At 50k the I doubt the quality of the sub or the difference it could additionally add to the already existing setup. REL is good but very expensive...good for music. But for movies, general consensus in most of the forum talk is svs...svs sb1000 is pretty near your budget I guess. Pb1000 is slightly more pricey...i have titinus too, but not a big botheration so far...i own sb3000 (svs) and sb16...their app helps tune subwoofer in ways that cant be done by many other subwoofers...its too good to be true and the performance is tooooo good!!