Dear @cundare2 : Thank's to post about the Perlisten and yes the manufacturer took care in its design and build quality level and according that design this subwoofer is a good unit.
However and always exist those " but " because in audio nothing is perfect.
The review and real time measurements that Audiolics made it showed that the reviewer never listened the Velodyne HGS 15 or 18 or even the 12 models where all those came with treated paper/pulp woofer material ( superior woofer material that any today one in that specific woofer designs. ) and not only that but he never measured the ( even today Velodyne DD models ) subwoofers with so low THD as the Velodyne units: 0.5% at below 20hz that's outperformed only by the 60K+ Magico unit ( o.4% ) that by " coincidence " uses treated paper for the woofers.
R.