Hello, I was thinking about getting a sealed cab for my Mesa 400+. The SWR Goliath III, which I use at the time seems not to be THE right cab for an all tube head. i saw that Ampeg 4x12's were produced for Geezer Butler and I love his tone, but I want to know if they are sealed or ported. On what other sealed cabs should I have a look at? BTW, I think a 8x10 would not be the right, because carrying it up and down the stairs of our rehearsal room is nearly impossible even with a 4x10. The cab don't need to be very clean and hifi, because I love overdrive and distortion on bass. thanks!!