Thiel Owners

I think different frequency range presents its own difficulty.  The upper mid/treble region does have its own issues.  On the opposite pole, the lower bass has its own unique issues as well.  I've designed speakers with both ported and seal designs, and the ported has more "bass", although the seal bass theoretically can extend lower freq., it has a less perceived bass vs. the ported design.  On the flip side, the ported has a higher order high pass slope, so it has more group delay vs. the more shallow slop of the seal bass design.  For monitor design with smaller woofer, a ported design makes more sense since it has "more bass", at the same time, it is small enough that does not load up the room and may cause room issues.  I've used seal bass design for monitor and they just do not have enough bass to justify the more "bass quality".

For three way design, with a larger 8in woofer for example, you could afford to use seal design, but given the same 8in woofer, I could clearly hear the less bass output from the seal design.  I think if you have a good cabinet design, a ported 8in woofer will sound just as good and a 8in. woofer is still small enough that will not load up the room and cause issues and that is if the cabinet is well designed.

Most Thiel designs use Passive Radiator.  In theory, it has a higher cut-off vs ported, but lower cut-off vs the seal design, so it is somewhat in between, with respect to efficiency and transient response.  The ported design has the most bass efficiency but poor transient response, the seal design on the other hands has the least efficiency but the best transient response, and of course the Passive Radiator is somewhat in between.

Mr Bill - the CS1.7 is a real pot of soup. It represents the final battle in Thiel's hope for survival. I have patched together the story from reliable insider sources and first-hand evidence, and here's the thumb-nail. The 1.7 was codeveloped along with the 2.7 by Kathy's home team and the Canadian consultants previously outlined in this forum. The 2.7 was introduced in the fall of 2012 as a re-statement of Jim's design goals by his surviving company. The 1.7 was being readied for introduction at January 2013 CES, after the purchase by New Thiel. They pulled it for Mark Mason to "design a better speaker" on the 1.x platform. The resulting 1.7 had a more robust tweeter and 4th order crossovers. An argument ensued as to whether they could-should call it a "coherent source", since they owned the trademark; but the loyalists insisted it wasn't a coherent source, and I concur. Heads rolled the Dawn and Gary and Steve DeFuria and Bob Brown (the leading loyalists) got fired. Lana and Rob kept their heads low and stayed on. And the circus commenced which led to the liquidation bankruptcy which is still incomplete.
Stereophile stayed out of it and didn't review the 1.7. I have seen no other reviews. I know the cabinet was beefed up. I know the tweeter was improved - quite good I understand. The slotted port is the same as the 1.6 and the woofer had been developed by old Thiel. The 1.7 as introduced has a smoother frequency response and it handles more power due to the 4th order slopes. Its anechoic tonal balance peaks at 100Hz and falls about 6dB to treble, so it's balanced like a B&W rather than flat like a Thiel.

In the world of magic and speculation, interested loyalists might acquire the few extant pairs of 1.7s for later conversion to the 2013 first order crossovers and have a final tribute to Jim Thiel's design legacy. If I live long enough or am able to create a successor organization, I would relish that possibility. In the mean time, the current CS1.7 is a bit of a hybrid, mostly Thiel with a core dose of PSB/Mark Mason/New Thiel crossover slopes, which by world standards is what is expected in a modern speaker.

Happy New Year and New Decade, all

mr_bill
Welcome! Good to see you here.  The CS 1.7 is an interesting loudpeaker.I am not certain if one Panel member owns this mode?  Stay tuned for an answer to your query.
Happy Listening!

tomthiel
Thank You for addressing the query regarding 1.7 model. Very interesting history around this particular loudspeaker.  I, for one, am looking forward to more Thiel Audio history lessons in 2020.
Happy Listening!

The story of the CS1.7 from Tom is very interesting since it told a story of what is superior - the fourth order xover that allows for better power handling and "smoother" treble response, but of course it is not time-phase coherent which some view as having technical superiority.  I was wondering whether the reason it was not well-received by the Thiel loyalists because it was not a time-coherent design or of some other reason?  Is it possible that even if the CS1.7 is "better", it would not have been embraced by Thiel loyalists no matter what because it was not time-phase coherent?  

I guess it could be viewed under the lens of a philosophical debate between first order vs higher order, and not based on the technical merits?  I am just asking since I don't know the details, but it seems like a perfect example of what has been arguing within the audiophile communities: first order vs. higher order.