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In the Forum: Audio Discussions
In the Thread: Sounds of Science
Post Subject: Ayemtrical responsePosted by Gargoyle on: 8/22/2024
if I compare the air to the hot molten plastic in a glue gun. A glue gun one can pressurize easily in one direction but cannot retract in the other direction. The reason being there is no fixed plunger, like a syringe would have.
In the case of the video the air has to come from somewhere, assume to replaced by atmospheric pressure. The resulting output would be more asymmetrical than sinusoidal, acting like a toy "put put" boat, or pulsing water flowing through a anti-back flow check valve.
So if the output of a resonating pop bottle "horn" is visible, there should also be asymmetrical output from a regular horn speaker.
If the low frequency cutoff of a horn and regular speaker are the same size, then main difference being the horn has a third dimension whereas a regular
speaker is 2d.
My hypotheses is that the flare of the horn is ideal shaped to help refill the horn with atmospheric pressure and less to do with the absolute outward pressure wave. (Or potentially with realignment of waveform distortion, 2 sides of the same coin.)
The outward pressure wave is like breaking billiard balls, the shape of the triangle should be a little more forgiving. The specific empirical founded flares should ideally help to re-rack the air left in the vacuum, to hold local air molecules in that racked orientation, as the driver cannot effectively pull air back into the horn. (Though I acknowledge that other parameters are chosen for other reasons.)
Another angle/example of using a vertically oriented horn using sand instead of air, gravity replacing the atmospheric pressure. You would see something that looks like it's pulling sand in as easily as it is lifting it up. If the horn is shaped nice enough and ignoring the fact that a lot of shapes may have other problems with internal and external room reflections going back inside etc, the flare probably doesn't matter critically for the outward pulse as once it leaves the mouth of the horn it has left the planet. I can't hear air that is inside the horn, or the room, just the pressure on my ears. What an odd thing to say.
Not really as the amount of energy in the room with regards to air molecules bouncing around is a lot more than I could measure in one place with a microphone, or a pair of ears. 1000 microphone would have 1000 times the power and none of them could repeat the same thing as the other.
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