The Love Song For Sound
Introduction
Welcome to a Light, Sound, and Time. We focus on diving into the three concepts in great detail, learning the mathematics and ways we can apply these simple concepts to difficult situations. This unit is about sound. We learned about the spectrum of sound, how fast it travels, how material increases/decreases the speed at which sound travels, and echoes. I’m most proud of my ability to understand the mathematics behind sound, as it feels relatively simple to understand and doesn’t dive too heavily into 3D concepts, which I have a really hard time mentally picturing. On the contrary, I found myself often struggling with utilizing the vocabulary that was given and applying it verbally when I wanted to refer to sound. As for this project, we’re creating diddley bows from scratch. We create this instrument from scrap we could find at home, holding true to the previous action project’s DIY element. In this case, we used dead batteries, a wooden plank, a tin can, and metal string in order to create this instrument. Instruments are beautiful utilizers of sound, which makes it a perfect selection to pay homage to our unit of sound with an instrument that demonstrates the subcategories of sound we branched into. Through a diddley bow, we’re able to analyze pitch, frequency, amplitude, and soundwaves. Without further ado, below you will find an exploration into the geometry, sound, and creation of the diddley bow. Enjoy.The CREATIVE Process
As mentioned before, the diddley bow is created purely from resources we could find in our household, with the off-chance you might not have a piece of wood lying around or invested too much time into having spare guitar strings. Nonetheless, it's fairly cheap and easy to make if you're not me (who basically tore a guitar string because of inability to wrap it around the screws).
With the previously listed materials (can, wood piece, string, nails), we create something that looks like this: [Insert drawing of labeled diddley bow]
The diddley bow creates noise through plucking the string, which creates vibration that travels through the neck and bridge to the diddley bow's body. The wood vibrates, pushing the surrounding air molecules together and apart. The compressions create soundwaves, which escape mostly from the opposite side of the tin can. This leads to it going into your ear, which converts them into electrical impulses that your brain turns into the sound we hear. The pitch of the sound is determined by the frequency of compression.
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| Diddley Bow but I drew it by D.B 2022 |
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| Diddley Bow by D.B 2022 |
Geometry and Harmonics
Below are the measurements that I was required to do for the diddley bow, primarily including some geometry and measuring frequency/wavelengths.
Measurements:
- Thickness of string: 0.56
- Length of string: 17.91
- Height by battery: 2.5
- Pinhole height: 3.75
- Battery to can distance: 17.75
- Trapezoid area: 55.46
- Upper angle: 82
- Lower angle: 98
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| Measurements by D.B 2022 |
As for marking harmonics on the diddley bow, unfortunately my camera couldn't capture the marks on it due to the dark wood, but the lines are marked based on these fractions created from the string distance from battery to can.
⅔ = 11.8206 in.
¼ = 4.47 in.
¾ = 13.43 in
Harmonics I feel need a bit more context onto exactly what's being done in order to achieve said numbers. First, I play something called an "open note" on the diddley bow, which is just me plucking the string once and using an an audio recording app that converts the first note into a frequency.
The open note frequency was 184 Hz. We're going to be working with this to find three other frequencies and waves. For our first frequency, we've already established that this is 184 Hz. In order to find the next frequency, we simply double our current one. That makes our second one 368. We continue to do this until we've reached our fourth and final frequency.
Our frequency list begins to look like this:
First frequency: 184 Hz
Second frequency: 368 Hz
Third frequency: 552 Hz
Fourth frequency: 736 Hz
Now for our waves, we're going to bringing in the measurement for the speed of sound. The speed of sound travels at 343 m/s. Using this, we place it into our formula of wave speed/frequency. In this case, wave speed is 343 m/s, and we'll be using our four different frequencies to find our four different wavelengths.
343 / 184 = 1.864 m
343 / 368 = 0.932 m
343 / 552 = 0.621 m
343 / 736 = 0.466 m
The Finale
Now that we've gone through all the lovely science jargon together, I'd like to introduce you to the finale. In this finale, you'll be hearing possibly one of the greatest pieces of our time, or perhaps even of all time. I know you're just absolutely anticipating the reveal, and I can't hold it off from you for too long or else this seems quite unprofessional from a graded aspect. Without further ado, below you'll find my recorded piece of music wonderfully played from the hands of the most skilled guitarist you've ever lend your ears to.
Conclusion
I don't think I was made for crafts. Making this diddley bow was the most difficult thing about this project, as tying the string around the screws broke my spirit quite quickly, along with the actual string I was using out of frustration. I ended up getting a new one and using some home tools in order to get this done right. As for mathematics, it was a lot of mental gymnastics for somebody that doesn't understand math to find a way that works for me. I ended up making sense of it after a good while, and it felt pretty easy once I did. For me, it's a matter of understanding the "why" of mathematics before the "how." It becomes a mental roadblock unless I feel satisfied with the answer as to why I'm applying said formula. In the end, it was a fun and chaotic time. We had to build the diddley bow in the Harold Washington Library since our new space wasn't open, and I pitied the folk that were reading or studying on those two days. We were using hammers and nails and putting it into wood, possibly the loudest thing a class could be put to do in a library.
That's about it. If you're planning on doing your own diddley bow, I hope that my post provides some reassurance in your process and good luck with the string part of it.
