in fact.. if you look at the post 'bf titan 39' here on the board... we had to run a pair of very effecient subs in a live sound setting per side to get the effecientcy up. we found that running just a regular sub with the a-5's in an active thre way setup, that you couldnt tell the subs were running. this is with the 75 sq in vent opening on the a-5's. todays music in the clubs in very bass oriented..gets the girls dancing and the boys buying drinks. we also cross the subs out at just over the kick drum, which is brutal in a live setting