Decoding AC3: Use SBLive Hardware or Intervideo Audio Decoder?

[Minako]

Hi there...

I recently got a SB Live 5.1. Everything working fine so far, but as I never have played with 5.1 sound before I have a (probably simple) question:

I can decode AC3 with Intervideo Audio Decoder (set to 5.1 speakers) or with SB Live Hardware (Intervideo set to SPDIF and SBLive set to AC3Decode). Which solution is better and why? My thoughts so far were:

1. CPU impact for decoding with Intervideo Audio Decoder should be quite minimal, so no argument for any of the two options.
2. Using Intervideo Audio Decoder I also can decode DTS (and other formats), which I suppose (correct me, if I am wrong) the SBLive does not do in hardware, so I would have to switch back to Intervideo Audio for any other format than AC3, if using SBLive to decode AC3.
3. The main thing: Is there any quality difference? Hard to hear, as I am not that experienced...

Any input on this is appreciated!

[ookzDVD]

@Chibi Jasmin,

I'm using both :

1. Enable the SPF-IF output (in the iviaudio.ax) and enable the
AC3 Decode from the SB, this is minimal CPU usage, but the
volume level is drop.

2. Enable the Analog output (in the iviaudio.ax) to 2 speaker
Dolby Digital 'cause the 5.1 output produce wrong channel
mapping in my system :( (Audigy+VXD+Inspire5300) due of
bad Audigy driver support,
this will use more CPU but the volume level is normal.

...about quality.. I think the first one is better than the second
at least for my ears ;)

PS. If you don't mind could you please test the analog output to 5.1
speaker and hear the sound. Make sure you use the latest iviaudio.ax
4.0.11.83 it will produce better sound IMHO.

Thank you.

[Minako]

Originally posted by ookzDVD
@Chibi Jasmin,

I'm using both :

1. Enable the SPF-IF output (in the iviaudio.ax) and enable the
AC3 Decode from the SB, this is minimal CPU usage, but the
volume level is drop.

2. Enable the Analog output (in the iviaudio.ax) to 2 speaker
Dolby Digital 'cause the 5.1 output produce wrong channel
mapping in my system :( (Audigy+VXD+Inspire5300) due of
bad Audigy driver support,
this will use more CPU but the volume level is normal.

...about quality.. I think the first one is better than the second
at least for my ears ;)

PS. If you don't mind could you please test the analog output to 5.1
speaker and hear the sound. Make sure you use the latest iviaudio.ax
4.0.11.83 it will produce better sound IMHO.

Thank you.

Well, I am using the 4.0.11.83 filter at the moment. It works fine (correct mapping) set to 5.1 speakers as well as set to spdif and soundcard to ac3decode. Can't spot much of a quality difference, but I am no experienced listener and didn't have much time to really 'hear' into this for longer...

[Minako]

Well, forget the question...I just read the decoding when set to spdif/ac3 decode is done by the sblive drivers using the cpu, not the soundcard hardware...