Advent Speaker Repair?

I recently acquired a pair of the Advent big Kloss speakers with the 'famous' orange tweeters that are in excellent shape and a couple of Radio Shack 12" woofers that suck.  The back features a switch where the wires enter that offers some 'power' differential.  Can anyone tell me more about these speakers and especially the switch thing?  They do nothing when I click the switch so I figure the filters must be shot.  Again, I do not know what to expect either.  Please fill me in?  
Thanks to bigkids for this referal info.
Bub
I would start a new thread but can see how to do that.

See if Bill can help you out very fair and reasonable.

Millersound
Bill
1422 Taylor Road
Lansdale PA 19446
215 412-7700

Happy Listening

Advent is long gone. I do not know of any "Official" repair shops but you can do a web search for businesses that offer repairs to the drivers (foam surround, etc.) The foam kits are readily available along with people who will do it for you. Be careful though, some of this replacement stuff changes the sound somewhat.
Might try, "Just Speakers." Also, check on Ebay. I just picked up a pair of 8" woofers for a small pair of the Advent II's. I bought a set of what were reported to be "Equivalent to the original" woofers from Just Speakers for my "New Advent" speakers. Sound and look the same.
Tweeters are readily available on Ebay.

Not in business. Bought and sold several times. I have older pair of Legacy's that I had refoamed for approximately $50.00 at Simply Speakers out of Florida. DO a web search for them. Also came across an outfit called Layne Audio that has numerous replacement parts and offers repairs. Good luck.