At different times, but not together, I have owned both the 3.6s and the Concentra Integrated Model 1 (not the newly released Model II) and I have some reservations about how well that combination may work together electronically. The Thiel 3.6 is a truly excellent speaker, and I made a huge mistake in selling it (i.e. sometimes an upgrade turns out to be a downgrade). However, because the impedance is often well below 4 ohms, it can present a very difficult load for an amplifier, depending partially of course upon how loud you play your system. The Concentra I ( as incidentally is also the case with the Levinson 383) does not always like to see lower impedance loads, and thus the combination of the two may be questionable in terms of extracting the maximum performance benefits. The Concentra is beautifully built, and its ergonomic feel is the best I have ever experienced in my 36 years as an audio hobbyist. Under more normal conditions, it sounds superb and I would absolutely agree with all of the positive comments I have read.
