Thiel SS2 SmartSub and SI 1 Integrator

Five years in the making, Thiel’s new subwoofer system is like no other.

Johann Sebastian Bach, when asked why the rigidly structured fugue was his favorite compositional form, used to reply that within discipline there is great freedom. With the introduction of the groundbreaking Integrator and SmartSub system, Thiel Audio attempts to bring discipline to the historically unruly process of effectively incorporating a subwoofer into a music system. While the results are not quite as ordered as Thiel envisioned, they represent a colossal step forward. And true to Bach’s paradox, along with its imposition of structure, the new system brings unprecedented flexibility.

Why is it so difficult to seamlessly integrate a subwoofer into a music system? The primary culprit is that most subwoofers attack the problem backward. Designed in a vacuum, they are optimized for output, extension and, with any luck, sound quality. Even the best subs treat the issue of integration as an afterthought—deferred to a few crude, unpredictable back-panel controls.

Also conspiring against successful integration is the sheer variety of main speakers, which presents subwoofers the challenge of morphing into a cornucopia of shapes. Furthermore, today’s subs uniformly rely upon simple, passive filters to effect a transition to the main speakers. The resulting response curve can hope to approach—but can never achieve—the theoretically ideal straight line. Complicating matters still more, a subwoofer’s sound, like that of main speakers, varies by room location. The spot that best suits the sub may block optimal integration. Given these impediments, success can only be achieved through careful application of techniques like those described in “How to Set Up a Subwoofer” (The Perfect Vision, Issue 58, and online at www.avguide.com/download.jsp?review=1759) plus a fortuitous combination of room, sub, and main speakers.

Thiel’s inspired brainstorm was that by considering the main speakers first, and letting the subwoofer follow suit, it could attain superior integration consistently, irrespective of the associated main speakers and room. Implementing this concept meant: determining a means of quantifying the characteristics (and character) of the main speakers; creating a device to derive from that data a complementary subwoofer signal; building a subwoofer malleable enough to conform to virtually any environment; and enabling that subwoofer to deliver uniform response regardless of its room position, thereby allowing it to be placed wherever best serves the goal of integration. No wonder the project took five years to develop. I recently spent several months with the fruits of Thiel’s theories and labors in an effort to assess their sound and validity.

The front end of Thiel’s system is an entirely new component called the Integrator. Though at root a crossover, its digital user interface, on-board processor, and active circuitry distinguish it from conventional designs. (See sidebar for more technical details of both the Integrator and SmartSub.) The first step in using the Integrator is “telling it” about the system and main speakers so that it can customize a subwoofer signal that dovetails with that environment. In a laudable effort to eliminate the subjectivity and iterative trials that normally attend subwoofer setup, Thiel has striven mightily to make this a setand- forget process. The Integrator’s documentation entreats users to gather the necessary data from their main speaker’s manual (or from Thiel’s Web site), punch it in, and enjoy superb blend.

Would that this were truly possible. Unfortunately, perfect data is hard to come by. For instance, speaker manufacturers are often, shall we say, “optimistic” with respect to bass roll-off. Other required specifications, such as damping factor, sensitivity given a 2.83 volt signal (as opposed to the more commonly quoted and not necessarily equivalent one-watt input) and the main woofer’s absolute polarity (which can differ from the other drivers) are virtually never provided in owner manuals. The last point can really bite you, since the Integrator has no means of detecting or compensating for inverted main woofer polarity—the normally ubiquitous phase control is absent here.

Despite such lapses, and though it falls short of its set-and-forget target, the Integrator brings welcome structure and precision to the process of telling a subwoofer how to fit into its environment. In my experience, it works. The lack of complete and accurate main speaker information doesn’t mean consistently excellent results can’t be achieved. It simply behooves installers to experiment with the Integrator’s copious settings. As with a fugue, within its highly organized structure, the Integrator permits an unprecedented degree of flexibility and control. It simply provides more ways to adapt the subwoofer to its context than any other system.