The splitscreen mode in Doom on the XBLA is way too small. How can I make it larger to fill the screen better?

I'm playing it on XBox 360 and it's just 2 players. The screen size is maxed (10) and I've tried changing the display settings on the XBox from normal to widescreen but I see no difference (if there is a difference, it's negligible.) Is there a "fix" for this?