any thoughts on this cabinet?

Hi everyone,
So I was hunting around and thinking about moving my 2420(in a 511b horn) and E145 (in a 4560 cabinet) into a more house-friendly cabinet and came across this:
http://www.hqspeaker.com/cabinets/a500i.html
It looks like a 511b mounted in the top, but I am not sure what that'd be for the bass...But I was thinking that perhaps I could just build a bass reflex for the bottom, following the JBL recommendation for the E145...
Anyway, I was just wondering if anyone had ideas about this or another integrated cabinet for the drivers I am using. I have also seen a large 'onken' enclosure that would be interesting...
Regards,
Byron