I believe only a Roku subwoofer will pair with a Roku TV. There should be no issue using a Roku TV and subwoofer with a soundbar of any brand. They won't "cancel" each other out as they really don't output the same frequencies. The TV will know the subwoofer is connected, so it will send to low bass to the sub and pass the rest on to the soundbar. That's the advantage of a Roku subwoofer on a Roku TV, it's smart enough to send the sounds where they belong.
Dan
Roku Community Streaming Expert
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