Unsound: Thiels, at least as I have gotten the impression, have long been thought to have excellent bass no matter any other perceived shortcomings, and I concur with this view. I don't personally believe that the line's bass response is at all connected with the charge of 'brightness' that has been leveled at them over the years, and don't think generally that a speaker's true low-end performance has much bearing on the perception of mid- and upper-range listenability.
As far as driver spacing goes, it seems to me that Thiel speakers' time-aligned construction dictates the driver spacing based on the angle of the baffle slope-back. If the baffles were angled back more steeply, the drivers could be more closely grouped, but would also aim upward more severely, requiring even lower placement overall with respect to the listener's seated ear height (Thiels already feature slightly lower-placed upper-frequency drivers than many other brands, presumably due to this angled-baffle factor). A more steeply-raked baffle would also require a deeper-dimensioned cabinet to enclose the same volume, though Thiels as designed are not especially deep-cabineted speakers by today's standards.
Regarding in-room placement, great soundstaging and imaging are always harmed by close wall proximity, including the front wall. I have found my Thiels to be balanced, bass-wise, for optimal placement of at least a couple of feet out into the room - much closer and they're too bassy, which is as it should be. For really big rooms, you'd have to go with one of the bigger models. I don't think any speaker can sound its best in a really small room, and don't think a near-full-range floorstander ought to be designed to try.
I'm not as down as you about the bass-reflex vs. sealed-box evolution of the line, considering the trade-offs of greater driver mass (less speed and controlability), and of system cost, complexity, and possibly lowered ultimate transparency involved in employing the latter in combination with outboard active EQ. But you would get no argument from me if JT started turning out designs that didn't fall below 4 ohms at any frequency - or even if he introduced an 8 ohm design, heaven forfend.
To me, the next step in the advancement of the line should logically come in the cabinet arena: away from single-baffle, square-backed, parallel-sided, MDF-built cabinets, and toward something more radical and high-tech (and unfortunately more expensive, along with less furniture-looking) in the way of materials and shapes. (However, their spotty history of flirtations with exotic molded-baffle variants, and their clear orientation as a wooden-cabinet manufacturer offering a moderately-priced product for the quality, both argue against any sudden leaps foward on this front.) Thiel's drivers, crossovers, and basic design concept are all near as good as they could be while eschewing large multiple-driver arrays; it's only their cabinets that hold them back a bit in the no-holds barred sweepstakes, even for all their strengths (such as the rounded baffle edges, acoustically-designed grilles, and relative ease of room integration) at the present price points. This is the area in which I would like to see what JT can do taking a page from the Wilsons, B&Ws, and Kharmas of this world as his inspiration, but of course those companies are either much larger or much costlier than Thiel.
As far as driver spacing goes, it seems to me that Thiel speakers' time-aligned construction dictates the driver spacing based on the angle of the baffle slope-back. If the baffles were angled back more steeply, the drivers could be more closely grouped, but would also aim upward more severely, requiring even lower placement overall with respect to the listener's seated ear height (Thiels already feature slightly lower-placed upper-frequency drivers than many other brands, presumably due to this angled-baffle factor). A more steeply-raked baffle would also require a deeper-dimensioned cabinet to enclose the same volume, though Thiels as designed are not especially deep-cabineted speakers by today's standards.
Regarding in-room placement, great soundstaging and imaging are always harmed by close wall proximity, including the front wall. I have found my Thiels to be balanced, bass-wise, for optimal placement of at least a couple of feet out into the room - much closer and they're too bassy, which is as it should be. For really big rooms, you'd have to go with one of the bigger models. I don't think any speaker can sound its best in a really small room, and don't think a near-full-range floorstander ought to be designed to try.
I'm not as down as you about the bass-reflex vs. sealed-box evolution of the line, considering the trade-offs of greater driver mass (less speed and controlability), and of system cost, complexity, and possibly lowered ultimate transparency involved in employing the latter in combination with outboard active EQ. But you would get no argument from me if JT started turning out designs that didn't fall below 4 ohms at any frequency - or even if he introduced an 8 ohm design, heaven forfend.
To me, the next step in the advancement of the line should logically come in the cabinet arena: away from single-baffle, square-backed, parallel-sided, MDF-built cabinets, and toward something more radical and high-tech (and unfortunately more expensive, along with less furniture-looking) in the way of materials and shapes. (However, their spotty history of flirtations with exotic molded-baffle variants, and their clear orientation as a wooden-cabinet manufacturer offering a moderately-priced product for the quality, both argue against any sudden leaps foward on this front.) Thiel's drivers, crossovers, and basic design concept are all near as good as they could be while eschewing large multiple-driver arrays; it's only their cabinets that hold them back a bit in the no-holds barred sweepstakes, even for all their strengths (such as the rounded baffle edges, acoustically-designed grilles, and relative ease of room integration) at the present price points. This is the area in which I would like to see what JT can do taking a page from the Wilsons, B&Ws, and Kharmas of this world as his inspiration, but of course those companies are either much larger or much costlier than Thiel.