Sensitivity is only one of many factors. When talking about guitar sound sensitivity is a huge factor. With bass sound the quoted sensitivity is not as important. The bandwidth sensitivity is. Eminence makes it easy for you to compare drivers. Go to their website and under "resources" click on cabinet designs. Now compare different drivers. Pay special attention to excursion limited displacement, and maximum acoustical output. I think you will find that a kappalite 3012lf will put out more bass than an s2012, a deltalite 2512, or 2 of just about any other 12 that costs under $200.
If you don't think 2 12's will keep up, then get two kappalite 3015lf's and be done with it. I have direct experience with that speaker and i can tell you it is the best thing since sliced bread.