Ok so for part of my Physics investigation i've to investigate the resonance frequency of an air column in a tube.

What happens is a vertical tube, with an open top and a closed bottom with a tap attached is filled with water.
A frequency is played into the tube using a speaker and the water is slowly let out. At a certain level of water the note being played into the tube becomes noticeably louder, and when this level of water is passed it goes back to it's origional volume.

So my question is why does the note go louder at that certain water level?

I've tried googl'ing and stuff but i can't find the actual physics behind the experiment anywhere.

Help is much appreciated
I know the answer I think.
sometimes I see us in a cymbal splash or in the sound of a car crash
The oscillations of the waves in the water is at a perfect harmony meaning that there is constructive interference as opposed to destructive interference. It's the same thing as breaking a wine glass with sound. The wine glass vibrates more and more as each sound wave hits it and then it breaks from the rapid oscillations and the characteristics of glass (easy breakability). Simple enough?
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Quote by gtdude114
The oscillations of the waves in the water is at a perfect harmony meaning that there is constructive interference as opposed to destructive interference. It's the same thing as breaking a wine glass with sound. The wine glass vibrates more and more as each sound wave hits it and then it breaks from the rapid oscillations and the characteristics of glass (easy breakability). Simple enough?

Ah yeah I understand now
Thanks alot
Waves is not my favourite part of physics
It's something like that. If there was a picture or something like that I can really tell you why it happens. More than likely, it has something to do with the depth of the water because water is let out slowly then a note is heard louder.
Guitars:
Ibanez RG4EX1
Epiphone SG w/EMG's

Amps:
Peavey Windsor Head w/ JSX Cab
MicroCube (for the sake of practice at college)

Pedals :
Fulltone Full Drive 2 Mosfet
Digitech Whammy
Dunlop Crybaby
Quote by Cyanide176