Quick question about Room Correction

Hi,
I have an 5.1 audio configuration and I play lots of stereo (two channels) music content (like mp3s and flacs).
By playing a 2.0 file, sound will come only from the front speakers (and subwoofer).
I found a way in listening stereo content to the all speakers by using the Room Correction feature found in the Enhancements tab.
The bad part is that I don't own a good microphone (my only microphone is the build in one), and I can't use any external microphones eigher (sound card has 3 jacks, wich by default, one is for microphone, but it's now used by the rear speakers)
When calibrating my speakers with the Room Correction, it puts some wrong values (i.e.: my front speakers have higher volume than the rear speakers, center has even higher volume than the front speakers).
So, my question is: is there a method (a registry hack or something) in manually selecting the settings for Room Correction? I want to have the value 1.0 for the all speakers.

Sorry for my bad english...

 

Nobody knows?