Positioning sound hardly in 3D

I would like to position sound in 3D the way that it is being heard only from one speaker of 5.1 set. To do this I’m setting source at (-1, 0, -1) and listener at (0, 0, 0) oriented at (0, 0, -1) and up (0, 1, 0). The effect is that sound is actually being heard in FL but also a little bit in FR (very quiet but existing). When I manipulate with coordinates, both of a source and listener, I manage to turn it down in FR but then it appears at rear left (still much quiter than in FL but noticeable). I’ve also tried to manipulate wih source direction, as well as max_distance, and reference_distance and a few more parameters but it does not help. I’ve read OpenAL and joal API and topics on this forum - no answer for me. It looks for me like there is no position in 3D space where sound is heard only from one speaker. Could you help me with this problem?

Best regards