I just have it set to 'Subwoofer yes' and LFE only. It would not surprise me if something odd was going on. The Sherwood has had many buggy bass management issues.
Last night I watched 'Kingdom of Heaven ' with them set to Large.(unbeknownst to me because I thought I had set them back to small. I guess I did not because when I looked at it this morning they were still on Large.)
Anyhoo..The bass was rockin' the house.???