I have no experience, but someone posted an infinite baffle set up the other day with four 18" subs. It was completely recessed into the wall so no sub was in the room. It was a really neat concept if your wife doesn't want big sub-woofer, boxes in the room. If you have unfinished space around your theater room anywhere, it might be an option worth investigating further.
7.4.4 Theater Room: JVC-RS46U, Silver Ticket AT 2.35:1 142”, Onkyo RZ830, Anthem PVA-7, Panasonic DBT-110, JBL Studio 270’s, 4 - 15" DIY Sealed Subs
3.1 Living Room: Samsung 64” F8500 Plasma, Anthem MRX 300, Dynaudio Audience 52’s, Dynaudio Audience 122C, NHT SubOne