sdecker - regarding the 2.4 vs 2.7, I can supply some contextualizaion and personal observations. I don't know either speaker well, but I heard both in September 2012 when the 2.7 was finalized, although our working comparisons were between the 2.7 and 3.7, which is a different story.
I think the 2.7 is an extraordinary speaker, but built and priced by a different standard than Jim's ethos. I also think that it veers away from the traditional role of the model 2, which was the svelte little sister to the model 3 big brother. The model two had always used a smaller diameter midrange than the three, along with the smaller woofer with higher crosspoint - resulting in less doppler distortion, lower inertia, and a more nimble, lithe personality for the model 2.
The 2.7 was developed under different circumstances and therefore different rules. Thiel needed a new product after Jim's death to demonstrate that they could produce a credible contender without him. I say it is a success, but not the same contender that Jim would have designed, because Thiel no longer had his considerable chops and long-range vision. Jim was working on a CS7.3 with a new, improved coincident, passively coupled high driver. (The CS7's high driver was developed in the CS2.3). That 7.3 high driver would then be tumbled down to the 2.5 - the way Jim Thiel did things. All those plans went on hold when Jim died and a successor engineer or company was not found to carry the torch.
A far simpler and executable fall-back plan was to take, as you mentioned, the extant 2.4 bass system including the woofer, passive and enclosure volume and mate it with the extant 3.7 wavy high driver, making XO changes to accommodate. One circumstance is that the higher woofer to mid crosspoint necessitates a very large capacitance coax feed. The 2.4 has 30uF feed capacitance and the 2.7 has 416uF, including a 400uF electrolytic. That's the only electrolytic feed cap since the 1976 model 02, as far as I know.
So, yes, the CS2.7 is a valid Jim Thiel tribute design with first order slopes, minimal diffraction and lots of learning rolled in. And it is good. Some forum members here and elsewhere choose it over the 3.7. But it is in some ways less elegant and demure than the next model 2 from Jim would have been.
Enjoy the ride, wherever you go.
I think the 2.7 is an extraordinary speaker, but built and priced by a different standard than Jim's ethos. I also think that it veers away from the traditional role of the model 2, which was the svelte little sister to the model 3 big brother. The model two had always used a smaller diameter midrange than the three, along with the smaller woofer with higher crosspoint - resulting in less doppler distortion, lower inertia, and a more nimble, lithe personality for the model 2.
The 2.7 was developed under different circumstances and therefore different rules. Thiel needed a new product after Jim's death to demonstrate that they could produce a credible contender without him. I say it is a success, but not the same contender that Jim would have designed, because Thiel no longer had his considerable chops and long-range vision. Jim was working on a CS7.3 with a new, improved coincident, passively coupled high driver. (The CS7's high driver was developed in the CS2.3). That 7.3 high driver would then be tumbled down to the 2.5 - the way Jim Thiel did things. All those plans went on hold when Jim died and a successor engineer or company was not found to carry the torch.
A far simpler and executable fall-back plan was to take, as you mentioned, the extant 2.4 bass system including the woofer, passive and enclosure volume and mate it with the extant 3.7 wavy high driver, making XO changes to accommodate. One circumstance is that the higher woofer to mid crosspoint necessitates a very large capacitance coax feed. The 2.4 has 30uF feed capacitance and the 2.7 has 416uF, including a 400uF electrolytic. That's the only electrolytic feed cap since the 1976 model 02, as far as I know.
So, yes, the CS2.7 is a valid Jim Thiel tribute design with first order slopes, minimal diffraction and lots of learning rolled in. And it is good. Some forum members here and elsewhere choose it over the 3.7. But it is in some ways less elegant and demure than the next model 2 from Jim would have been.
Enjoy the ride, wherever you go.
