a 3 inch voice coil should do it...but i am open to suggestions....i already have a form made up for vacum forming the star shape cone...lol it was for a different project thought i might be able to use it on this one ... i have found triangles,hexagons,octagons, ovals and squares...by my count that make 5 other shape, than a circle and i am sure that they were told that there was a reason that speakers are round....if anything i will have a one of a kind shaped subwoofer to run.... And i am about being a one of a kind person... ty for the websites that you have shared they are exactly what i am looking for....when i get the basket and motor made and attached ill post a pic...