Bass null in rectangular room - how to improve?

[ov_sjo]

Hi all

I am suffering quite a bad bass null from my primary viewing position in my home cinema. It's bugging me but I do understand the concepts as to why it's happening. The room is almost square and the primary viewing spot is centred, along with the TV. Sub is mounted in one corner and is of a tapped horn design.

There really isn't anywhere I could move the sub (and it look reasonable). If moving the sub could make a signification improvement (of which I am unsure of), then I could consider a different box. Originally I was going to have a 2 metre long version of this box under the TV with it venting towards the right of the floorplan (kitchen door, not shown).

Any thoughts?


Here is a diagram of the room:



Red = Primary viewing spot - worst perceived bass performance
Green = Good bass loading
Yellow = Somewhere inbetween

 

[ov_sjo]

Unfortunately no room for the sub up front in its current enclosure. It's got a four metre long path length!