If you have to put your s1's close to a wall and you get too much bass back off the bass a little or simply tilt them back. That is if they are on the floor or table. if they are on stands then turn down the bass a little and add a little treble. Just enough to clear it up. Usually only you are hearing too much bass. Out front the sound clears up so turning bass down too much is not a good thing. Test by turning on a style and walk out front and see how it sounds. always the best way.
MEL