I'm thinking of building my first DIY sub. I have been looking at the Stryke AV12 and AV15, along with the Adire subs. I would like to keep it under $500 (all materials included). The sub will be mostly used for music. I listen to bands like Dave Matthews, Metallica, Pearl Jam, Nirvana, The Beatles, Zeppelin, etc. I also listen to some Jazz and Classical. I want a sub that has nice tight "musical" bass (is that a low Q design?). it has to be pretty quick to keep up with my main speakers which are Dynaudio 1.3mkII's. I am going to use the sub from the 45hz region on down. The Dyn's have nice tight punchy bass down to around that region... I'm not really sure where to go from there. I've got 2 similar sized designs in WinISD right now. I have a 142 liter vented Stryke AV12, tuned to 17 or 18hz. Or I have a 150 liter closed AV15. The group delay of the vented box has me a little worried about its transient response, but I like it's extension... I like the group delay of the closed box... What would the differences in the designs be? What should I do? What would you do? Thoughts and help on my first project would be great! Thanks!