i'm looking for a single sub preferably a 15". my budget is less than or around $600. i will be able to spend about $700 for an amp to power it. the sub will be used as a Daily driver. i want one that gets loud but still sound halfway decent. about 65% SPL and 35% SQ.

so far i have been thinking of:
15" FI BTL
15" FI Q
15" AQ HD3

any other suggestions would be helpful thanx.