Thiel may or may not have 'left alone' the 3.6 for so long because they 'got it right' in the beginning. Personally, I suspect it is mostly because they were too busy addressing (successfully) the evolving demands of the HT segment and bringing out new flagship and entry-level products. Not that there's anything 'wrong' with the 3.6 that 'needed upgrading' either, but remember that Thiel, for all their influence and longevity, is still a pretty small company for the level of volume at which they operate and the number of products they offer. I just think there was a limit to how much they could do all at the same time. I also suspect that a potential engineering-vs.-marketing sticking point has more to do with the price range a new 3-series would have to occupy - as opposed to simply the challenge of achieving substantial enough improvement to justify a new model - and whether a new 3.7 would effectively kill the CS6.
Anyway, production of new 3.6's has for all practical purposes ground to a virtual halt nowadays. Thiel is no longer continuing to buy the Vifa drivers it uses due to very large price increases - presumably ones dictated by ever-smaller demand, and as models that once shared its tweeter were replaced in the lineup. Plus there are plenty of 3.6's available on the second-hand market. I think we can assume that the next 3-series will incorporate some kind of coincident driver array, since it is the only remaining Thiel not to do so (aside from the small 1.6, a near-full-range 2-way which does not as easily lend itself to such a design approach). Bringing this speaker out ASAP would seem like a no-brainer, since it likely stands to become their fastest seller ever. But I guess a lower-priced subwoofer and maybe a new 'statement'-level flagship model could still be competing for R&D time, though this is just speculation on my part, based mostly on reports of the options they were considering pursuing back before the latest round of new model introductions had taken place...
Anyway, production of new 3.6's has for all practical purposes ground to a virtual halt nowadays. Thiel is no longer continuing to buy the Vifa drivers it uses due to very large price increases - presumably ones dictated by ever-smaller demand, and as models that once shared its tweeter were replaced in the lineup. Plus there are plenty of 3.6's available on the second-hand market. I think we can assume that the next 3-series will incorporate some kind of coincident driver array, since it is the only remaining Thiel not to do so (aside from the small 1.6, a near-full-range 2-way which does not as easily lend itself to such a design approach). Bringing this speaker out ASAP would seem like a no-brainer, since it likely stands to become their fastest seller ever. But I guess a lower-priced subwoofer and maybe a new 'statement'-level flagship model could still be competing for R&D time, though this is just speculation on my part, based mostly on reports of the options they were considering pursuing back before the latest round of new model introductions had taken place...