What are Ohms, and RMS?
Ohms is the measure of resistance in an electric circuit. Also referred to as impedance. In relation to speakers/subs it is the impedance of the speaker, and the load it would present to an amplifier when connected. The difference in ohms does not mean a speaker can handle more than on of a different value, but a lower ohm load on an amp would cause the amp to produce more power. RMS is Root Mean Square, or the average or nominal power, always go by RMS ratings and ignore peak values. More on RMS can be learned here, http://en.wikipedia.