In the WinISD program how do I go about choosing the right alignment?
Usually higher priced subs have more Xmax so they will produce more output. The 15" Reference HF has a Fs of 18 hz which is good for producing the low frequencies required by a sub, compared to a sub with a Fs of 28 hz. Most subs are crossed oner at 80 hz so the 800 hz upper limit of the 15" Reference HF doesn't really matter for sub duty, unless you have other plans for it.What makes one driver better than another.
Using the same driver, porting will give you more low end output then a sealed cabinetIf I choose a 15" driver and I want to shake in my seat, but not necessarily tear my house apart would I want to port, and if so how many?
How linear (accurate) the sub is and more Xmax (cone excursion) are the two biggest reasons.What makes one driver better than another, If freq range and power handling are the same?
That depends on the size of the room and how big a box you are willing to accept. "Earth shaking lows" for $600 usually means a large ported enclosure. How big is the room and is the room open to other areas?I am mainly concerned about getting the really earth shaking lows. Could this be accomplished with $600?