This is the British English definition of SOLE. View American English definition of SOLE. Change your default dictionary to American English. View the pronunciation for SOLE.
Deadband is also known as hysteresis and is the amount of a measured variable (pressure, temperature, etc.) between the point where a switch closes and then re-opens. It can be implemented is software if you have an analog input (i.e., open at 1.02 PSI, close at 0.98 PSI) or designed into a switching mechanism. Often the deadband of a switch is fixed and cannot be adjusted. A typical example is in a wall thermostat in your house.
Now if your speaker is a perfectly resistive load, your 10 ufd series capacitor will be a perfect passive 6 db per octave High Pass (HP) filter. Don't worry, life is not that simple. The other important element used in a crossover network is the Inductor; sometimes called a choke, and sometimes called a coil. They are all refer to the same thing. The Inductor is in many ways the inverse of the capacitor.