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FYI 'quivering boom pole'
I set up QP6200 ambient jumbo pole on a heavy doughty stand...with many ballast bags of sand around base as well as counterweight on boom.
Sprung gym floor.
every time people walked the vibrations set up a resonance along the boom and it started gently wavering up and down at the tip....mics moving a good few centimetres in the vertical.
I cannot detect problems in audio recording (but these were lower school orchestras and they anyway wavered a bit!)
an interesting challenge as the issue is not horizontal or back and forth and stabilising with guy lines seems precluded.
There were no air movements beyond any thermals created by audience ??
I willed it to keep still but it did not.
we will try to experiment with different extensions and curvatures of the boom to see if issue can be minimised or exagerated and therefore understood
just a thought that someone may be interested!
Seriously, parameters that affect the resonant frequency of the floor/stand/boom/mic system include pole length, weight and stiffness; weights of mic and cable; and height and stiffness of stand. Playing with one or more of those may shift the resonant frequency enough that someone walking by at a normal pace won't set up a resonance in the system. Or put a thin tight guy line from the mic to the stand some distance from the boom so the tension will stabilize the boom and mic.
The sprung gym floor is a factor otherwise not present in most performance venues.
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Technical Editor, Sound On Sound