I have not heard a sub built by the manufacturer themselves, however I have built a number of subs using Adire drivers (Shiva, Tempest and Tumult). In terms of quality the Shiva is around the same quality as the entry level SVS TC Sounds driver, the Tempest is a 15" version of the Shiva, the Tumult is their best driver, on a par with a pair of the SVS Ultra drivers in terms of displacement but with slightly lower distortion levels at high output due their flatter BL curve.