Prologic, 3chlogic

[ljcii]

Hello, i feed my computer line-out to my home-theater amplifier.
It feeds stereo source, as such, if is it possible for me to get a 5.1 sound?
My amplifier only has prologic, 3schlogic and hall.
What i read is that the prologic only does it best with a dolby encoded sound while prologic II works with stereo source.

 

[iriverdude]

Music sounds horrible in Pro-Logic mode. Pro-Logic works with either analogue sources (VHS or TV broadcast) or digital (DVD) Pro-Logic II is updated version, and it also works with both systems, and has some music surround modes.

Some DSP's upscale stereo to 5.1 or 7.1 some are better than others. I would avoid using Pro-Logic and Hall DSP, try Pro-Logic II Music.

Pro-Logic (I or II) on stereo source is pretty standard, if a Pro-Logic logo pops up during the intro you can use Pro-Logic, if not switch to stereo as Pro-Logic processing on non Pro-Logic source can sound unusual, for example try it with a CD. You may notice rears dropping out audio and flicking back and forth.

 

[flashnolan]

iriverdude is correct in that music does not sound so good through Pro-Logic.

In a nutshell Pro-Logic basically takes a stereo signal and puts whatever is different between the two channels in your rear channel. It takes whatever is the same between the two channels in your front speaker. Typically anyone one speaking (voice) is mixed into both speakers equally so the center channel would be good placement (in a perfect world). Typically difference would be sounds you might want behind you (bullets, etc. in a perfect world).

What actually happens is a little different though. Especially with music the rear channels just sound echoy and weird (best way I can describe it). The center channel typically does a fair job of getting speach. Music gets a lot of DSP changes to it when run through Pro-Logic, and some of the stereo imagining is lost.I prefer the regular stereo mix when listening to music.

Pro-Logic II is a more advanced version of Pro-Logic.

 

[ljcii]

What about 3chlogic? I guess its time to change my receiver then.

 

[iriverdude]

Sounds like just mixing in a bit of left and right frequency around speech area then directing to the center. Sound expansion can be good but most don't do a good job, I'd listen in stereo. Lexicon Logic-7 is worth using, it's superior to Pro-Logic IIx

 

[necropimp]

now if you're talking about movies... there are ways

for one AC3 filter (which decodes both DD and DTS) under output format has options for dolby surround/prologic and prologic 2 mixdown which works fairly well
also some commercial DVD player software supports PL/PL2 mixdown as well

as far as dolby encoded signal vs stereo... what they mean is PL (and PL2) work best with surround signals that have been matrixed into a stereo signal they sound just fine played through a regular stereo setup but when run through a pro logic decoder the signal can be separated into multiple channels... feeding a normal stereo signal that doesn't have extra surround channels matrixed in results in a hit or miss (often miss) channel expansion and it's usually best to not bother in those situations

also...

if it's prologic 1 you won't get 5.1ch you'll get 4 ch (left, right, center, mono surround)
if it's prologic 2 you'll get 5ch

 

[virometal]

Have any of you guys messed with IIz yet? I have been wondering about the height channels.

 

[virometal]

Well the above inspired me to go to my fave HT dealer to check out a IIz set-up. The big Pearl Harbor set piece was the demo. Overall, the effect was more subtle than I imagined it. One caveat however, the receiver was mid-range Onkyo with Mirage omnipolars for the speakers, which aren't the best at imaging. I wondered about that choice.

Still, there were probably enough neat moments for those who lust after the latest. For example, the ground up shots were more obvious where one could hear the propellers spinning while passing overhead. I could imagine some good gaming applications as well.