Well, got hold of some Infinity 552is (4 of them) and went out to my car at lunch time, armed with a philips screw driver, got the cover off for the first speaker, and found that they were held in by 4 Torx screws.....
Bugger..... and Im meant to be going out as soon as I get home wanted to try them out, but aint gonna be able to until sunday now
-Roamer