down-mixing DTS, AC3 and AAC

Hi
I have a 2.1 Logitech Z323 speaker (by reading another topic in this forum and checking my cable i think its fake 2.1). but most of my movies are 5.1 or even 7.1 DTS or AC3 or AAC.

1- Does K-Lite Mega Codec Pack down-mix them to 2.1 properly when i play movies with K-Lite Mega Codec Pack's default Media Player Classic? should i do something or its done automatically? (i select "Stereo" in "Audio decoder output" in "Audio Configuration" window during installation)

2- if K-Lite Mega Codec Pack does this down-mix, from DTS, AC3 and AAC which one have better results in down-mixing? and which one does not work good?

3- Does it take effect if i sometimes use JetAudio 8.1.5.10314 instead of Media Player Classic?

I update K-Lite Mega Codec Pack regularly and i have 12.6.5 installed now.

and my last question: should i select "Include LFE" in "Audio Configuration" window during installation for better audio from my 2.1 speaker?

many many thanks in advance.

1. Selecting Stereo should be enough, assuming that your speaker configuration in the Sound settings of Windows Control Panel is already set to Stereo as well.
2. Downmixing is done after decoding and is same for any format.
3. Only if JetAudio uses DirectShow codecs. I have never used that player.

Using "Include LFE" depends on your personal taste and the quality of your speakers. You can easily adjust the sound settings with the Codec Tweak Tool. So just try it with the setting enabled and disabled and see what you like best. LFE is the subwoofer channel with the bass and low frequency sounds. So try it with a movie or song with such sounds.