Pairs of non-mainstream Subs that have good output sealed????

[mwoehr 1]

So far I know of some mainstream subs that can have decent output sealed like JL Audio or Kicker. I also know the AA Havoc's are supposed to be suprisingly loud sealed, but that's in a much higher power range. What non-mainstream subs in the 500 watt power range have good output sealed. I know the dcon's are great subs, but much better off ported than sealed. I have a friend that wants a pair of 12s or 15s sealed off 500 watts and I'm trying to steer him away from maintream and to run something different than the JL's, RF or Kicker that everyone has around here. I'm just not sure what non-mainstream subs are capable of getting loud sealed. I tried the dcon 12s sealed and didn't like them at all sealed, but ported they are night and day. He'll do up to 1.5 cubes per sub (1.5 cubes with a pound of polyfil in each chamber if he runs 15s). The subs I'm leaning him towards are DC Level 2's, IA 187's, AA Arsenal's or RE SRx's.

[Tirefryr 1,742]

I have a pair of 12" MagV3s that fit that bill perfectly. Hell just one in my truck off 250watts in 1 cube was enough to cause ear pain.