NS-1000M

Although being hard, rigid and lightweight made it the perfect material, beryllium was said to be too difficult to process — until Yamaha developed a beryllium diaphragm.
This speaker system was the first to employ a diaphragm of pure beryllium.
Wide-ranging accurate tones and the openness and clarity of mid and high frequencies evoked a reaction around the world when it first went on sale.
In 1976 Swedish national broadcaster Sveriges Television chose the NS-1000M as its official monitor speaker, as it commanded respect as a professional monitor. Over 23 years up to 1997, over 200,000 units of this longtime bestseller were sold.