My rents have a pair of the old Series II Advents. the cabs are in amazing condition, not a major scratch anywhere. The only thing is the tweets are blown and the surrounds are toast. I know theres a big following for old advents but I think its time to upgrade the components. So I have been thinking of what i could do with them, i was initailly thinking of going with cheap dayton parts but i want something a bit more high end. I am esitmating the cab right arind 1.6 cuft, or 47 liters, so I have the internal space for the HE10 as they only require 29 liters. I could prob tune them a bit lower. My only concern would be how would the cross over deal with the recessed baffle of the advent, or if it will even factor into it. I am not sure what the dimensions are of the advent driver, but if need be i am sure that i could redo the entire baffle with proper placement of the HE10, I would bring it up so that it would be more at ear level, and move the port down below. So what do you guys think about this type of project, I bet it would only take me a weekend and my dad would have some kicking speakers again. below is a pic of the same models that my rents have to give you some ideas.