Your good and have the right idea. Some amps calibrate to 75, others 80. The goal is to have all your speakers tweaked so they are equal at your main seating position. Usually each speaker takes from .5db or up to a few db, plus or minus, to even thm all out to say 75.

Also, don't be afraid to tweak a bit further to your liking. Once you get them set all perfectly equal, many people bump the center channel results up a db or two in order to get clearer dialog for TV and movies. If you find that you are always fiddling with the volume to hear speech better then lowering it again when loud sound effects occur, then this helps a lot and you can leave the remote on the coffee table where it belongs.

Other people like to bump their surrounds up a notch to highlight surround effects but too much and they get isolated to the speaker. Get it just right, and stuff blends and flies around the room, over walls, even your ceiling (see posts on "Master and Commander.")

With great power comes Awesome irresponsibility.