I experienced the same affect with my Duntech Sovereigns. I experimented with toe in, adjusting my listening position & changing the distance of the speaker from the rear wall. This problem is fixable with some experimenting with these three elements & retaining your present cable.
I would recommend that you check the Cardas Cable site for speaker & room setup. The information there is excellent. It will address all the factors you are working with. GOOD LUCK!
I would recommend that you check the Cardas Cable site for speaker & room setup. The information there is excellent. It will address all the factors you are working with. GOOD LUCK!