Lexus is committed to improving the performance its vehicles while simultaneously reducing their environmental impact. One method of achieving this is by pioneering the use of natural materials in new, innovative and intriguing ways.
Bamboo is the latest natural material to be adapted for use within Lexus vehicles. The cane is not only being recognised for its aesthetic qualities, as seen in the optional laminated bamboo trim of the latest GS 450h, but also for its acoustic properties, such as that experienced within the premium sound systems of the CT 200h.
Mainstream speaker diaphragms are usually made from either paper or resin injection moulding. Paper diaphragms, though producing precise sound reproduction over a wide audio range, are relatively weak, offer little resistance to moisture, and require a large number of processes to construct. Fibre-reinforced resin items, on the other hand, are stronger and more reliable but have a limited vocal range.
The idea, therefore, was to use a different material to deliver the clear, natural sound properties of an organic material within a more resilient, resin injection-moulded form.
The perfect material turned out to be bamboo, long used throughout Asia as a durable building material, nutritious food source, and versatile raw product. Additionally, as one of the world’s fastest-growing plants, it only takes about one year to grow to full height — approximately ten times faster than the conifer trees traditionally used to make paper diaphragms.
Bamboo fibres are more durable than other fibres and have an extensive sound range. But integrating them with other materials to produce a complex compound was very difficult. A brand-new, patented extrusion process was therefore devised to uniformly disperse and compound the carbonised bamboo, bamboo fibre and resin needed to injection-mould the diaphragms.
Thanks to this use of bamboo materials, the resin speaker diaphragms in the Lexus CT 200h are moulded to a thickness of just 0.2 to 0.3mm — the thinnest of their kind in the industry. The new composite material is also 10-15% lighter, 20% stiffer and has 10% greater sonic speed than a conventional resin diaphragm.
This industry-first from Lexus and audio partner Panasonic was not pioneered simply to drive down kerb weight, increase percentages, or make less of an impact on the environment. An equally important but less tangible element for the development team was the marked improvement these unique speakers offered in listening pleasure, thanks to clearer, more natural sound reproduction.
The only way to truly appreciate the bamboo-enhanced sound quality of the premium six- or ten-speaker sound systems within the Lexus CT 200h is to listen for yourself. And we encourage you to do so at your local Lexus Centre.