Hertz DCX 690.3 coaxial speakers (164x235 mm).

Hertz DCX 690.3 (DIECI series) 3-Way Coaxial Speakers 6"x9" (164x235 mm).

An authentic 3-way coax capable of reproducing a wide frequency spectrum. 
The DCX 690.3 car audio coaxials uses an oversized magnetic group, 
TPU (Thermoplastic polyurethane) surround, a 60 mm diameter midrange and a PEI dome tweeter. 
The result is linearity, wide dispersion and extra-ordinary efficiency not found in traditional coax components. 
An involving, emotional sound, even at high SPL levels.