Alpine S-S40 coaxial speakers (100 mm).

Alpine S-S40 2-joslu koaksiāla akustika 4" (100 mm).

The S-Series delivers amazingly high performance for this class of speaker. 
They boast the world’s first use of a CFRP diaphragm (Carbon Fiber Reinforced Plastic), which has the ideal balance of hardness and light-weight, for extremely clean and accurate sound. 
They also feature a larger voice coil than previous types for higher driving power, and the same HAMR surround as used on the X-Series.