Hello, is there any "official" solution to this matter yet?
For the past half an year I've been using kX 3538a with an Audigy 2 (6.1) and its 7 analog outputs. At some point last year I searched the forum but didn't find a complete solution for 6.1/7.1 upmix.
For the time being, when I want to upmix 2.0/5.1 to 6.1 I do this:
insert a mono-mix between the Surrounder+ and the epilog like that:
sL, sR --> 50/50 mono mix --> k2 I2S 2 Left
1. Thus the sCenter1 output is completely lost for software that support it.
2. I have noticed that when playing stereo music with that 5.1->6.1 upmix enbled, the Front center and the Rear center channels sound very distorted at some frequencies. There is noise and crackle coming mainly from the Front center. But the Front center has nothing to do with the upmix!?
Even more strange: if I mute the Rear center OR mute the Rear left/right, che crackle disappears. Muting the Front left/right has no effect. Wierd...
Back to 1.: When I run a game with positional sound or when I watch a movie with PowerDVD, (which also can upmix to 6.1), I have to remove the mono mix and revert to
sCenter1 --> k2 I2S 2 Left
Today I searched the forum again hoping to find something more. I saw that several test versions have come out, so I uninstalled and deleted everything, then rebooted and installed 3538c, 3538g and 3538h as described in another thread. There seems to be no difference.
Hello, Rogacz. By the threads I read, I can tell that you have been fighting the same problem for a long time. I tried the two mono mixes you suggested above but no sound came out of the rear center while playing an mp3. Honestly, I don't understand at all what these two mono mixes do

Could you explain them to me (maybe in private)? Perhaps you have done some other tweaks to the DSP?
In brief, my purpose is to have clear 6.1 sound at all times:
- to listen to stereo sources (audio/movies/games) upmixed to 6.1 and without distortion;
- to watch ac3/dts movies upmixed to 6.1 using the (still 5.1) ac3 filter;
- to have direct 6.1 output in games that support positional sound, so that I can tell when I've been shot from behind

If there is a driver version or DSP configuration which can do this automatically, please let me know.
Apart from that small inconvenience, I am very pleased with kX and am very grateful to the author(s)!