dillinja's system has got loads of 18" scoop bins. they have extreme out put and nice low response. they are quite fun to build i have got a few 12" scoop bins.
as for what cone he loaded them with. i would place a guess that its an RCF driver. or Precision devices diver
Precision devices are by far the best cones you can get in the uk but cost a small fortune.
scoops a nice but they cant do transients that well. (techno kick drums)
am yet to hear he system first hand. but i am told the top end was totally bollocks untill he decided to bin it and go for funktion 1 resolution 5 cabinets. which i have heard many times. very nice sound.