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Circular Economy of Loudspeakers – Reducing Waste and Creating Value

Circular economy practices will transform the loudspeaker industry by reducing waste and emissions while increasing value and sustainability.

Introduction to circular economy

Circular economy is a model of production and consumption that prioritizes resource efficiency and waste reduction. It involves designing products with durability and repairability in mind, reusing and refurbishing materials and products, and recycling materials at the end of their useful life. The goal is to keep resources in use for as long as possible and minimize environmental impacts. Currently, only 7.2% of the materials we use circulate back into the economy 1. This number needs to increase in all industries, including the loudspeaker industry, in order to reach the Sustainable Development Goals, more specifically SDG 12.5 2:

“By 2030, substantially reduce waste generation through prevention, reduction, recycling, and reuse”

The current linear model of loudspeaker production

The global loudspeaker market size is anticipated to reach USD 8.48 billion by 20253. Its effect on the circularity gap can not be ignored. Most manufacturers using virgin materials attempt to mitigate their environmental impact by focusing on long lifespans by:

  • Producing long-lasting products
  • Offering spare parts and warranty repairs
  • Facilitating a second-hand market for pre-owned loudspeakers.

However, it does not matter if a product can be used forever if nobody wants it anymore. Our research shows that having a specific need is the main reason for loudspeaker buyers not using the second-hand market. This is confirmed by studying the thousands of near-zero-priced loudspeaker listings in online marketplaces. There is low demand and a high supply of old but fully functional loudspeakers. The current economy has no end-of-life solution.

Old loudspeakers with negligible market value.

The importance of loudspeaker magnets

Not having an end-of-life solution for old loudspeakers is especially problematic due to rare-earth elements found in the magnets of loudspeaker transducers. Rare-earth elements are essential for manufacturing permanent magnets. Permanent magnets are critical components in most decarbonisation technologies4 .

Lithium and rare earths will soon be more important than oil and gas. Our demand for rare earths alone will increase fivefold by 2030.

Ursula von der Leyen, President of the EU commission5

The EU imports 98% of its magnets from China and less than 1% is recycled6. Relying on China poses a geopolitical and supply chain risk. China has a history of export restrictions and weaponisation of REEs in trade wars7. Recycling is not commercially viable due to the high cost of manual separation of magnets and the relatively low price of the raw material itself8.

Loudspeaker transducers have large magnets containing precious materials.

The circular economy approaches to loudspeakers

The circular economy of loudspeakers can be described with the help of the 7Rs.

  1. Rethink: Use fewer components and eco-friendly materials, combine functions, or make the product easy to disassemble and recycle.
  2. Reduce: Spend less material and energy. Generate less waste.
  3. Reuse: Sell in the second-hand market.
  4. Repair: Fix broken loudspeakers by re-coning transducers, replacing components, and refurbishing the enclosure.
  5. Remanufacture: Disassemble old loudspeakers and use the materials to make a new product.
  6. Recycle: Use raw materials, such as plastic and metal, again.
  7. Recover: Burn the enclosure for energy.

All of the approaches are a step forward from the current linear economy. The first two (Rethink and Reduce) are effective since they occur already at the design stage. However, they still rely on virgin materials and do nothing about the current levels of waste. The last two (Recycle and Recover) are not recommended, because they do not preserve added value and hardly generate any jobs or social well-being. Reuse and Repair are great if there still is demand for that product. Remanufacturing allows for meeting new user needs using existing materials. An example of remanufacturing is the RD Physics Circular Sound loudspeakers.

Circular economy loudspeaker
A new loudspeaker using components from old loudspeakers.

Benefits of circular economy

The benefits of a circular economy include reducing the extraction of virgin materials, reducing greenhouse gas emissions, creating new job opportunities, and improving the resilience of the economy. It also has the potential to create a more sustainable and profitable industry, reduce resource costs, and improve social and environmental outcomes. By introducing a circular economy for the loudspeaker transducers specifically, we can achieve:

  • Independence of imported magnets
  • Reliable supply chains
  • Reduced need to mine rare-earth elements
  • Preservation of added value in existing products
  • Utilization of electronics waste

Life-cycle impact assessment of loudspeakers

Life-cycle analysis can be used to quantify the impact of the circular economy of loudspeakers. The majority of the impact comes from magnets and the chemical processing of the rare-earth elements in them. For example, the Circular Sound Eikosa loudspeaker contains approximately one kilogram of magnets in the upcycled transducers it uses. The life-cycle impact assessment of 1 kg of magnet reported here is an average of several sources reported in two studies 9,10.

Impact categoryQuantityUnit
Global warming69kg CO2 eq.
Acidification0.63mol H+ eq.
Eutrophication (freshwater)0.015kg P eq.
Eutrophication (marine)0.09kg N eq.
Eutrophication (terrestrial)1.26mol N eq.
Ecotoxicity (aquatic)331CTUe
Human toxicity (carcinogenic)3.4CTUh
Ozone depletion4.2*10-6 kg CFC-11 eq.
Particulate matter0.12kg PM2.5 eq.
Ionizing radiation4.19kBq U235 eq.
Water consumption0.63m3
Impact per kilogram of rare-earth permanent magnet

Conclusions

All industries need to transform into a circular economy in order to close the circularity gap and reach the Sustainable Development Goals. The current loudspeaker industry operates in a linear fashion and trusts that a long product life will mitigate environmental impact. However, there is no end-of-life solution available and precious raw materials found in the loudspeaker magnets end up in landfills.

Various circular economy solutions exist. Minimizing material use and swapping one material for another is an incremental improvement, but still involves virgin materials. Repairing and relying on a second-hand market assumes there is still a demand for the old product. Recycling the raw materials destroys the added value of the product and is not economically viable due to manual disassembly steps. Remanufacturing, on the other hand, offers a way to meet new customer needs using components and materials from old products.

Sustainable loudspeaker
A remanufactured loudspeaker 3D printed from bio-based materials and using components from an old subwoofer.

Upcycling old loudspeaker transducers and using them in a new product keeps the magnets in our economy and reduce the need to produce virgin magnets. This has quantifiable environmental impacts, such as avoiding 70 kg of CO2 equivalent in greenhouse gas emission per one kilogram of magnet.


Appendix A: Life-cycle impact assessment categories

Life cycle impact assessment (LCIA) is a tool used to evaluate the environmental impact of products or services across their entire life cycle. To measure these impacts, a variety of impact categories and units can be used. Here are some examples:

  1. Global warming: This impact category measures the amount of greenhouse gases (primarily carbon dioxide) that are emitted over the life cycle of a product or service. The unit used is typically kilograms of carbon dioxide equivalent (kg CO2e).
  2. Acidification: This impact category measures the amount of acidifying substances (such as sulfur dioxide and nitrogen oxides) that are emitted over the life cycle of a product or service. The unit used is typically moles of hydrogen ions (mol H+).
  3. Eutrophication: This impact category measures the amount of nutrients (primarily nitrogen and phosphorus) that are released into the environment and contribute to the growth of algae and other aquatic plants. The unit used is typically moles of phosphate (mol PO43-).
  4. Particulate matter (PM): This impact category measures the amount of fine particulate matter (PM2.5) that is emitted over the life cycle of a product or service. The unit used is typically micrograms of particulate matter per cubic meter (μg/m3).
  5. Ecotoxicity (aquatic): This impact category measures the potential harm that a product or service may cause to ecosystems and their inhabitants. The CTUe (Characterization Factor Toxicity Unit – ecotoxicity) unit is based on converting the amount of a substance emitted during a product’s life cycle into a standardized ecotoxicity value. The ecotoxicity value is expressed in CTUe per kilogram (kg) of the emitted substance. The characterization factor takes into account various parameters such as the chemical properties of the substance, its persistence in the environment, its toxicity to aquatic organisms, and the extent of the area affected by the emissions.
  6. Human toxicity (cancer): This impact category measures the potential harm that a product or service may cause to human health. The human toxicity value is expressed in CTUh per kilogram (kg) of the emitted substance. The characterization factor takes into account various parameters such as the chemical properties of the substance, its toxicity to humans, and the extent and duration of exposure. When the CTUh unit is used to assess cancer risk, it is often expressed as cancer cases per million people per year (cases/million/year), rather than CTUh/kg. The cancer risk is calculated by multiplying the amount of the substance emitted by its cancer potency factor, which represents the likelihood that the substance will cause cancer in humans. The resulting value is then converted into cancer cases using demographic and exposure data.
  7. Ozone depletion potential: The ODP of a substance is determined by comparing its potential to deplete ozone to that of CFC-11. Many ozone-depleting substances, including CFCs, are banned. The use of CFC-11 as a reference substance is only relevant for historical analysis or for assessing the impact of new substances that may have similar properties to CFCs.
  8. Ionizing radiation: It is used to represent the potential harm a substance can cause to human health through exposure to ionizing radiation. The unit kBq U235 represents the activity of uranium-235, which is a measure of the rate at which the material emits ionizing radiation. The unit kBq stands for kiloBecquerel, which is a unit of radioactivity. One kBq corresponds to 1,000 disintegrations per second.
  9. Water consumption: This impact category measures the amount of water used over the life cycle of a product or service. The unit used is typically cubic meters (m3) of water.
  10. Land use: This impact category measures the amount of land required over the life cycle of a product or service. The unit used is typically square meters (m2) of land.

There are many other impact categories that can be used in life cycle assessment, depending on the specific environmental and social impacts of interest.

References

  1. Circle Economy. Circularity Gap Report 2023. https://www.circularity-gap.world/2023
  2. United Nations, Department of Economic and Social Affairs, Sustainable Development. https://sdgs.un.org/goals/goal12
  3. Loudspeaker Market Size, Share & Trends 2018 – 2025. https://www.grandviewresearch.com/industry-analysis/loudspeaker-market
  4. European Union EIT Raw Materials, May 2020. https://eitrawmaterials.eu/wp-content/uploads/2020/04/EIT-RawMaterials-Position-Paper-COVID-19.pdf
  5. Ursula von der Leyen. 2022 State of the Union Address. 14 September 2022. https://ec.europa.eu/commission/presscorner/detail/ov/SPEECH_22_5493
  6. Gauss, R. et al. European Raw Materials Alliance. Rare Earth Magnets and Motors: A European Call for Action. Berlin 2021. https://eit.europa.eu/library/rare-earth-magnets-and-motors-european-call-action
  7. United States Congressional Research Service. Trade Dispute with China and Rare Earth Elements. June 28, 2019. https://crsreports.congress.gov/product/pdf/IF/IF11259
  8. Liang Cong et al. Modeling the Value Recovery of Rare Earth Permanent Magnets at End-of-Life. Procedia CIRP 29 ( 2015 ), pp. 680 – 685. https://doi.org/10.1016/j.procir.2015.02.015
  9. Josefine Marx, Andrea Schreiber, Petra Zapp, and Frank Walachowicz. Comparative Life Cycle Assessment of NdFeB Permanent Magnet Production from Different Rare Earth Deposits. ACS Sustainable Chemistry & Engineering 2018. 6 (5), pp. 5858-5867. doi: 10.1021/acssuschemeng.7b04165
  10. Praneet S. Arshi, Ehsan Vahidi, and Fu Zhao. Behind the Scenes of Clean Energy: The Environmental Footprint of Rare Earth Products. ACS Sustainable Chem. Eng. 2018, 6, 3, pp. 3311–3320. https://doi.org/10.1021/acssuschemeng.7b03484