Hertz ST44
The ST 44 car audio compression driver, like the ST 25 and the ST 35, employs a CCAR (Copper Clad Aluminum Ribbon) voice coil featuring an extra-light aluminum membrane with high thermal dissipation as well as an anodized aluminum body, for maximum damping and vibration rejection. It additionally features a 44 mm (1.7 in.) voice coil and a powerful ferrite magnet, creating maximum SPL in extreme installations.