I think i got the answer for this..
I am a new user.. I learn that your thread hasn't been answered for over than 6 months... I hope this answer will help.
If you go to the Now playing page of Realplayer, on the left hand top corner of the page, you will see the "Realplayer" along with it's logo. If you click the arrow to it's right, a pop-down menu appears. In that select the "tools" option. Another pop-down menu appears to it's right. The first option will be equaliser.
If your question has been answered already, I appologize for the late reply.