Andy - I haven't seen the CS6 XO, but can comment generally. Jim employed all pass filters - Zobels and custom - to counter rising impedance with rising frequency as well as shaping networks to trim each driver toward its theoretical optimum response. Over the years, including the first-tier New Thiel period, reviewers, dealers and other knowledgeable folks would counsel Jim to scrap all that stuff. He was steadfast in his desire to create an ideal resistive load. The "amp problem" would be far worse if Thiel's low impedance x first order were to introduce the additional burdens of reactivity.
Our present 'R' approach (Beetle's 2.4s and my PP & 1.6 experiments) is to upgrade all those components. The degree of audibility of parallel / shunt / non-series feed components is far greater than generally believed. Improvement can be heard via a higher voltage cap of the same construction - even in circuits that "don't matter much".
I would appreciate seeing the XO picture and especially comments from you and our other DIYs. 'The veil' is quite delicate and expensive to address.
Our present 'R' approach (Beetle's 2.4s and my PP & 1.6 experiments) is to upgrade all those components. The degree of audibility of parallel / shunt / non-series feed components is far greater than generally believed. Improvement can be heard via a higher voltage cap of the same construction - even in circuits that "don't matter much".
I would appreciate seeing the XO picture and especially comments from you and our other DIYs. 'The veil' is quite delicate and expensive to address.