Samson,

As JohnK and others have indicated, a few inches from the port to the wall is all you need to let the deep bass pressure escape into the room.

But what is far more influential than the port-to-wall distance is the actual locaton of the sub (any sub) relative to the corner and intersecting room boundaries. If the deep bass is too "boomy" or "one-note", you may want to move it away from the corner along one wall to reduce the bass reinforcement that the corner provides.

Regards,

Alan Lofft,
Axiom Resident Expert (Retired)