How to connect Sub to Integrated Amp

Just bought a second hand Rotel RA-970bx integrated amp to finally seperate my stereo and home threatre system. Boy oh boy am I happy nowadays.

For now I've paired up my Rotel with my Cambridge Audio Azur 640c cdp and a pair of Paradigm Focus, which were originally my rear channels in my threatre setup. I'm quite happy with the setup, at lease until I can get the money to upgrade my speakers (thinking about the Paradigm Reference line already)

Being a pair of bookshelf speakers, the Focus can produce upper bass very well. But there are moments when I wish I can hook up my Paradigm PDR-10 sub, just for fun. The Rotel dosen't have a pre-out, only 2 pairs of tape out for recording. Can anyone advise me on the best way to hook up the sub?

Run the speaker outputs (the left and right speakers speaker wires from the amp) to the speaker inputs on the sub. Then from the sub connect another pair of speaker wires to the speaker outputs which will then go to your Paradigm Focus speaks. Adjust the crossover accordingly. Make sure it's at 100 hz or lower, whatever sounds best.