Boss Man 3 Way 4 Inch High Performance Coaxial Car Speaker.They feature piezoelectric tweeter which contains an active element that has been positively charged,

 Piezo speakers are much are less susceptible to overloading. These high-frequency drivers cope better and don't require any crossover.

 They feature a tiny half-inch silk dome Piezoelectric tweeter to effectively deal with high-frequency audio.

 Having separate types of speakers designated to different frequency ranges gives a more natural They produce good resonant sound with reasonable clarity. 

They have excellent circuitry with very low impedance and can be front or rear mounted with relative ease at the convenience of a few standard spade wires

 They make for a remarkably noticeable upgrade to factory installed car speakers, in terms of fidelity.

 The sound, in general, is pretty full range despite the 3-way class.

 They feature proprietary Plus One cone technology allowing them to provide more cone are than any other speaker in their class for unrivalled dispersion.

 Sound.