I had very good success putting new foam surrounds on four Rodgers 12" woofers. Speakersworks.com on their web site shows you how to measure the surround dimensions accurately. You need to measure the inside and outside diameter of the surround, and the outside diameter of the speaker cone. I found a perfect fit, even though it was for a brand I didn't recognize.
https://www.speakerworks.com/foam-surro ... g-s/63.htmThey list special sizes for subwoofers which have large rolls for extra travel.
Alternatively, you can try Simply Speakers which lists a plethora of brand-specific kits.
https://www.simplyspeakers.com/speaker- ... -kits.htmlAs Ed mentioned, careful gluing is the key. Do not try to glue both the inner and outer parts of the new surround at the same time. I found that the latex-type glue takes a long time to set on the frame. I believe I glued the surround to the frame first. You may have to press down around the circumference repeatedly for a half hour while the glue sets up, until the surround remains in place without lifting. As per Ed, the cone does self-centre, so once the surround is glued to the frame and has set overnight, you can apply the glue to the edge which attaches to the cone, and it will set very quickly.
Also key to a good job is careful removal of the old surround, Peel it away very carefully from the cone. Tease the inner edge, and then pull gently. If necessary use a razor knife on the speaker frame if the foam bits won't come off.
Ray