It seems my Acurus ACT-3 operates quite differently from most receivers. I run all 4 La Scalas with a crossover at 70 Hz to both VMPS Larger Subwoofers. The sub loudness settings are somewhat different in stereo, DD and DTS, but the crossover point is the same and the subs work in all modes. Originally, I ran the La Scalas full range and the subs rolled in below 50 Hz. It was great! However, through experimentation, 70 Hz sounds better and has more impact, or thump. My front La Scalas don't sit in a corner or near a wall.
John