The majority of Speaker specs I understand completely, there is just two that have me a little stumped. They are Sensitivity, and nominal impedance. we'll start with sensitivity, when they refer say 91db, or 88db (for example) what does it mean and how does it affect performance, and sound quality. As for nominal impedance, what is it refering to and how would an impedance of 8ohms perform compared to 4ohms?

if anyone could answer this, you would just make my day haha