I recently changed from Radioshack Megacable 12AWG (25 ft) to Kimber Kable 8TC (8 ft). While the change definitely gave me clearer presentation, I would say the sound stage (at least for my case) was more to do with how far the two front speakers were apart. I did lots of experiments with the speaker placements, and the sound stage was clearly related with the speaker distance. I do toe-in the speakers, which is for better focus.
Just to see how the sound stage changes, you can put your two speakers near the side walls. This will cause many other problems but to see if how big sound stage you can get.
If you haven't done so yet, I'd recommend you to check out Audio Asylum FAQ. Go to http://www.audioasylum.com/, and then at the top right corner there is "Audio Answers". Click it to go to "Speaker Positioning Resources".
Just to see how the sound stage changes, you can put your two speakers near the side walls. This will cause many other problems but to see if how big sound stage you can get.
If you haven't done so yet, I'd recommend you to check out Audio Asylum FAQ. Go to http://www.audioasylum.com/, and then at the top right corner there is "Audio Answers". Click it to go to "Speaker Positioning Resources".