Attenuation on "lowers the level of the analog audio outputs to prevent distortion" according to a review of the DVP-N999ES I read. This setting does not sound good on the 9000ES I use. Sounds lifeless and, not suprisingly, muted. My machine is stock (not for long though) and I also use the sharp/att off settings. It is nice though to have the option to fine tune it to what works best in one's own system.
Sorlowski, I've read many of your posts regarding your remorse at buying the Sony and I hope you've found something that you are satisfied with. Let it go man, we've all made puchases we regret. Life is too short to let a DVD player eat at your brain.