What's SPDIF and why should I use it?
- Thread starter K.I.L.E.R
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K.I.L.E.R said:
Don't bother using it to connect devices within a computer. It's meant to be a digital medium between discrete devices, typically in a configuration with a stereo/surround sound receiver as the recipient. Analog cabling allows interference to degrade signal quality, and the resistance of the wiring causes loss in signal power. The digital optical connection eliminates the interference and resistance so the receiver has a clean signal to process. The signal being passed between your TV tuner card and your sound card should be traveling through the computer in digital form anyway, so using the interface there is pointless.
Well, truth be told, the TV tuner card could pass the entire S/PDIF stream, which would include AC-3.
If the soundcard is dandy enough, it can take AC-3 in, and convert the stream to the analog 5.1.
Assuming, of course, that the channels you're receiving on your sound card are 5.1, and you can't get the AC-3 stream some other way.
Anyhoo...
If the soundcard is dandy enough, it can take AC-3 in, and convert the stream to the analog 5.1.
Assuming, of course, that the channels you're receiving on your sound card are 5.1, and you can't get the AC-3 stream some other way.
Anyhoo...
I always though SPDIF was to carry 5.1 surround sound from DVD player (or PC or anything else playing a DVD) to the surround sound system...? All digital and nice and sweet.
S/PDIF carries a digital bitstream.london-boy said:
PCM (2 channel)
Dolby Digital (multi-channel)
DTS (multi-channel)
RussSchultz said:
There you go... More or less what i said... Err...
What Russ said ^^
Also: SPDIF has less interferences compared to analog, be it the coax or the optic fibre version. The "real" use is thus the high-end studio stuff etc., as well as the ability to reduce cabling (which is the case with any digital interface compared to its analog counterpart anyway).
Connecting stuff which has such a lousy sound quality like a PC sound card with stuff with even worse sound quality like TV will give you no improvement over analog usually.
Also: SPDIF has less interferences compared to analog, be it the coax or the optic fibre version. The "real" use is thus the high-end studio stuff etc., as well as the ability to reduce cabling (which is the case with any digital interface compared to its analog counterpart anyway).
Connecting stuff which has such a lousy sound quality like a PC sound card with stuff with even worse sound quality like TV will give you no improvement over analog usually.
Toslink and coax digital are identical in transmission quality. A rusty nail and coat hanger rigged into a coax connection will transmit the same information as true glass fibre optic. All it sends is 0 or 1, so there aren't any tiny variations like analog cables. At higher speeds it matters, but SPDIF is extremely slow.
Because of that, it is better to use digital in PC audio, since most PC DAC's and ADC's aren't exactly great combined with the electrical noise of most PC's. Keeping the sound digital will make it perfect, as there is no interference.
Because of that, it is better to use digital in PC audio, since most PC DAC's and ADC's aren't exactly great combined with the electrical noise of most PC's. Keeping the sound digital will make it perfect, as there is no interference.
_xxx_ said:
If it fails to a point where it's error correction fails then you get either a loud pop or a total audio dropout, not slightly worse sound or anything.
For EMI to affect coax SPDIF it would have to raise the voltage by about .2-.3 volts(in order to change a 0 to a 1), which would be absurd.
Reznor007 said:
What DAC/ADCs are you talking about? The only things he has that are analog are his speakers, as far as I can tell. Maybe I'm missing something, is the capture card unable to pass the AC3 audio to the sound card over the PCI bus for some stupid reason?
What's your actual config and what exactly do you want to do with it?
EDIT:
Here's some more detailed description of the interface, maybe that will help you:
http://www.epanorama.net/documents/audio/spdif.html
EDIT:
Here's some more detailed description of the interface, maybe that will help you:
http://www.epanorama.net/documents/audio/spdif.html
Last edited by a moderator:
If you're playing with magnets, solar flares, and EMP pulses then Toslink is probably the way to go. If you like moving your cables around a lot, tying them in knots, or weaving them into nice designs then you should lean towards Coax. For most of us it doesn't matter (unless your equipment only has one type of connection). I tend to use coax because every time I get a video card it comes with a free 6' piece of 75ohm coax with RCA jacks at each end .
SPDIF should be used to get the digital audio stream to the DACs that you want to use. If your soundcard has a pro audio card with better DACs then your receiver then you will probably want to run analog cables from the card to the amp. But for most of us, our receivers will have better DACs then our soundcards, so we want to run digital links.
The data you get out is only as good as the data that is sent in. What kind of amplifier/speaker setup will factor in as well. If the show show you are watching only has a PCM stream, then analog would probably be as good as digital. On the other hand, if you're watching a HD show with an AC3 5.1 stream, you should notice a huge difference between the analog and digital, assuming you have a 5.1 speaker setup.
Note that the way your tuner card handles digital audio changes things too. Ideally a card will support a SPDIF passthrough mode, where the audio stream is just passed directly to the output connector. Some cards may cheat and decode AC3 (or DTS) streams into PCM (which is just uncompressed 2ch audio).
I thought the Theater550 was the first setup that allowed audio data to be passed over the PCI bus?
.SPDIF should be used to get the digital audio stream to the DACs that you want to use. If your soundcard has a pro audio card with better DACs then your receiver then you will probably want to run analog cables from the card to the amp. But for most of us, our receivers will have better DACs then our soundcards, so we want to run digital links.
The data you get out is only as good as the data that is sent in. What kind of amplifier/speaker setup will factor in as well. If the show show you are watching only has a PCM stream, then analog would probably be as good as digital. On the other hand, if you're watching a HD show with an AC3 5.1 stream, you should notice a huge difference between the analog and digital, assuming you have a 5.1 speaker setup.
Note that the way your tuner card handles digital audio changes things too. Ideally a card will support a SPDIF passthrough mode, where the audio stream is just passed directly to the output connector. Some cards may cheat and decode AC3 (or DTS) streams into PCM (which is just uncompressed 2ch audio).
I thought the Theater550 was the first setup that allowed audio data to be passed over the PCI bus?
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