I generally need one of these at a time. The pair is stupid loud. Much louder than I want to be near... the 15 and 5 driver combination (Faital Pro drivers) are strong and seem to be efficient. The box on the bottom is based on a design from TB'er
@5StringPocket. TB'er Singlemalt did the carpentry - he's good and it and I still have all 10 fingers ;-) I did the finishing pieces. I used the mid portion of a fEarful 12/6 to keep the lows out of the mid. The 15 runs full range. Simple and effective. 2 of these would be ridiculous ... IMO
I also do a lot of synth bass. Future Impact V4 driving either a Behringer Cat or a Moog Minitaur. Mostly the Minitaur because ...presets. I can get some scary stuff out of the Cat though ;-) So when I am running a rig, it needs to be fairly robust. This stuff is.
Power wise.... Quilter BB-803. I was an early adopter of the BB-800. I still ise it to ppwer a pair of passive subs. The Quilter stuff is strong... Tried and did not care for the 802. The 803 I like a lot.
For a 1 cab solution. Used fEarful 15/6. or one of it's variants from LDS,etc. Crazy loud. Reasonable neutral, the fearful design takes EQ really well. Big low end! I ran one of those one festival season. Large stages ... it was all the band needed. End of season though it was too large to be practical for me and I went to a 12/6 amd 12/sub. Then onto the Faital Pro based cabs. The top cab is from Mike Arnapol Soundworks.
For the record, my fave rig is ... a Shure IEM transmitter with 64 Audio cusrom molded IEM's...