ok this sounds all kinds of dumb to me... it says 2200w max so you want to run 2000w+. max on these brands usually means thats how much they can take until they fail. some people can run a lot more power than rms to a sub but these people KNOW what they are doing and how to build a box to make the sub handle it. you said you have a dual box, prefab? not going to take 2k.
how did you test you boss amp? you hooked up another amp and it sounded the same so it must do X power? no TL so see if it was any louder? no clamp meter? not even a dmm? doesnt sound like you tested shit.
you can "hear" the amp not giving as much power... maybe what you are hearing is voltage drop? ever test that? maybe your already dropping to 10v, "so lets throw a bigger amp in!" to get 2000+ watts you NEED electrical upgrades, what have you done?