Unable to hear back of the head sound effects

Technically, you need:

(1) Headphone + binaural recording.

(2) Crosstalk cancellation DSP like BACCH in a stereo system; (not Qsound that someone mentions)

(3) Multichannel speakers with multichannel recording.

Without these, the widest soundstage I have experienced from my 1st rig (or any other systems) is the vertical plane field up to my ears.

Yeah, way more info needed. 

Please clarify...are you listening to multi-channel or to stereo (2 channels, speakers in front, maybe a sub)?

It's on two channel stereo.  It is most easily heard on a pair of headphones.  It's not room reflection.

Binaural recordings do provide surround effects when listening with stereo headphones, but they still have headphone limitations.  The sound still seems tobe in one’s head to some extent, and location of sound from the rear is not as strong as sound from the front.  In any event, I don’t really care for hearing music coming from behind and prefer that the recordings use the additional imaging capability to create a more naturally enveloping soundfield with the instruments still located in front.

The BACCH processing did create the sense of a more open and enveloping soundfield, but was not quite as amazing as others have claimed.  This could be just my personal reaction, but I know others who were also not that impressed.