Recorder: Recorders creates sound by splitting and vibrating the air in a tube. By covering holes on the tube it changes the wavelength and note it creates. This change is not linear like in most instruments so there is no equation such as the length of tube is a quarter of the note created like in most wind instruments. To start I played around with a normal recorder then took it apart. A recorder mouthpiece is a whistle. From there I tried to make my a whistle out of wood. That did not work out so I decided to use the top piece of the recorder instead. I then got a piece of pvc pipe and drilled holes into it. I attached the mouthpiece to the pipe and tested it. I had to try at least four other hole arrangements to get the right notes. Below is a picture showing the wavelengths of the notes and the distances between the mouthpiece and hole. There is also ratios between the hole distances and the notes they created.
The highlighted parts are the ratios between hole distance and actual wavelength of the note. The numbers are not consistent. In some in instruments there is a set ratio like a string can create a note that has a wavelength that is twice as long as string. However the distance of the holes do not match up with their wavelengths. The ratios are between 0.3 to 0.5. All the ratios differ even within the same set. So statements like the hole distance length is 0.4 of wavelength of the desired note can not be made. Most wind instrument’s hole distance lengths are a quarter or 0.25 of the note’s wave length. The recorder does not share this similarity with wind instruments.
The highlighted parts are the ratios between hole distance and actual wavelength of the note. The numbers are not consistent. In some in instruments there is a set ratio like a string can create a note that has a wavelength that is twice as long as string. However the distance of the holes do not match up with their wavelengths. The ratios are between 0.3 to 0.5. All the ratios differ even within the same set. So statements like the hole distance length is 0.4 of wavelength of the desired note can not be made. Most wind instrument’s hole distance lengths are a quarter or 0.25 of the note’s wave length. The recorder does not share this similarity with wind instruments.
Chimes: The sound created by the chimes is because of the vibration of the chimes. We were tasked to build three musical instruments, and I was assigned to build the chimes. Chimes are typically metal pipes that either hit each other or are hit by some sort of pipe or mallet, causing them to make sound through their vibration. Every material has its own natural frequency, which makes them vibrate differently. To find the right note, it takes a little bit of trial and error, since it is hard to know the natural frequency of objects and then use that to find the right note. Once I had found the note I wanted, I used a website that had all the ratios between the chime lengths and notes, so all I had to do was multiply the length of the chime I had by the ratio to get another chime with a different note. Then, I cut all the pipes to the desired length, and suspended them using screws and rubber bands. Now, when the chimes are hit, they vibrate and create different notes. When the chimes are hit, they vibrate. Sound is a vibration, so when objects vibrate they create sound. There are different notes because different lengths of pipe will create different wavelengths, which means different notes. The shorter the pipe, the higher the note. This is because longer pipes are able to create longer wavelengths because there is more pipe that is vibrating. Longer wavelengths create deeper notes. The vibration of the chime creates compressions and rarefactions in the air, which is how the sound travels to the listener, since sound is a compression wave. In conclusion, when the chimes are hit, they vibrate and produce sound because sound is a vibration.
Table for Chimes:
Note C4 D4 E4 F4 G4 A4 B4 C5
Wavelength (cm) 131.87 cm 117.48 cm 104.66 cm 98.79 cm 88.01 cm 78.41 cm 69.85 cm 65.93 cm
Frequency (Hz) 261.63 Hz 293.66 Hz 329.62 Hz 349.23 Hz 392.00 Hz 440.00 Hz 493.88 Hz 523.25 Hz
Length of Pipe (cm) 35.30 cm 33.30 cm 31.60 cm 30.60 cm 28.80 cm 27.30 cm 25.80 cm 24.90 cm
Table for Chimes:
Note C4 D4 E4 F4 G4 A4 B4 C5
Wavelength (cm) 131.87 cm 117.48 cm 104.66 cm 98.79 cm 88.01 cm 78.41 cm 69.85 cm 65.93 cm
Frequency (Hz) 261.63 Hz 293.66 Hz 329.62 Hz 349.23 Hz 392.00 Hz 440.00 Hz 493.88 Hz 523.25 Hz
Length of Pipe (cm) 35.30 cm 33.30 cm 31.60 cm 30.60 cm 28.80 cm 27.30 cm 25.80 cm 24.90 cm
Electric Bass: Typically, most string instruments such as a guitar or a bass rely on the vibrations produced by plucking the string to generate the noise. For our specific bass, we decided to make it electric by adding a pickup to it to amplify the sound instead of going for an acoustic guitar or bass. The way that the pickup works is that it consists of a coil of copper wire wrapped around screws approximately 9000 to 18000 times, and magnets are placed on top of the pickup, creating its own electromagnetic field near the bass strings. When Ashok plucks the string, it vibrates within the pickup’s electromagnetic field, and the disturbance creates a vibrating current within the copper coils of the pickup. This current is sent to the amp, via the jack, as electrical energy, and allows the amplifier to increase the volume and clarity of the bass string by a large amount. As for the way that we generate the different notes with the bass, if the lengths of the string is changed or if the tension of the string is changed, then a vibration of a different frequency is produced. Along with these factors, there is a third factor that determines the wavelength of the note produced, and that it the thickness of the string and the material that you are using as your strings. For example, a thin fishing line will produce a much higher note than the note produced by a thick copper-halfwound string, and this is mainly because the thicker strings tend to have more mass and vibrate much slower, producing a lower, deeper note, and each material has its own natural frequency, with metal tending to have a lower natural frequency. When a musician plays the guitar, they press down at certain points along the known as the frets, and when they do so, they are decreasing the distance over which the string can vibrate, thereby increasing the frequency of the sound produced and changing the note. The length of our strings were all the same, being 32”, so instead of having our open notes be determined by length, we made different open notes by varying the tension of the string and the thickness of the material. Our thickest string produces an open note of E1, then the next is A2, then D3, and finally G4. If we had used the same material and the same tension, then we would have changed the lengths of each string since the length of the string is half of the wavelength of a specific note. The reason for this is because the length of the entire string is only moving up or down at one given point, so essentially, the entire string has to go up then down to complete one wave, which is why the length of the string is almost always half of the wavelength. Our electric bass doesn’t follow this rule, because our variables are string tension and thickness. This allows us to hit the lower notes without having an incredibly long string. The looser and thicker the string, the lower the note. This is a table showing the wavelengths and frequencies of all the notes.
Table for Bass: Note E1 A2 D3 G4 Wavelength 837.31 cm 313.64 cm 234.96 cm 88.01 cm Frequency 41.20 Hz 110.00 Hz 146.83 Hz 392.00 Hz String Length 81 cm 81cm 81cm 81 cm |
Concepts:
Frequency- How many waves pass or are created in a certain period of time: measured in Hertz.
Wavelength- Length of the wave or distance from crest to crest: measured in meters.
Period- The amount of time it takes to complete one complete cycle of waves or vibrations: measured in seconds.
Wave speed- The velocity of the wave: measured in meters per seconds.
Amplitude- The displacement of the wave from equilibrium to the crest or trough: measured in meters.
Electromagnet- A type of magnet in which the magnetic field is produced by an electric current running through something such as copper wire. In this case, the electromagnet was created by the copper wire coiled around the screws of the pickup, which was connected to the bass amp.
Reflection- In my opinion, our group blazed through this project in virtually all aspects of this projects, with the glaring exception of the electronic bass, and we had a pretty fun time making each of these instruments without getting too lazy. For once, the divide-and-conquer tactic actually worked quite effectively, with each group member taking responsibility of their own instrument and delivering fully on their behalf. I think our biggest peak was how well we worked together as a group, even though we were relatively independent of one another. What I mean by that is everyone delivered on their obligation, and at times when one person needed help on their portion of the project or the justification, then another person in our group would go to help them. That leads me to our first pit, though, which was that we didn't really know much about anyone else's instrument, except for how the notes correspond to the wavelengths, which was something that we didn't have to worry about since we had the Internet. Our second peak is actually closely related to our first pit, in that we all knew almost everything there was to know about our individual instrument, and I think that the knowledge that we had was clearly demonstrated in our presentation. For example, I could have asked Andre about anything regarding the "recorder", and he would have given me an accurate, correct response, and the same goes for Nathan and Ashok. Our other pit, though, was the fact that we were so concerned about the aesthetics of the bass that we really lost track of time for the completion of the instrument, and I ended up tuning our bass right before we had to give our presentation. As for the two things that I learned during this project, the first thing I learned was how to tune a bass by ear, since my phone doesn't have a tuning app, I couldn't download one, and I didn't always have access to Andre's phone, Ashok's phone, or Nathan's phone. The second thing I learned was that I'm pretty good at fingering an electric bass, without having to play it, and I also learned how to make electromagnets of varying strengths.
Frequency- How many waves pass or are created in a certain period of time: measured in Hertz.
Wavelength- Length of the wave or distance from crest to crest: measured in meters.
Period- The amount of time it takes to complete one complete cycle of waves or vibrations: measured in seconds.
Wave speed- The velocity of the wave: measured in meters per seconds.
Amplitude- The displacement of the wave from equilibrium to the crest or trough: measured in meters.
Electromagnet- A type of magnet in which the magnetic field is produced by an electric current running through something such as copper wire. In this case, the electromagnet was created by the copper wire coiled around the screws of the pickup, which was connected to the bass amp.
Reflection- In my opinion, our group blazed through this project in virtually all aspects of this projects, with the glaring exception of the electronic bass, and we had a pretty fun time making each of these instruments without getting too lazy. For once, the divide-and-conquer tactic actually worked quite effectively, with each group member taking responsibility of their own instrument and delivering fully on their behalf. I think our biggest peak was how well we worked together as a group, even though we were relatively independent of one another. What I mean by that is everyone delivered on their obligation, and at times when one person needed help on their portion of the project or the justification, then another person in our group would go to help them. That leads me to our first pit, though, which was that we didn't really know much about anyone else's instrument, except for how the notes correspond to the wavelengths, which was something that we didn't have to worry about since we had the Internet. Our second peak is actually closely related to our first pit, in that we all knew almost everything there was to know about our individual instrument, and I think that the knowledge that we had was clearly demonstrated in our presentation. For example, I could have asked Andre about anything regarding the "recorder", and he would have given me an accurate, correct response, and the same goes for Nathan and Ashok. Our other pit, though, was the fact that we were so concerned about the aesthetics of the bass that we really lost track of time for the completion of the instrument, and I ended up tuning our bass right before we had to give our presentation. As for the two things that I learned during this project, the first thing I learned was how to tune a bass by ear, since my phone doesn't have a tuning app, I couldn't download one, and I didn't always have access to Andre's phone, Ashok's phone, or Nathan's phone. The second thing I learned was that I'm pretty good at fingering an electric bass, without having to play it, and I also learned how to make electromagnets of varying strengths.