still don't understand how to set ultrasonic sub

[Creative]

What sub ? Are we referring to speakers (stereo) or a speaker (mono) ? You need to be certain that you have stereo sound.

If your asking me i'm using IYPS(dick) sub and yes i use stereo.Honestly i don't think hearing the sub is the problem, it's more due to resistance....if i couldn't hear the subs i wouldn't have gained anything at all...but i did,as little as it is, it counts.