lf rcf n 451 21 Hours of Operation for qualitée price / realization and use in sub box in pass band sound on plane 18, hp rcf having the same parameters as +/- hp planned for the subwoofer frequency of use +/- (30hz / 90Hz) for the amplified moment with behringer ep 4000 in Bridger (cheap) and filtered with dcx behringer also ebenisterie birch finland 18 minutes (1 3mx1,50m plate for cash (+/- 180 euro plate), glued screwed , well ... really good, I have planned to redo 3 others