Thiel Owners

unsound - you or someone on this forum may have the reference where Jim suggested that arrangement. What I do remember is that his response was a reaction, not a serious suggestion.

I have tried that setup for on-site recording playback monitors with both the CS5i and CS7.2. Large rooms, placement problems, need for large sweet-spot, plenty of big amplification on site. I put a pair of CS2.2s behind the main out-facing speakers. Speakers were tight back to back, duct-taped to avoid buzzing. BiPolar (same polarity) won.

I liked the more powerful, room-filling deep bass with reduced eigenmodes.  There was also an increase in overall sense of spaciousness. But the 'sound' was less true to our remembered live-sound sources (in the same space, in the same session) as well as our headphone reference. In special circumstances it may have some appeal; but it requires deep pockets to implement. I would not recommend it for normal folks with pockets of typical Thiel users.

@tomthiel , Thank you for your prompt response, I am familiar with that response from Jim Thiel with regard to bi-amping CS 5’s. However it was this post:

Audiogon Discussion Forum from @erik_squires that got me thinking, as well as that it might be a consideration for me with CS 3.5s. I also seem to recall that @duramax747 had two pairs of CS 5i’s.

I’m not surprised that you prefered the bi-polar to di-polar layout, as to my ears di-polar speakers more often than not present a lumpy frequency response. I would imagine that having back to back pairs could even out in room bass response. The only bi-polar speakers I can recall, were some highly regarded (though I was unimpressed) Mirage models. They were however not symetrical front to rear in driver location or cross-over points.

I would have imagined that having identical speakers back to back would have been more advantageous? What would be the recommended distance from the facing wall of the backwards from listener pair of speakers? What would the ramifications of using the amps with bi-wiring capabilites on each front to back channels vs. dedicated channel amplification be?

unsound - I have remembered that I also tried 'your' configuration in my Middle Crossing studio where we had a fairly large, well-proportioned, well tweaked room. I believe that duramax has two pair of CS5is, but I'm not aware that he has done this experiment. I had two pairs of CS2.2s, back to back and unitized, each channel driven by a stereo Classé DR9, one channel driving each speaker, with another identical amp driving the other two back to back speakers.

Side-step to Thiel's conceptual model - to have each channel act as much as possible like an omni-directional microphone. That causes extra trouble for set-up because the wide dispersion interacts more with the room than narrow dispersion designs. Adding the back-firing speaker exacerbates that set of problems.

On the other hand, the psycho-acoustics favor the 2-speaker arrangement since they are driving the room (as seen and aurally interpreted by the listener) more like real 3D instruments in that room, more like that mythical omni mic. This configuration will add more power to the sides and back than to the front-firing energy. So, more space and/or critical wall treatment will be needed.

My room was 16' wide x 24' long with porous-resistive walls that acted like a much larger room. In that room my standard spacing put 5' from the front (solid) wall to the tweeter plates. Since the back wall was porous, I could pull the speakers into the room without bounce problems from the back wall. I recall bringing them forward to around 9'. I lacked room to spread them wider than their 9' ctr to ctr. That tuning operation is a combination of physical experimentation and experientially gathered positioning data from decades of setup work. Tedium that pays dividends.

Regarding bi-wiring. I put considerable effort into that proposition due to its popularity in the field. I dislike it, like Jim disliked it. In Thiel's coherent milieu, some bonded point must be assumed as all the circuitry and drivers act as a unified system from top to bottom. The only point that we get full control of that unified system is with all drivers driven from a single point of entry. I also found that in the real world of cost-benefit, a 'better' set of cables provides more value than two 'lesser' sets. But even if you could get two identical 'better' sets, their working parameters would be different than those of the speaker as designed due to their considerably longer length and reflection parameters. My best results (half-century and counting) have been with single runs from a stereo channel (not bridged) through a single pair of speaker cables. By the way, in those trials my best bi-wire results were with internally bi-wire in the same cable rather than separate home runs between amp and speaker.

Phase-time coherent speakers like Dunlavy, Thiel and Vandersteen may present a best case scenario for this bi-polar proposition. Their radiation field is already propagating in phase and in time from top to bottom as though it were a single driver. Another fully integrated radiating field would form the other half of a spherical radiation field. You may know that Jim was contemplating a spherical solution when he died. Among our pre-Thiel Audio experiments, we all loved the spherical driver he made out of dozens of headphone drivers. But as green 20-somethings pursuing that idea was a bridge too far. 

Hi all.  New to this thread - really because I had no idea this existed, but glad it does.  I'm the (VERY) proud owner of several (some past) pairs of Thiel speakers (1.2, 1.6, 2, 2.2, 2.3 and 2.4's).  I fell in love with Thiel's since the first day I listened to them when I mistakenly walked into Omni Sound in Addison (Dallas sub) thinking it was just another stereo store I hadn't been to in about 1986/7.  Ended up buying a pair of 1.2's and a B&K ST-140 and still have both.  At some point I gave away the 2's and the 2.2's (for very little $) because the persons that I gave these to were listening to crap speakers but had good electronics (one had Mac stuff they other had something else just don't remember).

I recently acquired a nice pair of 2.4's and have been "fixing" them as the previous owner had no idea there were holes in the drivers, the bucking mags fell off of the woofers and various other abnormal things - but thought they sounded just fine - I think his hearing aids were on the blink personally.  Anyway, Rob, and now Gary, have helped me tremendously though the years and now helping me with these 2.4's.  Gary has rebuilt the coax drivers, helped with various parts and recently acquired a set of the Clarity Caps used in the 2.4SE's to bring mine up to the latest spec - or so I thought until I began reading this post over the past week or so.

In the process of gluing the bucking mags back onto the woofers and going to replace the caps in the coax section of the xover, but thought, what else should I replace on the coax board since I'm basically going to need to move some stuff around.

Being a noob to the thread - what else should I (or MUST) replace/upgrade that will make these already gorgeously sounding speakers even better.  Not really concerned about cost as long as I'm not spending thousands (but replacing these with something better is moving into the $10,000-15,000 category anyway) and open to any and all suggestions - I sort of an engineer hack to begin with so fire away.