I borrowed a neighbours old sub for a couple of weeks and it was pretty great, but I think I'm looking for something that puts out sub 20hz.
Have you considered using a
ButtKicker Nothing I’ve used goes that low with as much authority. Use one and you will quickly learn that there is almost nothing out there to reproduce in the under 20Hz range.
If your looking for chest pounding maybe try a
MBM-12 Mid-bass Module I haven’t ever used one but am thinking about trying one to see what it can do in conjunction with a Buttkicker and EP500.