I know with only 5k I should have a bigger box, but this is as big as I can go. Let me know what you think. Goal is to get low (play mostly Decaf and other slowed/modded music) and move some air. Thanks.

 

How do you know you need more than 5Kw?  Unless you have modeled for excursion you have no idea.

 

That (5Kw), as a minimum, is almost more than the drivers are rated for thermally.  Depending on the amp, you could be applying well over the continuous rating of the drivers and cause thermal failure.

 

Again, until you model for excursion, in your chosen alignment, you have no idea how much power you will need to get full, non-distorted, output from your subwoofers.

 

Nothing wrong at all with having all that power, you just need to be careful when using it.