I tried the Sierras and ended up with the 340SE's, the Sierras are way to tingly for me, dont get me wrong they sound very clean and clear, but the 340s were sooo warm, cozy, and just as clear {the Sierras enclosures were much better}, I can play the 340's a lot louder than the Sierras... The Sierras to me were tiring, while I can listen to the 340s all day....
When I have to adjust something, I put on cats in the cradle {harry chapin's, not gnr or ugly kid joes, lol} because I know the song in and out, and its super clean on cd... then I start at the factor default and write down my changes +5, -2, ect... Then compare your changes back and forth....
But first I would make sure the speakers are all correctly placed, phasing is all set, levels are all level, pos-neg is rite no ports up against a wall, no obvious room problems, ect...