Hi I have a homebuilt sub woofer hanging off my AV amp. The sub has an FC of 30Hz and seems to perform well. The amp sends everything below 90Hz to it. My friend has a large speaker being driven also from his LF AV amp output. His sub does not go as low as mine but performs very well at that bass frequency's which gives you lots of punch (like in music). This is very noticeable in something like the first disco scene of blade. In this scene his has an abundance of hard tight bass punch (from his sub) which seems to hit u right in the chest, just like if you were at a disco. My sub does not have this punch but more of a lower sub bass. My questions :- What frequency is this type of bass at. I would of imagined about 150Hz but his speaker is connected to his LF output on his Sherwood AV amp so it must be below 100hz. I would like to either adjust my sub to a same sort of frequency (at the cost of low end perhaps). I assume i would do this by making the enclosure smaller and changing the tuning. However I have played around with the tuning and internal volume but doesnt make a lot of difference. Would a better driver (ie shiva long Xmax) give me low and powerful sub bass ? If I decided to keep my existing sub in tact (10" in 80L box) and build another. To allow higher frequencies to it can i connect it to one of my main speakers and then filter the, lets say 150Hz and below to it ? What u all think?