I used this subwoofer to complement my Quad ESL 57 system, but Quads are no longer my main system. Raising cash to fund other projects.
I have extracted a blurb from a review posted on enjoythemusic:
And some notes on the unique design :
The two drivers are wired so they both push and both pull together. There is no compression behind the front driver because the rear driver is sucking the air from behind. The rear driver compresses the air behind it in the acoustic suspension box. Likewise, there is no compression from the rear driver when it pushes forward, because the air in front of it is moving into the void created by the forward moving front driver. Thus, the only effective compression recreating the sound wave comes from the front surface of the front driver. The S12 is essentially an open baffle monopole subwoofer, a patent pending design. The back wave of the front driver is nullified and the music comes from the front of the open baffle. Placing my head behind the front baffle of the speaker I experience a relative musical void, hearing only what is coming around the edge of the front baffle. The advantage of this design is the front driver works with greater transient speed and accuracy without having to deal with the compression on the back wave. The upper end of the subwoofer's range is intentionally rolled off at 24dB/octave.
Type: Subwoofer with 300-watt amplification
Drivers: Two 12-inch transducers (Danish Sound Technology)
Frequency Response: 27 Hz to 120 Hz (20Hz in-room)
Power: 300 watt RMS, BASH300S subwoofer amplifier
Adjustments: Variable frequency X-over, LFE input, phase, high level inputs
Weight: 52 lbs
Dimensions: 18 x 14 x 19 (HxWxD in inches)
I have tried to highlight some minor blemishes (that can be fixed with a sharpie) but there may be other minor ones I may have missed.
Functionally, the sub works great. If you are looking to integrate this your Tekton open baffles or any ob design or with the Quad 57s, these will work great as they are very musical and fast.
I'm located in the SF Bay Area so local pickup is very welcome. Please let me know if I can answer any questions.
I will ship CONUS at buyers expense but I will eat paypal fees.