The Arizona STEM �Acceleration Project

2025

The Science of Speakers

​

A 8th-12th STEM Lesson

​

Students will build a working speaker from simple and low cost materials. They will then apply the science concept they’ve learned to explain how the speaker works. Lastly, they will develop their engineering skills as they modify and improve their design.

David Wirth

The Arizona STEM Acceleration Project

Notes for teachers

Many students enjoy listening to music, making it the perfect hook for an engaging STEM lab. In this activity, students build their own working speaker to play music, combining creativity with hands-on learning. With simple, low-cost materials, this project connects key STEM concepts such as electricity, magnetism, sound, and engineering in a fun and memorable way. The biggest challenge for the instructor will be finding a source to produce the electrical signal for the sound.

But this can be easily remedied by using an old audio source like the one below that can be purchased at a thrift store.

​

​

List of Materials

transparent tape

disposable cup

small neodymium magnet

26 gauge* or higher enamel coated wire

Old radio with speaker outputs

alligator clips

​

The higher gauge keeps the circuit from shorting out and causing disruptions with the sound.

​

Standards

Physical Science Standards:

• HS.P1U1.3 – Develop and use models to illustrate the interactions between electric and magnetic fields and how they can be used to generate or transmit energy.��
• HS.P4U1.3 – Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model.� The speaker project naturally prompts questions about how sound and electrical energy travel.�
• HS.P4U3.1 – Design, evaluate, and refine a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and tradeoff considerations.� The speaker build requires iterative engineering, design decisions, and troubleshooting.�

Engineering Standards:

• HS.E1U1.1 – Analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants.� Students can frame their speaker design around access to low-cost technology.�

​

• ​
• ​

8th Grade Science Standards:

​

8.P1U1.3 – Plan and carry out investigations to determine how electric and magnetic forces interact.� Students see the interplay of electricity and magnetism in the speaker design.�

8.P4U1.3 – Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.� The movement of the speaker cone and sound waves can be used to model wave behavior.�

8.P4U1.4 – Analyze and interpret data to describe the relationship between the amplitude and energy of a wave.

​

Objectives:

The objective for this activity is for the students to build a working speaker from given instruction.

The students will apply their knowledge of electricity and magnetism to explain how the speaker works.

The students will use engineering principles to modify their speaker to produce a “better” sound.

Agenda

Day 1:

Introduce the activity and have students build a working speaker from a given design. Have students answer questions related to how the speaker works.

Day 2:

Have students work in groups to discuss and create a whiteboard to explain how the speaker works. Have students present their whiteboards to each other.

Day 3 & 4:

Challenge the students to create a speaker with either a “better” sound, one with a louder volume or headphone type speakers.

Students will write a report detailing their design and explaining the concepts they learned.

You’ve listened to speakers many times. How many different uses for speakers can you name?

Time to build a working speaker

​

​

You will build a speaker using the following materials.

• Plastic or paper cup
• 50 cm of enamel coated wire
• small amount of tape
• a few magnets

​

Building a Speaker - Instructions

• Place the magnet on top of the cup.
• Loop the coil about 20 times - slighter larger than magnet. Place it on top of the magnet.
• Sand the enamel off the ends of the wire.
• Bring your speaker to your teacher and have them play it.

​

​

Hands-on Activity Instructions

Have students work in groups of 3-4 on this project. The speaker does not take very long to build and is relatively basic. The biggest challenge will be finding a way to play them. There are several techniques you can use.

​

• Find an old radio with speaker outputs.

​

​

​

​

​

You can plug the homemade speaker directly into the radio outputs You may have to turn down the volume if the speaker cuts out. You can find old radios at thrift stores.

** Many youtube videos can be found on how to build these types of speakers.

• Find a bluetooth amplifier. You can connect the speaker directly to the outputs.

​

​

​

​

​

​

​

​

​

​

​

​

• You can take the audio jack from an old set of headphones and connect the headphone directly to this jack and plug that into a source. Unfortunately cell phones these days rarely have audio jacks.

​

​

​

Whiteboard

Work with your group to create a whiteboard presentation that explains how your speaker works. Address the following questions:

​

1. What is the role of the wire and magnet?� How do they work together to produce sound?�
2. What causes the vibration?�
3. What is the purpose of the cup?�
4. What changes could be made to increase the volume of the speaker?

​

Teacher notes

Here are some sample whiteboards, both good and bad.

​

​

​

Engineer a speaker

Now that you’ve learned about how a speaker works, it’s time for you to improve the design of the previous speaker. Your goal is to build a speaker which has one of the following qualities:

​

• Built for loudness
• Built for quality
• Build speakers to be used as headphones.

​

You will be given common materials to use such as: paper plates, plastic cups, paper cups, cotton balls, magnets, wires, construction paper, tape, paper clips, cardboard, etc. You are free to bring in your own materials that can be used to construct your working speaker. You will also complete a report detailing the work you have done and the science concepts you’ve learned during this process.

Assessment

Have students complete this exit ticket to assess understanding.

​

Click here for the exit ticket.

Speakers my students created

Differentiation

Remediation

Extension/Enrichment

There are many youtube videos that give instructions on how to build a speaker and the science concepts behind how they work.

​

Check in with students throughout the lab activity.

​

​

Have students take apart a speaker or headphones and show its working parts.

​

Have students find a relationship between two variables with the speakers. For example, find the relationship between the volume of the produced sound and the number of coils.

​

​