Welcome, Jrain!
From many recommendations from others in the past when I first setup my M60's, I ended up setting my speakers to 'small' in the receiver, set the receiver's crossover to 80hz (try also 60hz if you have this option), then turned the sub's crossover all the way clockwise to get it out of the way. Then you can set the sub's volume to your liking. I've tried several other options, but I've found this was the optimal setting for both music and movies. Try experimenting though...you might like your sub set to 60hz with your M60's set to large. In the end, it's all up to you! Enjoy!
