Sonic Vortex from Beale Street Audio is described as a twist on a traditional ported enclosed design, and has some roots in transmission line technology. It is built into the integrated back box of the speakers, and is claimed to deliver significantly more bass.
This is achieved due to the main port of the enclosure being broken down into multiple sections called ‘fins’ that are tuned to spec.
The fins compress and move air at a high rate of speed without port noise and also add to cabinet rigidity. They deliver a flatter frequency response, a 6 to 9dB boost in the mid-lower bass ranges compared to sealed models.