I'm after a sub shortly. I have seen a rel q100e in excellent condition in a local shop. Is this roughly the right price for one of these subs? Also, i've done a search on here but there seems to be a bit of a mixed opinion as to how low these go. I've demoed a q150 before and it was no better than my main speakers which go surprisingly low for what they are (next to a wall). They shake the sofa slightly which was all the Q150 did and no more. Will the q100 show a better result??