I just refoamed my Ref Fours last month using a kit sold on eBay. I found a (Florida-based) seller who had a 4-piece kit to refoam both the woofers and mids on this speaker. If you do a search for "Infinity Reference Four foam" on eBay, one or two options should show up. The kit I bought worked perfectly, including the right kind of glue for the IMG drivers and no need to trim the midrange foam.
BTW, I used the battery approach to center the drivers so I wouldn't have to remove the inverted dust caps for shimming. By far the hardest part of the job was removing the plastic trim rings that are glued to the driver baskets and hold the foam in place. The best way to do this is use a hair dryer or heat gun to melt the glue that holds the trim rings in place and then gently pry them off with a screwdriver. If the glue isn't melted first, it is really easy to crack the plastic rings (there are some very helpful AK threads about this).
My Fours were a thrift store purchase as well, but I paid quite a bit more than either of you ($30 for the pair). I think the only reason they made it to the floor is because one of the EMIT-R tweeters was completely blown (both the tweeter diaphragm and the thermal breaker were overloaded and had open circuits). After repairing that EMIT and refoaming all of the IMG drivers as a preventive measure, these are now serving as my main speakers in a small listening room. Despite how modest the woofer (especially) and midrange drivers are, they perform surprisingly well. I think they have been enough to get me addicted to EMITs and the Infinity house sound. Since I understand that these are pretty low on the Infinity totem pole, I will probably keep an eye out for better Infinity models in the future. Any thoughts on what would be a noticeable step up without breaking the bank?
