Commenting on audiotroy’s post: I agree but with the provision that the mains have enough bass output to interact with the sub and help smooth the overall response of the room. However, my experience is that small speakers can often benefit from some type of high-pass arrangement. Being relieved of the low bass signal can result in the ability of a small speaker to play louder without strain while sounding more open at the same time.
To the OP: I do wonder about a couple of issues. It wouldn’t seem you could still use the Node in fixed output mode if you use it to drive your sub. Also, if you select the analogue output from the DAC as the source for the Node, you can’t listen to the Node as a streamer. The only signal you would get would be from another digital source feeding the DAC.
Of course, I may have misunderstood something. I do that from time to time.