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Posted by Gargoyle on
08-22-2024
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A junk drawer to keep a collection of potentially useful yet spammy thoughts confined to one space.
Something about this part of the video resonates with me https://youtu.be/rYrdiQckGhw?si=mDbgjCyFJknNLJid&t=149
I've twisted my brain into a pretzel trying to consider it as analogues as a horn playing inward toward a 2 liter room creating pressure down the throat toward the missing driver?
Or take it at face value as an ugly horn may burp air out the mouth?
It is interesting to see this ported enclosure take on a bias towards locomotion instead of the expected stationary air spring. It could just be an air pulse can be forced out of the bottle a bit quicker and easier than it is to be squeezed back in.
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Posted by Gargoyle on
08-22-2024
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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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Posted by Gargoyle on
08-23-2024
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examples of cymatics in nature are hard to find.
I searched for and found a video from the CBC that had some good examples in it, but the fuckin communist say it's not available in my area. (Nazi is too kind of word) I'm a canadian, in canada and the CBC is funded by tax dollars. Thats what happens when you live amount idiots. Just occupy them with stories how the orange man is bad. If canda goes bad, we absolutely fuckin deserve it. All of it. What they don't realize is that the MAGA hats will run the archipelago.
It is understandable that an organism could evolve to work with the resources are around it, to me it's more off a question of what was making the sound that the shell of the trilobite grew into?
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Posted by Gargoyle on
08-23-2024
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revolve around things like gas bubbles through lava, wind noise acoustically filtered through water. Hydrothermal vents plating like pipe organs is an interesting thought. Pure sounds are preferred, ones that have the golden mean ratios and lack harmonics.
Some thoughts of viruses actually being older than bacteria due to their geometric morphology.
Here are some smaller scale examples, some diatoms. I assume the real animal is on the left, but in reality to my uneducated eye I can't distinguish which one is the animal and which one is sound.
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Posted by Gargoyle on
08-25-2024
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I have been considering ventilation of the horn surface, as counter-intuitive as that is. If you have ever seen an "eductor" nozzle in a fish tank you will know what I mean.
Consulting GPT and pushing past the pedestrian answers and cautions to obvious problems of ventilating a horn, it seems to agree that conceptually at least, there could be some benefit to the lower frequencies in particular.
In my mind I pictured a bunch of circular vents that were "light tight" to have a constant hard surface to propagate sound off, but does not have the suction of a solid surface.
ChatGPT suggested venting the connection where the driver meets the horn. That's clever, it avoids some issues it was concerned with originally.
I added my depiction of circular vents farther down the horn, it identified some benefits of that, being more gentle and phase friendly maintaining good impedance matching.
There is no free lunch, necessarily, however I don't see why the output "has" yo go down, it could increase. I would be fine with a decrease if there was a benefit to lower frequencies. (Quality)
Venting is likely to benefit below 1kHz.
Mid range would have a neutral impact 1kHz - 5 kHz.
High frequencies would be negatively impacted 5kHz and above.
The thought of using a reed valve to reduce back pressure occurred to me but I don't think it's worth something potentially as difficult as that yet. On a big bass horn that might be the ticket.
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