Carbon Fiber, Carbon Fiber, Carbon Fiber!!!! I had a buddy do a comparison test between many different brands of woofers which utilized many material topologies (stuff like kevlar, Polypropolene, etc). He found one thing in common with the carbon fiber varients that he tested: They were much less colored in the upper bass/lower midrange frequency regions, than any of the other materials utilized employed in the the other woofs.(Unless you plan on crossing over your woofer below 100hz, I strongly consider going with a carbon fiber unit). If I recall, the Vifa was deemed the best overall sounding driver.
