Terz:
I would put the sub distance back to where it was.

What's happening is that because there's circuitry and amplification in the sub, the signal gets slowed down a bit more than if it were just a straight connection from the jacks in the back to the cone.

The fact that your Denon "hears" the signal taking a bit longer to get to the mic is being interpreted as the sub being further away.

So really, leaving that distance set at the "further" setting that Audyssey found was indeed correct to make up for that slight delay.

::::::: No disrespect to Axiom, but my favorite woofer is my yellow lab :::::::