Move your sub

Can you post the link to the video please?

It would seem that with the subs further out in the room they would need  to be played louder. 

ozzy

Your optimizing the bass time arrival if subs near plane loudspeakers occupy you could also place behind listener or on sides if physical distance is near same as seated listener is from both speakers and sub. You could keep subs physical distance correct for time integration and pursue boundary re-enforcement that most subs require. Or use multiple sub systems this gives better measured response in most rooms lower distortion increases system output.

Placement depends to some extent on what subs you are using.  With the Vandersteen 2wq subs that I use, I need to keep them near each speaker as the subs reproduce frequencies high enough to affect imaging.