This article describes the Circular Sound loudspeaker models in detail. We will dive into the technical specifications and also go into detail on how you can build your own.
Table of Contents
The Circular Sound Process
All Circular Sound products rely on a circular flow of materials. There are two paths to obtaining circularity, but they are not mutually exclusive:
- Biological cycle: Using bio-based and bio-degradable enclosure materials.
- Technical cycle: Remanufacturing from old components.
The biological cycle means using bio-materials such as UPM Formi 3D, BrightPlus BrightBio, and Sulapac Flow. Our mono-material design principle allows easy recycling of the bio-materials at end-of-life.
The technical cycle means we disassemble old loudspeakers, inspect and measure the components and use them in a new product. This is called remanufacturing. The components typically have a decade or more of life remaining, but the old product they were in was no longer wanted by users.
We take sound quality very seriously and often this means only woofers can be reused, while wideband transducers need to be of virgin origin. Nevertheless, the majority of the mass resides in the woofers and enclosure, and therefore the recycled fraction of Circular Sound loudspeakers is 70-80%. You can read more about the circular economy and environmental impact in our blog.
Circular Sound Eikosa
The Circular Sound Eikosa gets its name from the Greek word eikosáedron referring to the 20-faced polyhedron. It’s a Bluetooth loudspeaker that uses upcycled woofers for bass frequencies and a virgin wideband transducer for producing mids and highs. The enclosure is 3D printed from a PLA-based polymer. Each Eikosa is slightly different on the inside depending on the old components used, but thanks to our acoustic design, the low-frequency reproduction varies very little from unit to unit. Besides, the user can adjust the bass tuning and level of the bass frequencies based on personal preference and listening space. You can order an assembled Eikosa by backing our crowdfunding campaign.
| Model | Eikosa |
| Size | 240 mm diameter |
| Weight | ~4 kg |
| Shape | Regular icosahedron |
| Material | Modified PLA |
| Amplifier | 2×30 W |
| Inputs | Bluetooth 5.0 |
| Power supply | 19 V laptop charger |
| Wide-band driver | 3″ BMR |
| Woofers | Upcycled dual 4-6″ |
| Frequency response | 60-20000 Hz (+-3 dB) |
Circular Sound Sfaira (Pair)
Sfaira means sphere in Greek and refers to the shape of the enclosure. The spherical shape has many benefits in loudspeakers. It is made by 3D printing Sulapac Flow material, which is a bio-based and bio-degradable wood-filled plastic. The Sfaira is intended to be used as a stereo pair and supported by a subwoofer, such as the CS-012, if required.
Circular Sound CS-012 Subwoofer
The Circular Sound CS-012 is the first loudspeaker design in the Circular Sound line-up. The donor components come from an old Yamaha YST-SW012 bass-reflex subwoofer, which you can find second-hand for about 50€. Additive manufacturing was used to produce a smaller, sealed enclosure loudspeaker. The material used in the prototype is a bio-based material produced by BrightPlus. It has a natural dye made from woad by Natural Indigo Finland.
The original Yamaha loudspeaker is designed to be used as a single subwoofer unit placed somewhere on the floor out of sight. The new product, on the other hand, is designed to be used in a stereo configuration (2 pcs) and placed under the main speakers. It serves a different function compared to the original product, but no new materials need to be consumed. We are not injecting a new product made from virgin materials into the economy. Instead, we are taking two old ones out and replacing them with one value-added product. This is what Circular Sound is about. You don’t have to wait for distributors to bring sustainable products to your local market. You can start making these today. The files are shared for free under a Creative Commons license on Thingiverse.
