Yes, I know the "stacking cabinets with different speaker size" question will forever be debated, but... I am currently running an Ampeg PF-500 with a GK 410 SBX, which is more than enough for small rooms, and for larger I can just use the XLR out on the back of the head for extra headroom if needed. I play in 2 blues bands, one 4-man with guitar & harp and one 5-man with guitar, sax, and female lead. I have played through both the Ampeg PF-115LF and PF-410HLF (separately), and I love each cab. I am thinking of trading in the GK and buying both Ampeg cabs because I do not like going DI unless I really have to, and I would appreciate the option for headroom from the stack, or just to have the option of each individually. Any thoughts/suggestions from the TB community on how the stack would sound? Also, does anyone have a quick link that explains the physics behind the pros/cons of stacking speakers of different size? Thanks!