Hi, I live in the UK and am just about to embark on building my first sub. I plan to do it in stages, keeping it simple initially and then adding stuff as I go along. My initial thoughts are: Possibly an Audax 10 or 12" Driver (PR240Z0 or HT300DM)as we're a bit limited for decent drivers under £100 over here and anything coming from the US costs a fortune in postage! A sealed enclosure of 60L made of 30mm MDF with 4mm Aluminium backplate. Initially using it for HT from the Subwoofer output of a Marantz SR4200 Receiver so just gonna start with a Linkwitz-Riley Transform circuit tuned to 20HZ into a salvaged 100W BK Electronics Amp, will then add crossover later. Couple of questions: 1. If I'm downward firing it will I need totally adjustable phase control or will the 0 or 180 switch on the transform circuit suffice? 2. If not, any suggestions of how to incorporate one? 3. Best software tool to use? Last but not least, if I then want to use it for Music what things should I be thinking about and what would be the best way to connect it up? Thanks in advance. Paul Total Newbie.