"The effects of the third category of problems are well known. Almost every subwoofer installation is plagued by response irregularities that are habitually attributed to 'room resonances'. A study of the situation reveals that the majority of serious problems are not, in fact, strictly speaking, room resonance problems, but rather boundary problems of cancellation and reinforcement. Even though the effects on performance are similar, the distinction is important because it indicates a quite different type of solution. Room resonance problems cannot really be solved by any method other than physically changing the proportions and size of the room. Further, even mitigating the effects can only be accomplished for one listener location, with the usual result of worsening the problems for other locations. And implementing such mitigations requires sonic measurements in the listening room with microphones and adjustable equalizers."

"Boundary problems are fundamentally and importantly different. Boundary effects are substantially consistent throughout the room and therefore corrections are improvements for all locations. Also, the effects of nearby boundaries are predictable and therefore can be corrected without measurements. Such a built-in system of boundary compensation is an important aspect of the Thiel Smart Sub system."

Thiel goes on to say that there are three boundary effect variables that once properly addressed, minimize or eliminate the associated problems. They are degree of reinforcement, cancellation frequency and cancellation severity. Because the distances to adjacent walls directly affect these variables, they can be accurately compensated for if that distance is known. By incorporating two sets of independently adjustable compensation values, the SS2 can be accurately calibrated to virtually any placement. In practice, that's as easy as dialing in the distance from the nearest two walls on the LED display located on the rear of the SS2. The SS2 performs all the calculations and makes its own automatic adjustments in the analog domain. If the hallmark of high technology is transparency to the final user, then the SS2 indeed meets that elusive criterion. In fact, Thiel's just won two patents on the technology involved. It's truly plug'n'play simplicity that takes 98% of the mystery out of subwoofer use. All you have to do is dial in the subwoofer's volume level, which I found incredibly easy to do. In fact, the SS2 arrived out of the box set up so perfectly for my room and me that moving its digitally actuated volume control (there are none of the rotary controls usually found on subs) caused the bass to obviously go out of true.

The PX02 Passive Crossover
To facilitate an optimum blend between subwoofer and speakers, Thiel sent along the PCS-specific passive crossover. This all-aluminum box (as sturdy as the speakers and sub) measures 7 inches wide by 2 inches tall by 6.5 inches deep. The PX02's rear is adorned with a single XLR output and two pairs of the sexier binding posts that I missed on the PCS speakers. These binding posts are the unit's high-level inputs. The PX02 is designed to take the speaker level output from an amplifier, send it through its low pass filter and forward the resultant signal to the SS2 SmartSub via a balanced interconnect (not supplied). My review PX02 was designed specifically for use with the PCS loudspeakers and thus incorporates the appropriate low-pass filter values. For those wishing to supplement other Thiel speakers, the company makes complimentary passive crossovers for all of their current-production speakers.

The Proof Is In The Listening
I found both the PCS monitors and the SS2 deserving of separate and distinct reviews. However, I also found that once mated to one another, they performed so well together that it seemed equally logical to approach their evaluation in tandem and as a system. So for the most part, that's what I'm going to do.

I will say that my initial listening was done to the PCS monitors without a subwoofer and that I was pleased by their performance. Thiel specs the speakers' reach to only 50Hz but I believe that a lot of people would be surprised by just how much bass that buys you. On their own, these monitors are extremely well balanced and offer enough LF extension to be considered a complete loudspeaker, albeit one in the bass-limited class. At $3,000/pair, they aren't cheap but neither do they approach the stratospheric prices of certain other stand-mounted designs. For their asking price, they deliver an unusual amount of across-the-board transparency, detail and musicality. The PCS monitors are linear and present a personality that has its roots firmly planted in the high-science and engineering camp. That is to say, they exhibit absolutely no euphonic colorations nor strategically implemented frequency response peaks or dips that would result in appearances of supernatural speed, detail or romantic sweetness. I could detect no bass or lower midrange anomalies designed to make the speaker sound bigger than it is. Neither do they betray a bogus attempt at artificial warmth. It's as though the PCS was originally conceived to be part of a larger system utilizing a subwoofer (which Thiel did not have on the market when the PCS was introduced) and any attempts to bastardize its performance would have led to major compromises once it was mated with that subwoofer.

Where imaging is concerned, the PCS performs like any speaker of its genre - it images extremely well and with sharply delineated performers and excellent focus. I found soundstaging characteristics pretty good but not quite up to the standard set when I introduced the SS2 SmartSub into the system.

By now it's been widely enough reported that one of the lesser-anticipated benefits of quality subwoofing is the added degree of space it brings to the soundstage. There's a tremendous amount of spatial information hidden in those low frequencies. Before you even get to those big pipe organ recordings (which I eventually did), you can already appreciate a good subwoofer with chamber music, for instance, as you suddenly become aware of the original recording venue. Of course, true full range bass extension has other privileges as well and once I got used to the PCS/SS2 package, I found it pretty difficult to go back.

One of the reasons that small speakers still manage to sound acceptable down low is that even while they omit the very lowest

fundamentals emitted by large bass-producing instruments, the harmonics of those fundamental remain well within the grasp of the speaker and the human ear/brain mechanism by tendency seems to latch onto that harmonic structure and fill in the missing information. That's a pretty neat trick of computing which our brains perform like a virus scan in the background. However, this illusion doesn't even come close to filling in those fundamentals as well as the SS2 does. Not only does the soundstage expand but the music gains density and gravitas that you didn't even imagine possible without replacing the speakers. And then there's all that visceral bass energy conducted throughout the room, across the floor, into your chair and into your body. That's exactly what the SS2 brought to my room.