Could use some help determining the best sub for my application.

Here's what I have that I can't change

500rms @2ohm alpine amp
1.25cf box in dimensions of ID:11wx11hx21L

Having a hard time finding subs that fit those parameters
Im in between spl and sq as I listen to everything but prefer more towards spl.

Prefer ported over sealed.

Seems like every time I find a sub/subs setup I like, it's either out of my power range or requires more cf volume ported.

In today's subs It looks like size plays a small role. I've seen some impressive results with small subs. Even 6.5" subs

So far I'm considering 2- sundown EV8 v5 but they'll be on the low side of box volume

Just don't know much about quality subs
American bass still decent? Skar? Dayton? Half these guys have all sold out over the years and don't know who's still making decent stuff.

 

What size opening is in the box and is it ported already?

 

I ended up building a center console box. It's not finished yet, still going to get a dark gray leather top with cup holder. armrest and shallow tray for phone.

It's a down firing box that finished with 1.5cf (with port and subs deducted) ported and tuned to 32hz.
I just threw some diamond audio CM310D4 subs that I had laying around in there and I'm pretty impressed considering their wired at 4ohms because my amp's not stable at 1ohm and their only getting 300watts to both. They were in a sealed box their whole life and now to hear them in this box just blows me away. Sunglasses bouncing on the dash a even some door flexing. Can't wait to put some better quality subs in there

Primed and painted flat black with rustoleum furniture paint.