SonyPCH,
Can I get Vegas / SF to output a stero bus to SP/DIF, thinking of feeding Edirol monitors that way?

Yes. SP/DIF is just normal PCM i/o (to host apps) with out the A/D - D/A.

AC-3 on the other hand is not a simple multi channel streaming format.

Peter

Thanks Peter for your reply. Your input has helped me understand my problem a little better. I have no problem monitoring 5.1 out of the analog jacks of the Audigy card but I had thought the spdif outs would have the same 5.1 signal.

I will try the Direct Sound Surround mapper mode also in Vegas. I have tried many combinations in the audio prefs and have only heard stereo to my Harmon Kardon. If Vegas is not streaming AC-3, then I see why the HK receiver is only in stereo. The HK reciever is a high quality receiver with high quality speakers and therefore I wanted to use it as my main monitoring source but only have digital inputs open. I use the Audigy analog outs for small speakers just for a referance.

I suppose there is no other way around this issue, or is there? Is this something Vegas might have in the future (AC-3 streaming)? Is there another sound card or unit that can do the conversion?

I will try the settings you mentioned and thanks again for your time.

Buford

I suppose there is no other way around this issue, or is there? Is this something Vegas might have in the future (AC-3 streaming)? Is there another sound card or unit that can do the conversion?

Nope. It is unlikely that we will every stream AC-3 in real-time, because that would imply encoding in real-time. Maybe when we all get Dual hyperthreaded 10 gHz P8 CPUs.

OK.....Thanks again. I'm learning! Learning a lot!

Now that Vegas is outputing 6 channels of PCM, is there any interface that will convert to AC-3 before reaching my receiver. The Audigy Platinum EX has a AC-3 decoder (which has no effect on output from Vegas) but I guess it needs to have an AC-3 encoder in order to spit out AC-3 so that my receiver can see the signals as Dolby Digital. Right? Again, is there anything I can do, or buy to output Vegas to digitally to my receiver?

I thank you for your time.
Buford

Yes,
I'm sure Dolby make a realtime ac3 encoder.

No,
I'm sure you cannot afford it.

Another way you could get your setup to work is if you use a surround encoder program, which will encode the 5.1 channel mix into a 2 channel PCM stereo mix. You can then connect the spdif out to the H/K digital in and the H/K receiver has Dolby Prologic II and Logic 7 decoding, which will then decode the 2 channel mix back to the 5.1 surround. I'm hoping that a future version of Vegas will have realtime encoding like this, so you don't have to use other apps outside of Vegas to do this feature, but it's currently not available in Vegas. This method would be less CPU intensive as compared to AC3 streaming and you wouldn't need the Dual hyperthreaded 10 gHz P8 CPUs.

This sounds interesting but I thought Vegas has a surround encoder. I assume your suggestion if for real-time monitoring, which is what I am trying to achieve.

Can you suggest a program that will do the encoding that you mentioned in your post.

Also, I see that my Audigy card has an AC-3 decoder which could be useful in this process.

I'm a professional audio person but am learning A/V and enjoy it very much. Thanks for your suggestions and comments.

Buford

antar,
Vegas has an ac3 encoder but it isn't realtime and Vegas has no mechanism for playing out the ac3 file it creates. One of the DVD playing should be able to do that and send it down the spdif but that's not quite what you were after.

I'm a little confused and stunned, because I'm currently in the process of building a new computer with an audigy 2 platinum and was planning the same thing:

What about the on-board audio of the newer cards? I have an MSI Neo2 865PE, which has an on-board audio codec C-media 9739A. This is an alternate way to get 5.1 output without a sound card. Now I note that the sp/dif outputs are only 2-channel, so this would still require "muxing" the 6 channels into 2. Is that via ac3 only or not? IOW, can we send 6-channel PCM via the digital/optical spdif outs this way?

If possible, downside would be the increased hit on the CPU?

Pardon my ignorance. I'm searching google and can find nothing. But then I hardly know what to search for...

As far as I know the only way to get the six channels down the fibre is by converting to ac3. This is not just 'muxing'. The ac3 encoder uses a whole range of tricks to reduce the amount of bandwidth. Needless to say this is very CPU intensive. You can get more than 2 channels down a fibre link I think but not using spdif, I think you need an ADAT connection for that.

Thanks, farss, for the quick reply. Man, this thread was timely. I was just at the local Circuit City and they have a sweet deal on a $300 Sony "theater-in-box" system...but without the 6 channel input. Gargh, this new computer configuration is a real rollercoaster.

Without hijacking this thread, I started another thread in the Video forum entitled: "OT Help: 5.1 audio monitors+amp <$500?" I'm looking for a good 5.1 monitoring system as cheap as possible but up to $500. If anyone has a good idea, could they respond over there? Best suggestion, so far, has been an M-audio LX4 5.1. (I can see 5.1 systems generating some great overlap between these two forums, and its only going to get worse.)