Found that AC3 5.1 CH makes a much richer sound than AC3 2CH, I tried to simulate the missing channels from the 2 existing:

For audio editing I'm using CoolEdit:

1. Made a vocal-cut thus giving front right/left ->FRL.wav
2. Adding an echo-chamber effect to FRL -> back right/left ->BRL.wav
3. taking FRL.wav, adding a Bass filter (BP from40-400Hz) and making it mono-> LFE.wav (Subwoofer channel).
4. Making the original wav to Mono and normalize it to 99%->Center -> Ce.wav

Than I used SoftEncode to make an 5.1 ac3 out of these wavs.So far so good, sounded really nice but:

Step 4 includes all the info from the FRL wav to, so the stereo width is somewhat reduced.Question:Is there any way to 'subtract' the stereo info first from the original wav before making it Center/Mono?
I tried this with channel mixer/mix paste but the result was not convincing at all.

PS:I know, I'm not making a real 5.1 Soundtrack, but with 6 speakers active, the sound is getting richer (beside the stereo problem from above)