I have all my speakers set to large, but I have an Outlaw ICBM-1 bass manager between an Onkyo 797 (used as a processor/preamp) and an Anthem PVA-5 amplifier. I use the stereo subwoofer outs from the Outlaw (Klipsch LF10 and Velodyne CHT10). M60 like front speakers and M50 like side surrounds set at 60 Hz.

Works very nicely.

Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.