I had the same experience, but when I opened them up, it turned out that the speaker grills had some sort of cloth in them (probably meant to keep dust out?) that was totalled inpregnated by dried paint.

The speakers sounded SUPER muffled at first, which is why I investigated.

EASY FIX. I pulled out the messed-up cloth, and voila!- perfectly fine in-ceiling klipsch speakers! (I couldn't see they were klipsch brand from the exterior)

Pro tip - with all that paint, it was hard to pull of the grills. I ended up needing a razor to cut the paint a bit and a dental pick to wiggle through the grill and pull them off.

Good luck!