A speaker system typically doesn't reach its maximum operating temperature for at least 2 or more hours. Yet some manufacturers make power handling claims based on mere minutes of testing. At JBL, our power tests subject each speaker design to the kind of stress and strain it will get in years of actual use. JBL uses the IEC spectrum for testing speakers. IEC shaped noise places greater demands on a speaker than real music.
Transducers can fail due to excessive mechanical stress or excessive thermal stress.
One form of mechanical stress would be a mic stand through the speaker cone. JBL has overcome this failure mode by using heavy gauge steel grills on all live sound models. But there are more subtle ways in which a transducer can fail mechanically. The mechanical design of JBL Professional transducers has benefited from decades of experience and the best engineers in the industry. As a result, mechanical failure of a contemporary JBL speaker is a rare event.