The 8MB500 mid-bass transducer has been developed in response to a specific market requirement for a 200 mm (8 in) midbass driver which combines excellent linearity with good efficiency and power handling capabilities. It is primarily intended for use as a midbass driver in compact 2-way reflex enclosures with a 1 inch compression driver or tweeter but as a result of its versatile characteristics, it can also be used in multiway systems. The curvilinear, treated paper cone is formed using a unique wood pulp composition designed to achieve the best possible rigidity and stiffness. This is carried by a polycotton multiroll surround to provide increased excursion whilst controlling break up modes. The 50 mm (2 inch) aluminum wire voice coil employs same Interleaved Sandwich Voice coil (ISV) technology. It is composed of a high strength fiberglas former carrying windings on both the outer and inner surfaces to achieve a mass balanced coil. This results in an extremely linear motor assembly which, in conjunction with the highly advanced design of the magnetic structure, provides a high force factor or BL. The voice coil is cooled by incorporating airways between the chassis back plate and the magnetic top plate to channel heated air away from the voice coil and gap and dissipate it. In-house FEA CAD facilities have been used to optimise flux density and BL factor within the air gap. Due to the increasing use of sound systems at outdoor events, the 8MB500 ability to perform in humid environments is a key feature. This has been achieved using an exclusive cone treatment which renders the cone resistant to humidity.