Adelin, if I understand you correctly, one of your speakers might be out of phase.

Go back to putting them in the first position and try reversing the leads on ONE speaker only(!) and see if the bass is stronger one way or another.

If so, leave the speaker wire in the position that gives you more bass.

When the polarity of one speaker is reversed, you can lose bass because as one speaker's woofer(s) are moving out, the others are moving in...which can lead to them canceling each other out.

::::::: No disrespect to Axiom, but my favorite woofer is my yellow lab :::::::