Serious question: are you burping a 55 at 60Hz or doing a 55 playing music in the 30-50Hz range?I'm running $60/pair RF Punch Coax 6.5s on 75w each. I had to back the stupid things down because they were hurting. They keep up w/ a 155 sub stage just fine.
My S-10 build is going to be T3 Components on 220w each. Should have no problems getting loud.
I really don't see a cheapo set of coax's keeping up with 55's on music when doing demos, but if you're happy with how it sounds that's all that matters....