The size of my cone and rubber surround is 93 mm. The rubber surround itself appears to be quite decently sized, it is meant for about 3/4inch Excursion. If you want to look it up, it is a Drok 4" 40watt 4ohm speaker on amazon.
I have two 4in 40 watt 4 ohm subwoofers with a amplifier that has 50 watts per Channel. I was wanting to build a base flex ported box. Can anyone help out because I'm not 100% sure how to do this... if there are any audio Geeks out there it would be wonderful to hit me up!