I've got a pair of infinity speakers that each have (4) 6 1/2" bass drivers powered by a seperate 300 watt amp. I use my system mostly for watching concert DVD's. I feel I am missing the kick that is felt when being at an actual concert. Does a good sub, (Let's say and SVS pb-ultra), add the punch to all the drums? I'm not sure what frequency drum beats are at. I have no sub now, other then what is built in my speakers. I have the speaker settings set to large and the sub channel turned off on my reciever's settings. Can someone please put some light on this for me?