MTX Audio TX4 Series 6" x 9" Coaxial Speakers - TX469C Car Amplifier This not only advantageous as

This not only advantageous as it more easily connects to the spider but it also increases the surface diameter of the cone

Recommended Amp Power (RMS) 100 - 200 Frequency Response 24Hz - 160Hz Impedance 4Ω Sensitivity 86

Review from Car&Hifi Magazine in Europe:

2 ohms: 400 watts x 1 chan

or even better our high-end RFL4120 amplifier

MTX Audio TX4 Series 6" x 9" Coaxial Speakers - TX469C Car Amplifier This not only advantageous asThe MTX TX469C speakers shine with their exceptional construction, sound quality, efficiency, including the size of their magnet. They do an incredible job in the original locations of most vehicles. The softness and force with which they reproduce the best recordings is exceptional. The semi pressed paper membrane covered with crystals and silver is musical and clear. The oversized magnetic structure ensures an astounding dynamic and power handling.