Hi, I too have the 805
You can change the equilzer on the 805, I did with my setup. If you do change it, you will only be changing the equilizer. The SP distance and levels that Audyssey has previously set will be unchanged. I found the Audyssey calibration to be a little muddy so I did some minor tweaking. I say go for it, if you don't like the sound of it, then just change the equilizer setting back to "Audyssey".