TH K2 II A Coro is designed to transfer the precious musical message of the Thesis electronics with absolute fidelity, with the ambition to be absolutely transparent, leaving room only to the emotion evoked by the music. The search for the best acoustic result was based upon overcoming the intrinsic limits of traditional loudspeakers. Through a finite element simulation software (FEM) conceived by the Audison R&D team, a mathematical model was developed, which they used to create, with an intense prototyping activity, the ideal transducer. The versatility of the TH 1.5 II and TH 6.5 II provides the ability for the user to set the crossover cut in a very wide range according to his preferences. This is possible thanks to the exceptional extension of the tweeter frequency response towards the medium frequencies (800 – 22 kHz) and to the very regular response of the woofer at medium-high frequencies (up to 4 kHz). Thanks to this versatility we have designed two cut-off options.