Ahh, you have 2wq not V2w... Here is the manual for that sub.... You need to use high-level outputs from the left and right speakers to the sub. Problem is that you will lose the LFE channel benefits from your receiver for watching movies, but should work great for music (once it is tuned).
https://www.vandersteen.com//media/files/Manuals/2wqmanual.pdf
https://www.vandersteen.com//media/files/Manuals/2wqmanual.pdf