[varjag]

There is no way to sort out speaker driver rejects into 1st, 2nd and whatever category. If a sample has quality issue, it is likely to deteriorate further in use rapidly.

Lower quality speakers are not rejects of high quality speakers, they are just cheaper designs.

As to the mold, the holes there require no tolerances, they are there just to avoid air cushion behind the driver and serve no other purpose. Similarly, a foam pad is a rough hack to reduce its effectiveness, driving the speaker's response down. Do you really feel like this foam cut is some precision fix to tolerances problem?