When I ran YPAO on my new Yamaha I noticed that the subwoofer was not used unless I used one of the presets. I like using the straight setting so the A770 decides per the source what speakers to use. There is a discussion on the Yamaha thread about this over on the AVS Forum. The experienced YPAO users reported that the auto scan more often the not configured the front R/L as large speakers. When it does this the software cuts out the subwoofer as not being nesessary. This is wrong for a home theater system, also for somebody like me who has large vintage speakers that sound awesome by themselves but sound even better when the load is taken off at the very bottom of their frequency response. The trick is to go into the setting and configure the front R/L as small speakers with this done the subwoofer is always active in the straight setting. You can also configure the low cutoff. Which, for now, I have it at 80Hz. With this done it is like opening a door sound wise you, and you maintain the YPAO dynamic volume control. Love this Yamaha!!!!!!!