Tweeter midrange concentric vs. separate drivers

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Thiel also has different concentric tweeter midrange driver such as the one found in the CS2.7. I believe it's a more conventional driver since it requires an electronic xover.

Their flat concentric is likely awful, based on the fatiguing sound of the CS3.7. I suspect there's just a lot of diffraction from the midrange, exacerbated by Thiel's quirky crossover proclivities. Also the ring midrange does not load the tweeter well.

The pity with Thiel is, they made a few nice speakers for a little while, after a PSB guy took over design. However, they were priced high for speakers using ScanSpeak Discovery drivers (for the most part) and the old Thiel fans weren't ready for designs based on modern best practices rather than 1st order fundamentalism.

But regardless, I wish there are more quality concentric drivers offered commercially off the shelf.

Buy a pair of KEF Q100s for $250 as long as they last, toss the cabinet and crossover, and you have a high-value pair of excellent concentric drivers. Frankly much better than any wideband or concentric driver Thiel ever used.
 
I think every configuration has its strength and weakness. Full range driver does not produce treble frequencies very well. Maybe it can be augmented with a super tweeter but then we are back at the midrange tweeter integration.

I don't really thinkthe Thiel will do much better than these? It is not a real tweeter. Look at the off-axis response of some of the Markaudio drivers, they are quite good. I think the dustcap of those has a bit of a similar function as the Thiel driver. Sure, the response is not as smooth as real tweeter, but it's quite good. Even something as SB65WBAC25-4 would probably be pretty good.

BTW, I've not headed any of them yet, so cannot comment on the audible qualities
 
Pallas, looks like to have a bone to pick with Thiel. I personally admire what they've done.

My "bone to pick" is with crappy drivers and bad-sounding speakers. I'm not familiar with many Thiels, but here are the ones I've heard.

The CS2.4 sounds kinda ok at low volumes. A little low in resolution, but acceptable enough I guess. At higher volumes it just falls apart because of its glaringly boom-sizzle voicing.

The CS3.7 is a train wreck. Fatiguing after a short listen at any volume. Could be the 1st order crossover fundamentalism, but I suspect the wavy ring radiator diffraction generator midrange is irredeemable.

The last tower - don't remember the name, maybe just Thiel Tower or something like that: it had a waveguide-loaded tweeter and what looked like Scan Disco midrange/woofer - was really good. Unfortunately for Thiel, the modern design alienated their old customers. Also, Revel's Performa towers were just as good or better sounding, had similar fit/finish, and were and a good bit cheaper both in MSRP and street prices.
 
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The SB Acoustics SB65 works very similar to the "tweeter" in the Thiel CS2.4. There's a dome on the cone that's decoupled via a damping layer. Basically the idea is that only the dome will move at high frequency.

The SB65 is really nice.
 
There's something about smaller coaxials and fullrange drivers being used as the mid/high section and leaving the lows to a dedicated woofer. In my experience (in general) it sounds more coherent then a regular three-way system. There's this Oberton PA 8" coaxial that I have used with excellent results, very accurate and dynamic.
Right now I'm building this home-studio setup with the Mark Audio CHR-70 as small monitors and an active 12" sub. I really like these alu cone drivers, you can't go wrong with them in this price range and with a few "tricks" they sound damn good. The "dome" of the CHR-70 is not decoupled but it still works pretty good, you do not see the messyness in the upper midrange that most of the whizzer equipped fullrange drivers have. Pictures below show the on-axis measurements of the CHR-70 in a small round enclosure. I did compensate the baffle-step and the 13khz cone break-up with two LCR networks.
 

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I think every configuration has its strength and weakness. Full range driver does not produce treble frequencies very well. Maybe it can be augmented with a super tweeter but then we are back at the midrange tweeter integration.

One of my favorite concepts is a three-way system with a fullrange driver doing the mids/highs and using an ambient tweeter to compensate for the lacking off-axis dispersion above 10khz. It's a compromise, but IMHO a good one. Below one of my designs based on that concept.
 

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I listened to the Thiel 3.7 and 2.4SE in their Lexington showroom back in 2007. I really liked the presentation of the 2.4SE more than the 3.7. The 3.7 seemed to unload the PR very easily, and yet didn't dig all that deep. I also felt the ring-coax was not really all that well done and I liked the 2.4SE midrange more. That sympathetic dustcap via mechanical xover really was something special. Airy, sweet, and well resolving, IMO. The aluminum bass driver was tonally accurate, and did not really boom in my opinion. They played deeper than the 3.7 did.

I'll be working with the B&C 5FCX44 as soon as I get the cabinets assembled. I hope them to be something as special. The review in Voice Coil showed a very linear and well aligned suspension, as well as having more Bl for a longer Xmax than specified. Some of that is moot as I'll be using it as a mid and high as opposed to for bass duties.

Later,
Wolf
 
The voice coil is the same diameter as the central dome so works like a dome tweeter with a cone midrange attached so very similar to the Thiel.

I wouldn't go so far as to say that. The dome and cone on the Thiel are not directly connected. There is an elastic bond between them via a piece of spider material from what I'm told, so they are mechanically separated.

Later,
Wolf
 
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