Would a crossover do it for me ?

hi everyone - I have a home stereo set up where I would like to add a Yorkville Pulse 600 watt powered sub which I have lying around(ps2310p). I have a set of advent speakers, and I would like to send lows to the sub and mids/highs to the Advents. The problem is that the sub is configured internally in such a way that it usually runs with full range speakers and doesn't affect how the full range speakers work (it sends a full range signal to the speakers and it amplifies the lows. This sounds good on paper but for a house, it requires too much volume. I don't want my advents to be screaming for nothing - this type of sub is usually used by a band or maybe in a dj set up). In my case, I'd like to send the lows only to the sub and no lows to my advents. Is there anyone here that is familiar with this sub or has done this ? I have a few more questions, if someone could answer them - thanks, Terry.

You need to add a high pass filter for the Advents. You can probably get a passive filter from a car stereo guy that would be cheap or try Parts Express. Try crossing over at about 100hz. You would then adjust the bass level to match the level of the Advents with the control on the powered woofer