On-board SoundMax Trouble...

  • Thread starter Thread starter The Berzerker
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The Berzerker

My ASUS P4S800D has onboard sound via the 'ADI AD11980 SoundMAX AC '97 audio
codec'. I'm trying to use the 5.1 output functionality.... but it's not
working.

I've connected a coax lead to the SPDIF port, and set the soundmax config to
a 5.1 speaker setup... however, my decoder still only receives a stereo
signal. So, I'm totally lost as of what to do...

I can't just select 5.1 on my decoder, if it receives a 5.1 signal, it does
it itself, if there's no 5.1 signal, it'll just show up as stereo.

I hope someone can help, thanks.
 
"The said:
My ASUS P4S800D has onboard sound via the 'ADI AD11980 SoundMAX AC '97 audio
codec'. I'm trying to use the 5.1 output functionality.... but it's not
working.

I've connected a coax lead to the SPDIF port, and set the soundmax config to
a 5.1 speaker setup... however, my decoder still only receives a stereo
signal. So, I'm totally lost as of what to do...

I can't just select 5.1 on my decoder, if it receives a 5.1 signal, it does
it itself, if there's no 5.1 signal, it'll just show up as stereo.

I hope someone can help, thanks.
Click to expand...

SPDIF is two channels (stereo). Dolby Digital is a special encoding
that squeezes 5.1 content into those stereo channels. To create
Dolby Digital requires a license from Dolby Labs, so you won't find
too many computer setups with the ability to create Dolby Digital
content in real time.

The best way to test that your SPDIF can carry Dolby Digital, is
to use your DVD player on the computer, to play a movie which has
the sound track encoded in Dolby Digital. The DVD software will
simply pass the audio samples, with their special encoding,
directly to the SPDIF interface. Your receiver should then play
the movie soundtrack in 5.1.

Very little other content will do this, unless the content provider
paid for a license. There are probably software programs for
creating Dolby Digital content from multichannel source, but expect
them to be expensive.

The only hardware solution I know of, is the Nvidia Nforce2 MCP-T
Southbridge. It has a digital signal processing core in silicon,
and Nvidia has a license from Dolby, to create 5.1 content suitable
for playing on the SPDIF. That means someone with a A7N8X-E Deluxe
can play 5.1 via a hardware route. Other chipsets don't have that
capability.

HTH,
Paul
 
Paul said:
SPDIF is two channels (stereo). Dolby Digital is a special encoding
that squeezes 5.1 content into those stereo channels. To create
Dolby Digital requires a license from Dolby Labs, so you won't find
too many computer setups with the ability to create Dolby Digital
content in real time.

The best way to test that your SPDIF can carry Dolby Digital, is
to use your DVD player on the computer, to play a movie which has
the sound track encoded in Dolby Digital. The DVD software will
simply pass the audio samples, with their special encoding,
directly to the SPDIF interface. Your receiver should then play
the movie soundtrack in 5.1.

Very little other content will do this, unless the content provider
paid for a license. There are probably software programs for
creating Dolby Digital content from multichannel source, but expect
them to be expensive.

The only hardware solution I know of, is the Nvidia Nforce2 MCP-T
Southbridge. It has a digital signal processing core in silicon,
and Nvidia has a license from Dolby, to create 5.1 content suitable
for playing on the SPDIF. That means someone with a A7N8X-E Deluxe
can play 5.1 via a hardware route. Other chipsets don't have that
capability.

HTH,
Paul
Click to expand...

Thanks Paul, that's fantastic. By selecting use SPDIF in powerdvd's options
(something I had overlooked) I now receive a 5.1 signal, however, I'm still
a little lost.

While the dvd being in 5.1 is dandy, I really want to use the 5.1 system for
games. However, I still cannot receive anything other than a stereo signal
(outside of powerdvd). I'm trying on both painkiller and Doom 3, both games
being 5.1 capable. You have any ideas? I'm almost certain that it should be
outputting a 5.1 signal all the time, because there's even a test utility in
the soundmax setup panel..... it rotates static noise around the speakers,
but because the decoder is still getting stereo, you don't hear the rear
speakers. There must just be a freakin' check box laying around on my PC
that'll enable the use of the SPDIF port all the time.

You've done great so far, any other ideas???

Chris
 
My manual states you also need to use the dual purpose jacks previously
assigned to line in/ line out/mic etc to achieve the other 3 channels
Line in is bass/center, line out is front and mic is rear..
 
Mechanic said:
My manual states you also need to use the dual purpose jacks previously
assigned to line in/ line out/mic etc to achieve the other 3 channels
Line in is bass/center, line out is front and mic is rear..
Click to expand...

I believe this is one possible way, but it won't work on my setup. My
speakers do not connect via jack plugs... they use the same type of
connection that is requried to connect to the SPDIF port (a coax cable fits
it). Anyway, I'd much prefer a straight up connection to my home theatre
unit (So I can still have other devices using it!)

It's already been proven that my SPDIF port is capable of dishing out 5.1
sound (my powerdvd experiment posted earlier). So I just need some
experienced guy to tell me what to do..... Soundmax haven't got back to me.
 
The said:
I believe this is one possible way, but it won't work on my setup. My
speakers do not connect via jack plugs... they use the same type of
connection that is requried to connect to the SPDIF port (a coax cable fits
it). Anyway, I'd much prefer a straight up connection to my home theatre
unit (So I can still have other devices using it!)

It's already been proven that my SPDIF port is capable of dishing out 5.1
sound (my powerdvd experiment posted earlier). So I just need some
experienced guy to tell me what to do..... Soundmax haven't got back to me.
Click to expand...
I think you'll find that your games support 5.1 output through the
speaker jacks (using 3 or 4 of the 1.25mm audio connectors) and that in
order to get *Dolby* 5.1, the game would have to export S/PDIF PCM
streams. DVDs work because the audio is pre-encoded in this format and
your PC simply passes the streams on to your home theater receiver,
which decodes the audio tracks into Dolby Digital 5.1 or DTS.
Pre-encoded Dolby 5.1 PCM isn't the case with most software, and so most
programs, games included, will still output standard stereo audio on the
digital-out line. Of course, I could be very wrong (and I'd like to be,
because I too have a nice home theater system hooked up to my PC and
getting all-aroudn 5.1 would be awesome), but I think the only way to
get sound out of your rear HT speakers is with a virtual mode on the
receiver (i.e. - "Theater" or "Pop" or "Stadium" or similar fake
surround modes).

I'm curious to see what comes of this!

Matt
 
"The said:
Thanks Paul, that's fantastic. By selecting use SPDIF in powerdvd's options
(something I had overlooked) I now receive a 5.1 signal, however, I'm still
a little lost.

While the dvd being in 5.1 is dandy, I really want to use the 5.1 system for
games. However, I still cannot receive anything other than a stereo signal
(outside of powerdvd). I'm trying on both painkiller and Doom 3, both games
being 5.1 capable. You have any ideas? I'm almost certain that it should be
outputting a 5.1 signal all the time, because there's even a test utility in
the soundmax setup panel..... it rotates static noise around the speakers,
but because the decoder is still getting stereo, you don't hear the rear
speakers. There must just be a freakin' check box laying around on my PC
that'll enable the use of the SPDIF port all the time.

You've done great so far, any other ideas???

Chris
Click to expand...

It is good you've proved it can work. But, as I explained in my first
post, for a program (computer game, multimedia application etc) to
produce Dolby Digital 5.1 encoding for the SPDIF, there is a license
required. This adds to the cost of software products, so you are
unlikely to find software to do it. In addition, the encoding process
would add some delay, between the time a game made the sound, until
it actually arrived at your theatre system. I don't think you would
appreciate hearing machine gun fire, _after_ you were already dead
in your game :-)

I tried researching this earlier, and it is possible there is some
encoding software out there. What that software would do for you,
is allow, say, music source material, to be encoded in a manner suitable
for sending to the SPDIF at a later time. I haven't run into any
real time "driver", that can fool the OS into thinking it is a
virtual sound output device, and then doing encoding on the fly to
drive the SPDIF. As I said in the first paragraph, there would be
appreciable delay in such a process, so it would be suitable for
music purposes but not for games. The reason this is a workable
solution on the A7N8X-E Deluxe, is the encoding process is done
in hardware by a DSP core in the Southbridge.

HTH,
Paul
 
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