C6 MKII In-Wall Speaker The C6 MKII is a newly released in-ceiling speaker from UK based speaker company Compact Audio. Designed to offer the highest quality sound at a competitive price the speaker is built around a lightweight high performance woven glass fiber cone. This material coupled with a powerful magnet assembly and quality crossover results in a defined bass and smooth Hi/Mid frequency response. The design also features a quick fit mounting system eliminating the need to tighten the four long screws found on the vast majority of ceiling speaker designs.