Hello All, Need opinions on number of Buttkicker LFE’s for a 20x13x9 dedicated. I plan to mount them under the house, in the crawl space, on the floor joists, directly beneath the front row couch. I was thinking of just two with their BKA1000 amp. Mounting them in the couch would not be practical in this case and I’ve read it’s less likely to be localized mounting this way. Is this enough to feel anything with dual svs 20-39's running? Are these junk, or a gimmick? Do they just buzz your back end or do they feel “bassy?” Any opinions would be greatly appreciated before I spend 600 bucks on two LFE’s and the amp.