Couple of silly? suggestions bearing in mind the comments you made about the Exposure and bass???????
The bottom ports could be "partly" damped with half a cheap sponge shoved in sideways. Cost, under a quid and easily reversed if it goes too far. Fully blocking the port may mess up the midrange, although the bass will be better in a column like that - possibly.....
The other thing if the cables can be opened up enough, is to fit the positive speaker wire to the tweeter positive and the negative to bass negative, while leaving the straps in place. Sounds daft, may not make the tiniest bit of difference, but if the speaker cables can be opened apart enough it may be worth a try, just to humour me if nothing else
Obviously, PLEASE don't force the wire or the speaker sockets may just break. I cannot be held responsible for damaged caused thus
I can't go on and I can't go back, I don't feel so matter of fact,
I tried and tried to make good sense, What's the good to try it all again?