Bowers & Wilkins introduced Kevlar as a high-quality material to make speaker cones in 1974. Typical of their work is the 801, which many audiophiles feel began the modern era of high-end speaker design. Woofer, midrange and tweeter are isolated in separate chambers to produce sound of unheard-of-realism. The 801 is the de facto standard studio monitor in classical studios, and is highly regarded as an audiophile loudspeaker. They're still being made.