In the early years, Thiel considered reflex bass as a necessary cost-compromise only for entry level products ie home theater and models 1 and 2. When it came time to replace the CS3.5 with the 3.6, I resisted going to reflex bass in the 3, which had always embodied our highest aspirations. The equalizer needed improvements which were judged too expensive for the target price. Fair enough. I lobbied (unsuccessfully) for a modified CS5 style bass with overall system impedance high enough such that the falling bass impedance could stay above 4 ohms. The prevailing argument was that ports (a performance step down from our passive radiators) were ubiquitous, even in speakers selling in $6 figures.
Nonetheless, our foundational commitment to time-alignment was compromised. Reflex puts the deepest fundamentals a full cycle behind the action. As duramax has said " the bass player is out in the parking lot". Thiel’s reflex bass is implemented as well as I’ve seen at any price, but it does unavoidably delay the deep bass.
So you know, we have prototyped an equalizer using Jim’s excellent topology but adding regulation and more beef to the power supply, higher grade caps and metal film resistors - while still remaining affordable.
Another problem with straight bass (non-reflex) is that very large driver excursions are required, which works against our underhung, low distortion motors. My assessment is that if push comes to shove, an overhung woofer motor is far better aligned with Thiel values than is the reflex timing error.
All of the upgrade technologies we are developing in the SCS4 workhorse will be applicable to all Real Thiel speakers. The 7.2s weak link is a 400uF bank of electrolytic caps in a parallel notch filter. Although considered less audible than series-feed circuitry, shunt filters are audible. I have developed two fixes. 4x100uF film caps, which is expensive and large enough to only apply to an outboard crossover. But another fix is to replace the 4 x 100uF electrolytics with 8x50uF higher grade Els in a bundled layout concentric around a new Golden Cascade 1uF bypass with its coaxial sections decreasing to 0.015uF. That’s the minimus value we landed on and used in the CS3, 3.5, 2, 1 and 1.2. The cost and footprint of this fix is accessible for an inboard crossover. Lovely improvement.
Regarding duramax’s silver cabling. I have also found silver to be magnificent and free of any excess brightness - depending on design - many elements are in play in cables. I have some custom silver plated copper wire that plugs right into my BiFlow topology. The extra cost of silver is significant, but my geometry has cost-effective manufacturability. So a silver option is on the radar.
Our behind-the-scenes rate of progress has been called ’glacial’. It’s really slow, but also quite large.
