Thiel Owners

biannuzzi22

as above, consult Gary at Coherent Source Service.  Keep me posted on your rebuild experience.

Happy Listening!

I was wondering if anyone here has tried using two pairs of identical Thiels set up up with one pair back to back with the forward to the listener pair? If so, how did you set it up? How far from the back facing pair were they from the the wall they faced? Where they wired in phase (bi-polar) or out of phase (di-polar) from the forward to the listener pair? What did you notice? What did you prefer? Would you reccomend it?

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.