I currently have my Sanyo PLV-Z1 projector hooked up to a Scientic American Explorer 2000 Digital Cable box. The projector is 544p and I have had it almost six years. I'm thinking of upgrading, but if I didn't, would I see a better picture by switching to a HD cable box. I don't know a lot about the HD boxes, but would I be able to watch the HD channels on my 544p projector.