REL S510 or S812

In the S series, I'd say you would want the 812 given your requirements.  Two are better than one for two channel, but that gets kinda pricey. 

My SVS sub is a PB12-nsd. It's only a 12 inch, but it's pretty big. It will shake the house. It's ported. 

bjesien

I can make the walls rattle if I want😁

I thought i would give you some context as to why I love the sub.  My speakers are Paradim 120H's which have 3 powered 8" woofers that claim to have an off axis response down to 20hz. They have fantastic bass. ( great speaker) Anyway,  my 812 crossover is set to about 30hz and the volume is only 4 or 5 clicks up.  So it basically just fills put the bottom end and expands the sound stage. If u want to impress the neighbors or buddies with some techno or hip hop, crank it half way and Holly crap!!! Tight and controlled.....Bad Ass.... Im sure there are other great subs out there but that's my 2 cents. 

Good luck

Yes! Thanks for the reply. I somewhat jokingly write these things but there is an undercurrent to music, almost at the atmospheric level, that is great to connect to. I had a pair of Verity Parsifal Anniversary that held this space well. It really takes a $20k plus main to start to create this foundation. 

Reason would say this line has been out for about 4-5 years. Are they clearing the inventory for a new launch? 

No clue buddy.  Even If they are, new isn't always better.  If there's a good deal and you've decided on REL I'd take the plunge.