Thiel Owners

Prof,

I didn't get to listen to the CS2.7, but from what I've read, the CS2.4 concentric driver uses mechanical cross over where as the CS2.7 uses electrical xover.  It means that the CS2.4 driver probably uses a high pass capacitor in the signal pass and since the midrange need a lower xover frequency, the capacitor probably has a large value which usually is not optimal for high frequency.  The signal has to pass through this capacitor even for high frequency.

I don't have the information but if I was correct about the CS2.7 concentric driver being electronically xover, the tweeter can have its own xover which means it can be optimized using a more appropriate capacitor therefore it may explain what you heard in term of the treble glow.

The CS2.4SE has upgraded capacitors and although I don't know the specific detail, but my guess it's the series capacitor of the concentric midrange is most likely.  These high end capacitors do cost a lot of money.  For example, a typical for a tweeter capacitor is around 5.6uf which could cost somewhere from $50 - $200 depends on how much you want to spend.  For the CS2.4, since the midrange part has to play much lower frequency, the capacitor could be as high as 10uf or more which will cost even more.  A quick look up, a 10uf Mundorf Supreme is $55.0.  I've read somewhere that the capacitor used in the CS2.4 is Clarity SA which although a good cap but probably not the best.  When I used Clarity SA cap in my own speaker tweeter xover, for example Cowboy Junkies Trinity Session track Mining for Gold, the background noise of the recording is not that apparent.  But when I switch to Mundorf Supreme cap, the background noise was a lot more apparent and more 3 dimensional.  When I listen to the CS2.4, I always told myself that the treble could use better capacitors.

As for comparing plasma vs. LCD or LED, I have always prefer plasma over LCD or LED not only for having wider viewing angle, but plasma was always more natural to me.  A lot of people may not realize it but picture processing also use filters not that unlike xover in speaker.  They also high order or low filter.  High order filter in picture processing allows for sharper and clearer image, but at the same time less natural - sort of like music as well.  Each TV manufacturer has its own picture characteristic.  Sony tends to have a more vibrant and sharper image.  Where as Panasonic tends to have a softer picture and I suspect it has to do with the filter design.

In the few minutes I have . . . Andy, good observations - the 2.4 upper coax is crossed over as a single driver - the electrical signal drives the tweeter only, and the midrange piggy-backs through a mechanical elastic surround. Indeed the CC-SAs in the 2.4SE are less than state of the art, but at the time were CC's best offering. Regarding the "glow", Thiel always avoided artifacts even if they sound beautiful. In my present upgrade work with beetlemania, we have chosen ClarityCap CSA's which are 2 generations beyond the SA and are extremely good as being extremely neutral, without artifacts. We're testing efficacy of various bypasses in parallel to the CSAs.

You are correct about the 2.7 XO midrange feed cap. It is a 400uF electrolytic, which is audio grade, but nonetheless degrades the mid signal a little, even though it is bypassed by a 15uF polypropylene and a 1uF styrene & tin foil. My upgrade strategy is to eliminate all electrolytics (somehow!) to make the speakers virtually perpetual (electrolytics drift and fail over time). As you say, great caps are very expensive. I am assembling cap bundles based on a custom Japanese best in world film, bypassed by CC CSAs, rebypassed by the custom Thiel Styrene/tin and possibly a CC-CMR - all depending on which circuits. Much comparative evaluation will continue toward finding the best performance/ cost plateaus. It is easy to spend $thousands on caps. We are likely to have at least 2 upgrade levels for each of the products we address. The 2.4 is on the list and progress is being made slowly but slowly. 

Excellent discussion Andy, Tom, Prof
I know that Beetlemania and Tom, specifically, are working diligently on this XO project that will benefit us very soon. I am looking forward to the final products for upgrade and excited by ClarityCap CSA best offerings.
To address Andy's initial query, yes, the CS 2.4SE is an extra dose of sweetness to an already sweet CS 2.4 loudspeaker in stock form.

Happy Listening!

I'm still a Thiel owner (my entire HT is Thiel and my subwoofer is a Thiel SS2/Integrator), but my main speakers are as of last night Audio Physic Avanti 3. On a whim (well not so much as my buddy has a pair of AP Virgo 2's), I listened to them and was completely blown away. They do everything that I love about the Thiel's equally well, but added a smoothness and that famous AP ability to "disappear".

The only thing I really had to give was the Cherry color of the AP vs. the maple that makes my 2.4's look so stunning. Guess you can't have it all!

It's a shame to keep the 2.4's in storage (well, in a finished attic, so not much of a storage per se), so I will put them up for sale. If I had a second system, I would keep them, but I simply don't have the space for that (I've already claimed a room for my stereo and the basement for the HT, so I can't ask the wife for yet another space...)

After spending a few weeks with the CS2.4, I start to
notice a possible sound signature or if I am a bit
overly critical, a possible weakness given the design.
As with most Thiel speakers, the mid range driver is
smaller than the average mid of other manufacturers.
I was not part of the design process but I think the
main reason for using small mid driver has to do with
time-phase coherent.
We Americans have a say "There is no substitute for
cubic in." In speaker design, I guess the equivalent
would be "There is no substitute for membrane area."

When a small mid driver is used, one has to cross
over to the bass at a rather high frequency so the
bass driver can help out the mid when playing loud.
In the case of the CS2.4, I believe I've read that
the cross over freq. to the bass is around 1KHz.
But still ultimately the laws of physics come into
play and being a small mid the advantage is faster
transient speed and better clarity which is the
hall mark of the CS2.4. On the down side though,
at high volume, the sound can be a bit strained as
the mid does not have enough membrane area to pressure
the air at low frequencies.

With the CS2.4, especially with saxophone, the "blah"
produced lacks a bit of weight and at high volume,
the depends on the recording, the vocal can sound
a bit shrill especially if your electronics are sort
of in that direction. When you hear people complain about
the sound of Thiel speakers in general, I think this
is what they talk about. If you're used to speakers
which use larger mid driver (for example the Wilson
uses 6in and even 7in mid) that have a more relax and
warm mid range, you probably think the Thiel house
sound a bit on the bright side.

Anyway, I guess you cannot have it all. surprised :-)