That is indeed ferrofluid. It doesn’t leak out because the magnetic field keeps it in place. Tweeter manufacturers have been using it for decades, and the tweeters live for decades.
Woofer mic probably does (real time) analog feedback to perform correction of nonlinear distortion. Not necessarily with DSP. AFAIK the first company to mass produce a product (subwoofer) with this feature was Velodyne in the 90s.
Could you tell us the value of the big main black colored capacitor above?
@jstew that glue doesn’t hold anything down. It damps vibrations to prevent failure of the legs/solder joints.
Could you tell us the DC resistance of the voice coil?
Quando isso acontecer, você poderá ver um gráfico da reputação que ele adquiriu ao longo do tempo.
Aqui está uma prévia de como será o gráfico:
Nenhuma reputação adquirida ainda.