Thanks for the quick reply!

I'll be more specific:
If I take the cable going to the sub and connect it to the LFE-out of my processor, the sub works great. If I then move that cable to the LFE-out of the SMS and use another cable from the processor LFE-out to the SMS LFE-in, there is no signal to the sub. I have tried 3 cables and metered this last one.

BTW, it all worked at first. Am I missing something?

Thanks again.