Then you don't get any LFE effects, because its not processing Dolby Digital or DTS. If you don't watch many movies made after 1990 or something you wont miss much, but for everything after that you do miss a lot of the experience.I'm using a NAD C658 which has separate sub outs if thats what you mean, but otherwise no I'm not using any 'surround processing'. As I said, I rarely watch movies with more than a stereo soundtrack anyway so I don't see much point ...