Doctor M said:
The best way to do make an LFE track would probably be to strip the LFE track from the official 5.1 mix and sync it to the mix you'd like to use.

And that is actually what hairy_hen has done I believe. It is a proper lfe track.
For the comparisons I simply included also a derived lfe to put to to the test.

Ok, the methods were 1=active matrix, 2=farina, 3=V.I and the b's were with h_h's lfe... So pretty much what I expected :)

I can make these pretty quickly, 448kbps ac3 ok or is there need for a dts in 768 and/or 1536 kbps?