Titanium Nickel Alloy Vapor-deposition Injection-molded Pearl-mica Polypropylene Cone: Uniform cone thickness; excellent internal dampening. Deep powerful bass; smooth midrange response; low distortion. Titanium Nickel Composite Midrange (HED-1683/1693) Low mass diaphragm. Natural sounding vocals; superior transient response. Titanium Nickel Composite 1/2" Balanced Dome Tweeter: Extended high frequency response; wide dispersion. Outstanding high frequency detail up to 22 kHz. Built-in Passive Crossover Effectively distributes frequency bands to appropriate drivers. Improved sonic clarity and overall efficiency. Low Profile Tweeter/Mid Easily fits behind factory grilles. Fast drop-in installation. Direct Factory Replacement Adapts easily to factory cutouts. High-end component sound without major modification; saves install time.