Sunn Concert Bass -> QSC rmx 1450 power amp -> Kustom 2x15???

[doopskunk]

I'm not very tech savvy and I am trying a new setup with my bass equipment, so I want to make sure I'm not doing anything that could damage any of the components. I recently came into a QSC rmx 1450 power amp which I believe is two channels, each 450 watts, into 4 ohms. I heard that it can be really loud for bass when matched with a good pre-amp. I had previously been using my Sunn Concert Bass (the silver plated one with the distortion knob), which I believe is a 200 watts into 4 ohms, and a 4 ohm Kustom 2x15 cab. Since I'm in a punk/powerviolence band, I need to be LOUD and I wasn't nearly there with that setup. So I had a thought that I would use my Sunn Concert as the "pre-amp" for the QSC. I tried it the other day while practicing with my band and I definitely got a very noticeable volume boost. The guitarist in my band (who is much more tech savvy) said I should research to make sure this is a setup that won't be detrimental to any of the equipment involved, but I have yet to find anything helpful in my research. Anyone have any advice/knowledge they could pass on?