I have a 70's Bandmaster/Bassman tall cab with a pair of Swamp Thangs and a pair of 70's ceramics in it. The cab has a resonant hump around 100 Hz. I was thinking about a brighter speaker to mix with the ST's. There's not much info about the Black Powder. There's a bit more info about the Screamin Eagle. I'm mostly doing punk, rock, stoner/doom, and 80's metal. Mesa DC-5, Laney AOR 50, Carvin VT-50, homebrew 2204-ish heads. Any experiences with either speaker mixed with the ST? Either speaker in a big 412?