Canton Ergo 80 DC's... with issues.

[Quilope]

I just picked up a pair of Canton Ergo 80 DC's from a thrift store. I brought them home, hooked them up, and one seems to be having some issues. The other one seems to be working in all respects. The dysfunctional one sounds really muddy -- the tweeter doesn't seem to be working at all, and the woofers sound weak.

I was thinking to try swapping the tweeters to see if it's a driver problem. All the internal connections are soldered, not clips, so this will take a bit of doing. Would anyone happen to know an easier way? These speakers were manufactured in the early 90's from what I can tell, so maybe it's the caps?

 

[Quilope]

Also, there is some mystery for me with this pair of speakers: the impedance rating on the rear of the cabs is a little confusing. They are rated for "4... 8 ohms." I'm hoping someone out there can shed some light on this. In my experience speakers/amps are rated for either 8, 4, and in some cases 6 ohms.

I just want to try not to damage any gear, if I can possibly help it.