Commentary
A woofer system using the largest woofer unit of Diatone developed in 1980.
The unit is equipped with PW 1600 which is a 160 cm cone type woofer.
A honeycomb diaphragm is used for the diaphragm. Aluminum alloy is used for the honeycomb core and CFRP (carbon fiber reinforced plastic) is used for the skin material to realize weight reduction. The weight of the diaphragm is reduced to 3 kg even though it is a super large woofer.
We have also adopted a field coil for the magnetic circuit. At the design stage, when calculated using permanent magnets, the weight exceeds 800 kg even if a strong magnet is used. Therefore, we have decided to use a field coil to reduce the weight. This coil uses electric wires for train motors, and the field coil alone weighs 400 kg.
A high heat-resistant bobbin is used for the voice coil to achieve high input resistance.
Since the frame cannot be cast as a single unit, four parts are assembled with bolts. This unit weighs 600 kg as a single unit.
The enclosure uses a bass-reflex system and is made of a steel balk covered with wood.
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