AC3 sound questions and issues

[civic00typer]

I have the Logitech Z-5450 wireless 5.1 surround sound system connected to my HTPC via 6ch out from a Creative X-FI Music and my XBOX 360 with an optical cable.

I was watching a DVD on the XBOX360 last night because the HTPC was down for repair. I noticed the digital sound was very vivid.. there was distinct sounds coming from each direction, the subwoofer was acting differently. There was alot more sound coming from the rear channels that I am typically used too. Previous to playing this DVD on the Xbox I would put on a XVID/DIVX with AC3 and use AC3 filter to decode the digital. There was rear channel affects, but didn't sound the same as using the optical cable from the 360. Is there something I am missing here? I feel as if the soundcard is simulating surround sound as if there were not 5 channels of sound. Maybe I am crazy.. any ideas?

 

[BBA]

I woould imagine a combination of incorrect AC3 filter settings and or your speaker balances set different from the X-Fi to the X-Box (set this in the THX console panel on the X-Fi) When you say 6 channel output on the X-Fi to your 5.1 speakers...are you sure you have everything set correctly? Do the sounds come from the correct place when you do the sound test?

But, I have never noticed a difference in AC3 from home stereo/DVD to PC DVD with the X-Fi and WinDVD.

 

[IanG]

It's either ac3 filter, or the creative drivers trying to apply some wizzy effects to make it sound 'better'. If you can, you'd be better relying on spdif (digital) out when watching movies and letting the receiver do the work instead of software.

 

[civic00typer]

There is no digital-out on the X-FI music. Furthermore when I say 6-ch out, I mean front speaker output, rear speaker output, and subwoofer/center output.. three cables. I have the AC3 filter set to 5.1 with subwoofer. I am not using WinDVD. I am playing DVD's encoded in the XVID format with AC3 sound. There are no special effects or balance issues in the THX control panel.

 

[phide]

There is no digital-out on the X-FI music.

You're certain of this? Seems strange considering that the Audigy 2 series all have a 1/8" digital out right on the card. Getting it to work is a bit tricky (mono 1/8" to RCA adaptor + 75ohm coaxial RCA cable), but it will work.

Another step backwards from Creative?

 

[jimmyb]

I agree with the other posters that the problem is probably related to an incorrectly set up ac3 decoder.

My system is set up so I can quickly jump back and forth between digital and analog out, and I can't hear any significant differences between them.