Double Bass Help with unwanted reverb from the bass

[fantasticplanet]

I'm getting some unwanted reverb from my bass. The resonant frequency seems to be around Bb, and there's also a lingering E overtone when I play an A. Here's a clip (and I did mute all of the strings after playing each note):
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I still love the sound of my bass, but I haven't heard a lot of this on other basses I've played. Any ideas?

 

[Francois Blais]

A wolf note maybe?

 

[Ortsom]

Maybe it's the afterlength that is bothering you. Try damping the afterlength to see if that improves matters (see So uh.. Dampening? for suggestions).