With all this talk about the best 12-inch subwoofer, you're probably wondering why we're fixating on the size so much. When it comes to hitting those low notes, the more surface area, the better. If you play guitar, think about how an open note is the deepest note on a string. That's because the section of the string actually reverberating is the longest this way, and a longer string means more surface area, which means a deeper note. See how subwoofers work The same mechanism is at work with our subwoofers. (Or at least, I assume so. Some physicists can probably explain that that's completely inaccurate, but the analogy works.) The bigger the subwoofer, the deeper the note. There are reasons why you'd want two smaller subwoofers instead of one big one, but if you want to hit those low notes, then you'll want the biggest subwoofer possible.