Crossover should normally be on "Bypass" as I'm guessing he set the crossover for the sub in the receiver to 80hz with your other speakers set to "small". You normally let the receiver manage the crossover.
The trim should NOT be on remote, it should be either Flat (most common), Half, or Full. If you read your manual it discusses each option. Generally, Flat is for the best flat response, however, some people with smaller rooms have used Half or Full.
You should invest in a cheap Radio Shack SPL meter, so you can make sure your speakers are calibrated to 75dB.
Randy
