Its internal amp is for its own subwoofer ONLY, but if you use your own amp's full-range speaker-level outputs to feed two chanels entering the sub you can tag the 'floorstanders' onto the sub's speaker terminals as speaker wire extenders. Your amp will be powering the floor units.
I'd keep the sub separate and feed it LFE only if it was mine.
Answers & Comments
What 'floorstanders'?
Its internal amp is for its own subwoofer ONLY, but if you use your own amp's full-range speaker-level outputs to feed two chanels entering the sub you can tag the 'floorstanders' onto the sub's speaker terminals as speaker wire extenders. Your amp will be powering the floor units.
I'd keep the sub separate and feed it LFE only if it was mine.