The MAXX’s low frequency enclosure is constructed from a high-density, phenolic resin based composite. This composite meets and exceeds the highest of ANSI test standards for its use, while offering very tight tolerances, high hardness, uniform density, and dimensional stability. In the construction of the MAXX, Wilson Audio uses two types of composites dubbed “X”material and “M” material.These strategic combinations of X and M materials are used in the two midrange modules,resulting in the most inert enclosures yet produced. X material is used exclusively in the woofer and tweeter modules.