Restore Infinity RS3b - foam around all 4 woofers

Here are two of the best service for this type out there:

http://www.simplyspeakers.com

http://www.millersound.com

Check out Parts-express for their repair speakers section. They have re-foam kits. I've used them and although they cn be tricky, they work. Another trick for foam not too badly damaged is rubber cement. This was actually recommended to me by a technician at Parts-express. Fantastic technical support by phone and on line.

The folks you want to entrust your Infinity woofers to are Watkins Engineering. http://www.watkinsstereo.com/
Very reasonable prices and expert workmanship. They use a material which retains the characteristics of the original foam but lasts longer. I had four woofers redone last summer and they perform flawlessly. Well worth the effort.