occur in the opposite direction. For instance playing an open "A" and having a heater return duct rattle wildly every time I hit that note. And we played that place once a week.

 

[Damon Rondeau]

FWIW, the North American AC system runs at 60 hz, which is somewhere between a Bb and a B if I remember correctly.

 

[ToneRanger]

the D started itself up and got progressively louder until it seemed my bass was about to break.

I once played a gig on a big motor launch on the river - a similar thing happened with the boat's engine resonating the floor at various notes as the revs changed. The engine eventually settled on a note about half a semitone below E - which made all our bluesy song in E and A sound out of tune.

 

[anonymous0726]

And the sound guy insisted that I use his direct box...

It sounds like you have to learn some sound-dweeb management. When they insist on a DI box, I tell them that I will give them the direct out from my WW (with some gentle explanation, of course). But, if they insist, they can put up a mic and be happy with that. Overall, if they look too untrustworthy I tell them that A) No DI and B) the direct send from my amp doesn't work, so use a mic.

 

[Nick Lloyd]

You can also win a sound guy over with the mic-on-the-amp solution. (I don't know if that's what you were referring to, Ray...)

btw- A friend told me that the "effects send" on my GK is a post-eq signal, that is... the sound man gets the signal I want to send him, not direct off the bass pickup... is this true?

 

[Damon Rondeau]

btw- A friend told me that the "effects send" on my GK is a post-eq signal, that is... the sound man gets the signal I want to send him, not direct off the bass pickup... is this true?

Dunno about your GK but it's true of the AI Clarus. The sound guy can still do evil things with your sound.

 

[Brent Norton]

Does your GK have an actual D.O.? I *think* most GKs are pre/post switchable...

 

[robgrow]

You can also win a sound guy over with the mic-on-the-amp solution. (I don't know if that's what you were referring to, Ray...)

btw- A friend told me that the "effects send" on my GK is a post-eq signal, that is... the sound man gets the signal I want to send him, not direct off the bass pickup... is this true?

The signal from the effects send jack on the GK MB series amps is Post EQ, but before the output level control, which is nice, since you can adjust your own monitor level without changing the level you are sending to the sound man.

 

[Nick Lloyd]

thanks!