The keep it simple answer is: Nobody is going to be able to tell you if it will be enough. You'll just have to listen and find out. Most competent car audio shops have a host of vehicle owned by the installers and salespeople that they will let you listen to. Find one with a similar setup to what you are looking at. For the type of music you listen to, (and this is a big generalization drawn from past experience) you will likely want a little more in a vehicle the size of an Explorer. I would recommend a single 12 (my favorite solution) or more likely for you as long as you don't mind giving up the space (although ported boxes tend to be larger, you would need the space for 2 subs instead of 1), 2 10's in a sealed enclosure with a little more power. This will yield a little more accuracy for techno-type music, than a ported box. Ported enclosures, while being louder, are more limited in their dynamic range, and generally not as "tight and punchy". What this means is they are louder at a specific frequency range depending on how the box is tuned, say from 40hz 75hz. Outside of this range they will be noticeably quieter and less accurate. They also do not have the air pressure of the enclosure to help act as a shock absorber to support the coil like a sealed enclosure does. As such, the sub cannot stop and start as quickly, which can translate into some of the notes bleeding together. Some people cannot hear the difference, others prefer one over the other. I, for one prefer sealed boxes, though they also have their minuses, such as generally needing more power for the amp, and generally being quieter than their ported counterparts. Again, you'll just have to listen to a few setups to decide what you like. Well designed ported enclosures can sound just as good as a sealed enclosure in the right application, and poorly designed sealed boxes can sound REALLY bad.
