SW-120 differences?

Driver_King

So today I started to take out my passive radiators to replace the Poly-switches and noticed that one of my passive radiators has a different surround than the other. It's not very noticeable on the outside but once you move it around, the difference is apparent. The passive radiator that seems to be bothering me now is the right passive radiator. It has a surround that seems shallower than the left PR. I'm thinking this may be the reason that the right speaker bottoms out much faster than the left speaker. Any thoughts?