Because openjk devs silly. So you are using MBII client. It is a known issue and I already fixed it. The fix will come with the next MBII release.
For now I can only suggest to use jamp engine.
It's better experience if you select the 3rd arguement with quotes:
/bind b "voice_cmd bns_emplaced"
It's fine for the console but not for configs/scripts.
I just checked the code. I used to think game always counted up to 2 output channels, but seems like with EAX you can have as many as EAX can supports.
So instead of counting left and right volumes it just sends entity coordinates to EAX system and then the system plays it back in its own...
I have rewritten the whole sound engine (it took so much time to understand that all) and even added support to such formats as ogg and flac in the game and I know what I am talking about. The game outputs up to 2 channels, and if your rear speakers worked with all those technologies it's just...
Why do you need EAX if DirectSound works perfectly? If you look at the sound code then it counts everything the same including the surrounding positions for every channel (only 2 channels - nothing very "surround"). The only difference in how sounds get mixed and one more layer that EAX uses...
Try to play with jaMME client - it will definitely work even better than jamp and ojk.
Make a batch file with:
start jamme.exe +set fs_game MBII
And try to fix the ratio with mov_ratioFix 1/0, not with UI option.
Try com_affinity set to 0 (need to restart the game).
Try to reset all your settings to default and see if it fixed (just rename jampconfig.cfg to something else).