Thiel Owners

Prof. just read a review of those 223K speakers tonight. Glad to know the 3.7 can compete. Afraid that any upgrade from my 3.5 will  only signify a difference and a major adjustment. Tom, just ordered a calibration mic and will do some testing with my Bryston in the large room next week. Stay tuned.

tomthiel -

I have owned 3.5's since 1979, and currently run four in a pseudo 5 channel system (bridged front L-R, for better stereo on non-surround-sound discs).  I also have a third equalizer since one or another of the channels on the first two alway seem to be noisy or intermittent.

My main interest is music, not film/video, and interestingly the four 3.5's practically eliminate standing waves, and with their 3db reinforcement, they also essentially require no subwoofer.  Plus the bass is smoother and quicker than on my pair of 2 2's, which are in my 2nd system.

I would DIE for a passive-part upgrade of these equalizers.  And from comments here, the same can be said true of many other 3.5 lovers.  Please keep it on your "to do" list.

ps.  BTW, I lived in Prospect, KY from late 1979 through early 1984, and recall being at a friends house when Jim auditioned his 3.0's or what I might have been early versions of the 3.5.  I lusted until I ran into the dealer demo pair I bought up in Burlington, VT in 1989.  So just know: I now lust for three upgraded external equalizers!  But I hope another six years don't go by until my lust is fulfilled.

Great discussion group!! Thanks @thieliste @ronkent for the information!
I have 2_2 first, then 7.2, now 3.7 all together, and find them different in personalities. I had once audition with 5i with Jeff Roland 7f mono but was not very impressed because the music was somehow "heavy" not "vivid" to my taste. I don't know if I misunderstood 5i's potential or not. But I like 7.2 more than 5i based on that experience.
I am very glad to hear the progress of upgrade kit of 3.7. I just had my mid-range drivers of 7.2 rebuilt by Rob. There were some materials degraded as time went by. The rebuilt was done. I will do soldering soon by myself, but kind of worrying about my soldering skill will mess up the 7.2 or not. Although Rob told me that's straight forward. And I use WBT solder, I don't know if it's ok.
One more interesting thing, I was told that Jim Thiel once said it would be better if someone got 2 pair of 7.2s to sit back to back (one face front  and one face wall). To eliminate reflex? Any idea?
Happy Weekend!

Harry, the CS3.5 was introduced in 1988, but its lineage goes straight back to the O3 in 1978, updated to the O3a (equalized) in 1979, O3b and then CS3 in 1983 and the 3.5 in 1988, numbered such as the 5th incarnation of the fundamental "3" design. They all share the same design goal of full-range, accurate in all spheres 10"x 3-way reference monitors. One core value, early on, was sensitivity / efficiency. The O1 and O2 came in at 93+dB @1w/1m. The hard facts of physics relegated efficiency to a lower rung on the survival ladder, which haunted the brand furthermore.

A simple passive part update for the stereo 3.5 EQ might be feasible, depending on how much space is available in the chassis.

Wayne, from the beginning, before the O1 in 1976, we experimented with many wave-form paradigms before settling on the wide-dispersion point source that became synonymous with Thiel. A highly intriguing form was the sound-field created by two back-to-back speakers forming a bi-pole radiator. I have run a pair of CS1.5s backed against my CS2 2s with wonderful results. The back-firing pair can get by with less evolved amplification.