Hi guys, Im looking into adding a sub to my 2008 altima (with Bose) Im not looking for anything extreme in RMS liike when I had my RE HC a few years back in my older car. The sub I am looking at is either a 10 or 12' X. I have to admit im confused with the BP option. How much RMS does this add to the sub? The amp I was considering was a Diamond 300.2 that I can get at a very good price. Can someone also recommend a box for this sub? Preferably ported and if someone can let me know how this sub compares to something like a Diamond D3. I know its a lot of questions, but I do appreciate any help I can get. Thanks!