Thiel CS7 experiment

I remember a dealer in Illinois recommending two pair placed in a back to back, bi-polar setup.  I don't recall if he was using Krell or ML amps.  I never heard the setup, but the dealer said it was his ultimate recommendation over Wilson, B&W or Infinity from that time.

Careful... those speakers drop to two ohms above 10Khz and stay below 4 ohms for most of the frequency range. Doubling the speakers on the amp terminal causes the amp to see half the CS7's load (1 ohm!!!) and can easily fry the tweeters on clipping. 

The low, flat impedance of Thiels is why they need a high power amplifier while at the same time are friendly to tube amps.

I have positioned them side-by-side, slightly toed in. I have a fairly large listening room, 23x26 feet, with a vaulted ceiling. I had thought that the imaging would be fuzzy; to the contrary, the stereo image is wide, deep, and precise instrument placement.

The Krell 350 MCx monoblocks have each two sets of output terminals. The amps may have to work a bit harder, but I don’t think it affects the speaker's impedance (or does it?). However, it’s a good point. I will check into that.

Your Krells are probably one of the few amps up to the task you’re asking of them.

If you play with the phase of the speakers as you have them set up you might be able to cancel inter-aural cross talk as done with Polk’s “SDA” arrangement. 

Another alternative would be  (and your rather large room could be quite helpful in this regard) to pull the main speakers well into the room with at least 8’ and preferably 10’ from the listening position and place the second pair directly behind the main speakers facing the opposite way as far as you can from the front wall (as seen from the listening position) maintaining correct phase. The somewhat unique time coherence of your Thiel’s are plus in this setup. This will energize the room much the same way that occurs at live events. Approximating an omni dispersion. Room reflections become much more critical in such an arrangement. Again your large room is quite advantageous for this.

Should you decide to try these options, I would be most interested in reading of your impressions, as I’m toying with the idea of doing similar things with my smaller  Thiel’s in a smaller room.