Bass reverbarations of large volume explosions?

[rsgpitt]

Does anyone have an idea why this happens. In small scale baloons, or long skinny balloons, they have high pitch firecracker like explosions. The longer these twisty baloons are the louder they are. When you take a large spherical balloon with 6 inch diameter greater, it makes an extremely bass note with chest shaking vibrations, but very little audible noise. Why is this?

[Cryptonic26]

Not an official answer or anything, but heres how I understand it.

First, We know that high frequency sound waves are short, and low frequency sound waves are long. The human ear cant hear very short sound waves too well, but we can feel them; This is your Bass reverb.

Second, A given weight of 2H2:O2 at room temperature has a specific volume. When you add energy (a spark, a flame) this gas reacts, H2 and O2 splits from its diatomic state (-> 4H:2O), so that it can reform as a pair of 2H2O of molecules. This process causes a rapid gas expansion. When the elements re-bond as steam, an implosion occurs.

(1 liter of O2, and 2 liters of H2 produce only 2 liters of Steam)

This expansion->implosion causes a wave to propagate outwards from the reaction through the atmosphere as a sound wave. (just like a PC speaker changes volume to produce sound waves, so does this reaction.)

Given this, it becomes easy to see why different volumes of expanding gas produce different length sound waves. More volume gives longer sound waves (Bass), less volume gives short sound waves (Treble).

I'm not sure of the exact volume difference between 2H2:O2->4H:2O but if you knew the ratio, you could calculate the produced wavelength fairly accurately.

[whitehat]

you mean 1 mol of hydrogen and 1 mol of oxygen makes one mole of H20(g)