I currently have a behringer 1x15 aluminum cone cab. I think the volume is 5.0 cubic feet. It's 25 4/5 x25 4/5 x 14 2/5. Per the web. Any way. I was thinking snout a peavy black widow 8 ohm. They tested it in a 3.5 cubic ft. Enclosure. What would using this sub in this big a box do to the sound. Any recommendations on a speaker for this enclosure. I want to add on a 2x10 and maybe go to a TC Elec 750 amp.