This is my first post after lurking around for quite a while. I've been into home theater for a long time but this diy is completed new to me. I plan on building a sub based on a tempest but I'm not sure whether to continue looking for a sonotube supplier in Maryland or build an enclosure. The problem is I have limited woodworking tools and even less experience. Long story short: I am now planning on building an smaller sub based on an 8" or 10" Dayton Quatro since I can purchase 12" sonotubes at my local HD. At least I can get my feet wet, so to speak, and see how much work is really envolved. The problem: I can not figure out how to model drivers using lspcad! Question 1: Does the version of lspcad from adire only work for their products? If not, how do I enter vas, qts, etc. The fields are greyed-out and do not accept input. Question 2: Is there another free version of lspcad that allows me to model any speaker? Question 3: Should I forget lspcad for now and just use the specs on Parts Express's website for the drivers? I realize these drivers (8"&10") will not give me what I am after (hence the tempest) but I still want the best possible performance I can get. Maybe that is too much for my first post but I'm getting really anxious about building a sub after reading this forum for so long! TIA for any help.