Thanks for the reply’s chaps, ok because it’s a bit tough going here , i was selling the sub to get us over a bad patch and buy something next year but my great wife has said , we will manage , I can not afford another monolith probably ever, but I do need 2 subs now, and it’s my only option to sell this one and some speakers and try to buy 2 smaller sealed subs ,room is 13x13 feet and I don’t listen loud -30 is enough , the problem I’m facing no one wants a sub with no warranty even though I bought it new from a private seller , if svs sb is better than the bk I would go for those. , thanks again