Driving Thiels

I have had a pair of CS3.6's for 5 years now. I started with a Forte amp but the bass didn't seem right. Within about 6 months I ended up auditioning and buying a Pass Labs X350. With this amp the sound and soundstage are spectacular.

But just a few months ago, I had a problem with the right speaker dropping out. I traced it back to a cold solder joint on one of the speaker binding posts. That led me to buy a set of higher quality binding posts. (The factory posts are surprisingly cheap- i.e. lacking). Wow, what a difference, especially in the highs, the improved binding posts made. It's like a new pair of speakers for just a few dollars. It's hard to shut the system down now and walk away. I highly recommend this upgrade.

The Thiels are fast and totally disappear with the right electronics. I used planars for 14 years prior and it was a buddy of mine who had the 2 2's that finally prompted me to switch over to cones. The Thiels have the advantage of more punch than planars but with an equivalent soundstage. I guess the only drawback to the Thiels that I find is the few amplifiers (and some cost serious $$$) out there that can drive them proper.

I kind of hate to post this, though it's nothing I haven't said elsewhere. My friend Unsound and I have had this divergence of opinion before (as he knows :-) I believe he is a fan of sealed-box bass, and if you are, all Thiels past the 3.5 could be out of the picture. I certainly do not make the case that the 2.2 is an ideal speaker, there's lots of areas in which you could do better (typically for more money), but to my ears it has fewer weaknesses. In any case, try to listen the speakers in question yourself and make up your own mind...

Well, just to let you know where I'm coming from, I haven't heard the 3.5 in about 9 years. But at the time I bought my 2.2's (from the dealer, when they were still a current model and the 3.5's were already discontinued), I auditioned them both at length, at the same time in the same room with the same system (Classe amps, with and without the bass EQ, and the room size should have favored the 3.5). Despite my expectations for the bigger speaker going in (not to mention the encouragement of the dealer, who must have had his own preferences, or perhaps motives), I was somewhat surprised to find it really wasn't any contest regarding which model simply sounded higher in fidelity and more like real life, more compelling, convincing and stimulating.

Yes, the 3.5 is probably easier to drive (although the 2.2 in particular is not the beast some other Thiels can be, with nicely flat impedance and phase curves, the former not dipping below the upper 3's ohms, and average sensitivity of about 86-87dB). But across the range, especially in the mids and highs but including the bass, the 2.2 was more transparent, dynamic, neutral, open, and 'all of a piece' than the 3.5, which sounded opaque, colored, closed-in, and mechanical by comparison. Sure, the bass of the 3.5 reached a little lower with the EQ engaged, but its quality wasn't as defined or coherent IMO. I like Thiel's passive-radiator bass. And although it's certainly voiced 'richer' and isn't as extended on top, which might lead some to label the 2.2 as being 'bright' in comparison (I think it's actually more naturally-balanced), I found the 3.5 had a somewhat 'hard' quality to the treble which made listening less pleasant.

I don't know how Unsound came to his conclusion about the 3.5 having superior phase response across the spectrum, since all Thiels seem to have been spec'ed at +/-10 degrees in their passband, and other than the compensated bass alignment I don't see any technical reason for this assertion. The sonic evidence is that the 2.2 images and 'stages better, so its phase behavior's got to be just fine. It's my feeling that starting with the 3.6 and 2.2, Thiel's drivers got better in these series, and the cabinet designs took a step forward in terms of lowered diffraction and increased rigidity. Maybe the crossovers improved as well, I don't know, but Theils as a rule get a little better with every new generation that I've heard (although, with the exception of high-level dynamics, I don't think the leap from the 2.2 to the 2.3 was as great as from the 2 to the 2.2).

Who knows -- by year's end Unsound and I might both end up with 3.7's and we can put this thing to bed ;^)

Zaikesman as usual, presents a very fair and good argument. Jim Thiel himself thought the 2.2's superior to the 3.5's. I would even agree that the 3.5' have "a somewhat 'hard' quality to the treble". Proper associated gear can help. While the Classe' gear is a good (maybe even very good match) IMHO not the best for the 3.5's in this regard. Truth is, some recordings will demonstrate this short coming. My conclusion about superior phase response is due to the sealed box. I could be wrong here, but, I don't think ports or passive radiators can really maintain time and phase as well as a sealed box. The Thiel CS 5 and 5i were also sealed boxes and my all time favorite Thiels. The cost to properly drive them though is a very real hurdle. To be fair I should mention that the 3.5's midrange drivers can be a bit delicate, but, as Zaikesman has pointed out in a preivous post, Thiel is extremely cooperative in this regard. All in all I think Zaikesman and I really do agree on the how each of these speakers sound, we just have slightly different priorites. Yes the 3.7's look very interesting indeed, I fear that the costs may be prohibitive.