Hi ya; I just found this 550 in my storage and decided to give it life. First I open it up clean it with with a sponge with soap and water then dry it all up gave it a good tuner cleaner I then replace the original woofer that was super dryed to it cracking and breaking up paper so I replace it with a 10 inch Foster woofer and chrome capped the original midrange then put it back togethter and whalla: It sounds stuning like a shelf sytem, I also replaced the fuse to a crytal new one. I love it.