17. Project Development

Spinning speaker

WHAT TASKS HAVE BEEN COMPLETED?

I have already designed, cut, and soldered the LM386 amplifier board. In addition to that, I have also completed the design of various components that are essential for the project. The 3D printing of these parts, including the rotating horn, is currently in progress. I have designed the circuit board with a transistor to control the speed of the DC motor.

WHAT TASKS REMAIN?

I still need to take measurements of the 3D-printed parts and the boards so that I can design and cut the speaker enclosure from MDF. This enclosure will provide a solid housing for the components and help optimize the acoustic performance of the speaker system. Additionally, I need to conduct tests with the motor and the spinning horn. These tests are essential to ensure that the motor provides adequate speed and force to rotate the horn effectively. By testing the motor and horn together, I can verify their compatibility and performance in producing the desired sound effects, such as those related to the Doppler effect. Once I have completed these measurements and tests, I will be able to proceed with the final assembly of the speaker system. This involves integrating all components into the MDF enclosure and fine-tuning the setup to achieve optimal sound quality and performance. These steps are crucial in ensuring that the finished speaker system meets the project's requirements and functions reliably in its intended application.

WHAT HAS WORKED? WHAT HASN'T?

So far, everything related to the electronics has worked as expected. The circuits have been assembled correctly, and all components are functioning as intended. However, the final test involves the practical application of these electronics with the horn to evaluate the sound quality and performance.
I still need to conduct tests with the horn to see how it sounds when connected to the amplifier and powered by the motor. This step is crucial to ensure that the sound output meets the desired specifications, such as volume, clarity, and any specific audio effects like the Doppler effect. Adjustments may be necessary to fine-tune the amplifier settings or the positioning of the horn to optimize sound projection and quality.
Once these tests are completed successfully, the entire system will be ready for its intended application or demonstration. This practical testing phase ensures that both the electronic components and the mechanical parts, like the horn, work harmoniously together to achieve the desired audio output.

WHAT QUESTIONS NEED TO BE RESOLVED?

Does the DC motor provide the necessary force to rotate the horn?
Does the audio output from the horn change the sound quality?

WHAT WILL HAPPEN WHEN?

The motor, providing the necessary speed and force to move the horn, will cause it to rotate. As the horn rotates, the sound it produces will exhibit the Doppler effect. This effect occurs because the frequency of the sound waves changes relative to the listener as the source (the horn) moves. When the horn approaches the listener, the sound waves are compressed, resulting in a higher frequency (higher pitch). Conversely, as the horn moves away, the sound waves are stretched, resulting in a lower frequency (lower pitch). This variation in frequency creates the characteristic change in pitch observed with moving sound sources, demonstrating the Doppler effect.

WHAT HAVE YOU LEARNED?

There are many ways to use the LM386 amplifier, each with its own advantages and limitations depending on the specific requirements of the application. While some configurations might enhance audio quality in low-power applications like portable speakers, others might prioritize efficiency and power output for driving larger speakers or audio systems. It's crucial to experiment with various configurations and applications of the amplifier to determine which one aligns best with the project's objectives. Factors such as input impedance, gain settings, power supply considerations, and overall circuit design play significant roles in optimizing the performance of the LM386 amplifier for different purposes. Through thorough exploration and testing, the most effective and suitable configuration can be identified to achieve optimal results in any given application.