onboard spdif

[x_taxi]

has anyone had any experience usin the onboard spdif on the motherboard?  like those found on the msi models?  does it really output 6 channels as it specifies on the website?  short of just buyin it just to test it out, hope you guys have the answers.

i'm just thinkin if it'd be a good option for a midi slave computer.  i'll just patch it up to the digital in of my interface, which is sadly only a stereo spdif.  if not, guess i'll have to revive my old audigy.

thanks masters!

 

[abusound]

Hi X-Taxi,

The way I understand SPDIF is that it's primarily designed to carry 4 channels of audio over a single port. Now for SPDIF to carry 6 channels, audio must be compressed to fit the bandwidth of the SPDIF channel. To do this compression, you will need an encoder that would compress the audio into a format like the Dolby AC-3. Now you will not have an issue decoding this since most digital interfaces can decode AC-3. So for your question regarding the MSI mobo, yes, it might be able to output 6 channels via SPDIF.

Abusound

[KitC]

S/pdif is normally a 2-channel/stereo protocol. The '6-channel' version actually is an AC-3/AC97 encoded version that does carry surround information. The problem with most onboard s/pdif is their fixed samplerate, 48 khz. There is no way to change this.

[KitC]

Latency with s/pdif? I've never known any but I've never had the chance to throw a signal roundtrip yet. My guess is it depends on the 'receiving' device.

[KitC]

Let's put it this way. Any digital device will have some form of latency regardless of the kind of device... it's just the nature of the beast at this point in time. S/pdif is just a means of delivering audio to and from a couple of digital devices, the only thing it lacks are A/D/A conversions so it should be about 2 ms faster compared to audio going through converters (the conversion process adds about 1 ms through A/D and 1 ms through D/A).

This means that the latency you will incur is very much dependent on the external device you are sending your s/pdif signal to. Remember that latency is both input and output, so if your interface reports a latency of say 5 ms, your total system latency is probably in the 11 ms range. Since the device is outside of your DAW environment, it is not covered by any PDC (plugin delay compensation); bouncing will be affected by this delay.

There is a workaround. Send an impulse like a click through the system and record the s/pdif input. Compare the time difference between the original click and the recorded click (set up 2 tracks in your DAW for that). You should be able to manually add the time shift to each uneffected track so that it lines up with the fx track on playback. Or.... you can always line up the effected track manually.