Polk Magnifi Soundbar v2.11 - Dual Subwoofers

I am trying to connect two subwoofers to the same soundbar. One is the original subwoofer and the second is the same model subwoofer I got off of eBay. I have tried connecting both via bluetooth, but only one connects and the second just has the flashing light. I have tried one bluetooth and the second via the sub out on the soundbar and sub in on the subwoofer. As soon as I plug the audio cable into the soundbar sub out, it kills the bluetooth connection on the first subwoofer. Lastly, I tried connecting both subwoofers via audio cable using a y-adapter from the sub out on the soundbar. Neither subwoofer works with this configuration. Any thoughts or suggestions would be greatly appreciated!