D-Sonics are cheap at $1k, Even better were the Red Dragon M500’s at S799 same Class-D module. At least they didn’t hide what they modules use last pic in the D-Sonic module." tricked up $100 Sanway subwoofer modules, that I saw for sale on Alibaba.
6 Moons:"The integrated Rowland Continuum S2, Red Dragon’s S500 beats with the same heart in a less high-end chassis for roughly half the price"
http://6moons.com/audioreviews2/reddragon/15.png
https://ibb.co/j4LhKGD Rowland Reasearch Contiuum 2
https://ibb.co/df2XBJL Sanway Subwoofer module
https://ibb.co/ckGmjKQ
https://ibb.co/2YXksxf
https://ibb.co/NNxqLsQ
Cheers George
6 Moons:"The integrated Rowland Continuum S2, Red Dragon’s S500 beats with the same heart in a less high-end chassis for roughly half the price"
http://6moons.com/audioreviews2/reddragon/15.png
https://ibb.co/j4LhKGD Rowland Reasearch Contiuum 2
https://ibb.co/df2XBJL Sanway Subwoofer module
https://ibb.co/ckGmjKQ
https://ibb.co/2YXksxf
https://ibb.co/NNxqLsQ
Cheers George