Can speakers be tested?

Of course.Take them to a local speaker tech and he will pass a number of sonic tones at various frequencies to see if they are performing up to spec.This will take just a few minutes and you will have your answer.

Sunlight(UV) does not degrade Mylar, BUT will deteriorate the glue, holding the wires to the older models. Magnepan mentioned that fact in their User Manuals, and cautioned against placing them in sunlight. If that(glue failure) is the case with your speakers; you'll hear them noticeably rattling during play. If not(as mentioned by the first respondent); yout ears have probably just acclimated to the sound of your other speakers.

Uh Oh ZD542...Did you hear that car door slam??? It's Elizabeth, I would start running if I were you. :o)

Telescope_trade,

You may be on to something. She's really going to be upset if she slams one of my doors. My Magnepan's sounded so bad I ended up using them as doors. I didn't know what else to do with them. (To their credit, those speakers are a lot heaver than they look in the pictures.)

Rodman: You nailed it, they rattle. So assuming the glue has come unglued, what can be done about it? They're an older model MG 1.6 (fronts) MG CC2 (center) and I think they're obsolete.

Even if they could be repaired, would it be worth it?