6x9 bass

I have a set of REF-9630CX 6x9s that a shop installed in my front doors and and they make zero "bass".
I have a hard time believing a 6x9 isn't going to push air. my stock boss system made these things look like a joke.
So I went to the amp (lc-600i) and set the cross over much lower and those things MOVE air great but start to distort like crazy. Can that be cured by changing the speaker cross over setting? Or is that not how it works?

You don’t need two posts on the same thing, it just gets confusing and messy