ferrofluide (FFL)

In dynamic tweeters, the mechanical oscillating system of voice coil, diaphragm and surround is damped with ferrofluid, a magnetic fluid. The ferrofluid is placed in the air gap where the voice coil is located and dampens the movement of the oscillating system. This increases the Qms value, which stands for mechanical Q, and which is caused by the friction of the surround and the centering diaphragm. As a result, the impedance rise at resonant frequency is not as pronounced. The tweeter can withstand higher loads and dissipates the resulting heat losses better via the ferrofluid.