Optical S/PDIF vs Coaxial S/PDIF

[mb]

My new computer has outputs for both of these, and my speakers have inputs for both. Right now I have an optical spdif cable and the sound is good, but it's really short and I'm going to buy a longer cable. Should I stick with opical or switch to coaxial?

Thanks!

 

[CraigRT]

I always read, for home theater at least, they were very similar.
although some people claimed coaxial had the slight edge overall.. I use coaxial.

 

[mb]

I just found this page that pretty much says that. I guess I'll go with what I can find for a good price.

Thanks for your input CraigRT.

If anyone has anything else to say I'd like to hear it, especially if it's with an ASUS mobo and/or Logitech Z680s.

 

[CraigRT]

No problem.. just remember, either of which you go for, will sound probably 100% fine!
the only other problem with optical is that you can't let the cable get damaged at all, (bent or have something crush it a little) but with a coaxial you don't really have to worry about it. keep that in mind also.

 

[beatle]

You won't notice a difference in quality. I use either, depending on what the device is capable of. If it has both, I use optical just because the cables are cheap and I have extras.

 

[mb]

I found one of these in my extra box of cables.. think it will work? I'd test it but all my stuff is packed up until Thursday.

 

[Ryoga]

Coax is subject to EM interference. Optical is not. Optical cables are more expensive, more prone to damage, and can't be cut to length without some pretty specific equipment (not that doing the same to RCA is easy).

 

[minofifa]

one other thing you have to watch out for with optical (and possibly with coaxial too but i don't know for sure) is the length. After a few meters, there is something like a 3 db loss in quality for every meter added. at least that is what one of my manuals says.

 

[CSMR]

You may get a loss in quality owing to increased jitter - this depends on the dac receiving the signal -, but I don't know what is meant by a 3db loss in quality.

 

[batmanuel]

According to a friend of mine who keep up with home theater tech, coax is a bit better for music and DD, while DTS sounds better via optical. For a while, I had my DVD player hooked up to my home theater with both coax and optical, and I could discern a bit of a difference between the two when I toggled between the two inputs. It may just be my equipment, but I thought that the sound seemed a bit fuller with the coax. Of course, being digital you'd figure that both would sound exactly the same.

 

[oneshot47]

Even the hard core audiophiles with $100000 systems have to debate on which one is better. Don't stress out on it too much. I guarantee there will be no real discernable difference, though you might think there is.

 

[Pariah]

According to a friend of mine who keep up with home theater tech, coax is a bit better for music and DD, while DTS sounds better via optical.

That doesn't really make any sense, since neither DD or DTS are music so to speak. They're only digitally encoded data that needs to be decoded by the appropriate decoder after it's already been transferred. Saying the transport is better for either format, while not for the other is like saying USB is better and more reliable for transferring data that is zipped, while firewire is better for data that is rar'd. Both are digital, either you get the file, or you don't, and 99.999% of the time, the data that is received is identical to the data that was sent.

Unless you have "golden ears," or there is something wrong with how the connections were made, you will not hear a difference between the 2, since technically they are doing the exact same thing, digitally transferring data.

 

[Goosemaster]

Originally posted by: Pariah

According to a friend of mine who keep up with home theater tech, coax is a bit better for music and DD, while DTS sounds better via optical.

That doesn't really make any sense

 

[CSMR]

Originally posted by: Pariah
That doesn't really make any sense, since neither DD or DTS are music so to speak. They're only digitally encoded data that needs to be decoded by the appropriate decoder after it's already been transferred. Saying the transport is better for either format, while not for the other is like saying USB is better and more reliable for transferring data that is zipped, while firewire is better for data that is rar'd. Both are digital, either you get the file, or you don't, and 99.999% of the time, the data that is received is identical to the data that was sent.

The trouble is (apparently) DACs are not essentially digital. Computers work in a digital way - 1s and 0s are processed into other 1s and 0s. These 1s and 0s are in fact imperfect analog signals which have voltages that are approximately 1s and 0s and which don't switch instantly, but imperfections in input don't have an effect in imperfections in output - that's the way computer circuits are. For this reason no-one asks how good a USB port is - if it works it works. (If we had 0.9 AND 0.9 evaluated as 0.8, say, and so on, a computer would fail almost instantly; instead it is evaluated as - about 1.)
Simple DACs on the other hand effect - I believe - an analog transformation of the input. Now the input is "digital" but has to be considered as an analog signal - a jagged rather than smooth wave. Slight hanges in this signal have an effect on the output, unlike in computers.
Sore advanced DACs take the incoming data and treat it as digital, reclocking it and converting it to a better digital signal before converting it to analog in an analog way - here the quality of input will be irrelevant.
I am not an engineer or audio expert, so please correct me if I'm wrong.
As for whether optical or digital is better, in the past coaxial was considered superior, but optical equipment has improved apparently; there are advocates for both, but the difference isn't considered important.

 

[oneshot47]

Originally posted by: CSMR

Originally posted by: Pariah
That doesn't really make any sense, since neither DD or DTS are music so to speak. They're only digitally encoded data that needs to be decoded by the appropriate decoder after it's already been transferred. Saying the transport is better for either format, while not for the other is like saying USB is better and more reliable for transferring data that is zipped, while firewire is better for data that is rar'd. Both are digital, either you get the file, or you don't, and 99.999% of the time, the data that is received is identical to the data that was sent.

The trouble is (apparently) DACs are not essentially digital. Computers work in a digital way - 1s and 0s are processed into other 1s and 0s. These 1s and 0s are in fact imperfect analog signals which have voltages that are approximately 1s and 0s and which don't switch instantly, but imperfections in input don't have an effect in imperfections in output - that's the way computer circuits are. For this reason no-one asks how good a USB port is - if it works it works. (If we had 0.9 AND 0.9 evaluated as 0.8, say, and so on, a computer would fail almost instantly; instead it is evaluated as - about 1.)
Simple DACs on the other hand effect - I believe - an analog transformation of the input. Now the input is "digital" but has to be considered as an analog signal - a jagged rather than smooth wave. Slight hanges in this signal have an effect on the output, unlike in computers.
Sore advanced DACs take the incoming data and treat it as digital, reclocking it and converting it to a better digital signal before converting it to analog in an analog way - here the quality of input will be irrelevant.
I am not an engineer or audio expert, so please correct me if I'm wrong.
As for whether optical or digital is better, in the past coaxial was considered superior, but optical equipment has improved apparently; there are advocates for both, but the difference isn't considered important.

Well, as a matter of fact DACs are "essentially digital'. In fact they can decode straight pcm (wave) streams just like your computer. All they do is sample the stream of bits coming from the source and convert a digitally represented waveform into an analog audio signal. Fancy cables are not required either, you can use any rca cable to do coax and it will sound fine. The reason people buy the big expensive cables (besides bragging rights for their so called "golden ears") is for better shielding against interference that can introduce errors into the stream. This is analogous to the 80 wire ide cables that are required for ata 133, they eliminate interference better than 40 wire cables. Optical cables obviously dont have this problem. However, I believe that coax cables can run faster sample rates than optical. In any case, no human can really tell a difference between one and the other. I use coax because the cables are cheaper (just a cheap long rca cable is good for me), and i am actually feeding a large expensive stereo system with it.

 

[Pariah]

At what point from the original reading from the disc to the final destination of the decoder, would a DTS or DD stream hit a DAC/ADC or anything else that would alter its original digital data?

 

[oneshot47]

Originally posted by: Pariah
At what point from the original reading from the disc to the final destination of the decoder, would a DTS or DD stream hit a DAC/ADC or anything else that would alter its original digital data?

They dont.....im not sure who this is directed at though.

 

[Pariah]

Originally posted by: oneshot47

Originally posted by: Pariah
At what point from the original reading from the disc to the final destination of the decoder, would a DTS or DD stream hit a DAC/ADC or anything else that would alter its original digital data?

They dont.....im not sure who this is directed at though.

Exactly, they don't. Which was my response to CSMR, who for some reason responded to my post, talking about DAC's and ADC's which were not relevant to my original post saying neither optical or coax are better or worse than the other for transferring DD or DTS streams which batmanuel claimed above.

 

[mb]

Originally posted by: supafly
I found one of these in my extra box of cables.. think it will work? I'd test it but all my stuff is packed up until Thursday.

Bueller? Bueller?

 

[oneshot47]

Originally posted by: supafly
I found one of these in my extra box of cables.. think it will work? I'd test it but all my stuff is packed up until Thursday.

Its fine. Any rca cable will be fine.

 

[CSMR]

Originally posted by: oneshot47
Well, as a matter of fact DACs are "essentially digital'. In fact they can decode straight pcm (wave) streams just like your computer. All they do is sample the stream of bits coming from the source and convert a digitally represented waveform into an analog audio signal. Fancy cables are not required either, you can use any rca cable to do coax and it will sound fine. The reason people buy the big expensive cables (besides bragging rights for their so called "golden ears") is for better shielding against interference that can introduce errors into the stream. This is analogous to the 80 wire ide cables that are required for ata 133, they eliminate interference better than 40 wire cables. Optical cables obviously dont have this problem. In any case, no human can really tell a difference between one and the other. I use coax because the cables are cheaper (just a cheap long rca cable is good for me), and i am actually feeding a large expensive stereo system with it.

It's unlikely that it's actual errors that cause bad dac-output: errors would appear as pops in the sound, just as if you took a wav file, altered one bit randomly and played it - there would be a pop. However when people talk about the quality of digital output and even digital cables they aren't referring to pops but to something considerably subtler! Many people in fact claim quite confidently that the quality of digital output makes a difference, and say what it is. If you're a skeptic I'm sure that blind tests must have been performed, which I'll look for if you really want.
(If the input can do non-pcm decoding, then it must pass through a computer-like process and so the quality of input doesn't matter (as long as it's not so inaccurate as to cause errors). DACs generally don't decode anything.)

 

[mb]

Originally posted by: oneshot47

Originally posted by: supafly
I found one of these in my extra box of cables.. think it will work? I'd test it but all my stuff is packed up until Thursday.

Its fine. Any rca cable will be fine.

Cool, thanks.

 

[oneshot47]

Originally posted by: CSMR

Originally posted by: oneshot47
Well, as a matter of fact DACs are "essentially digital'. In fact they can decode straight pcm (wave) streams just like your computer. All they do is sample the stream of bits coming from the source and convert a digitally represented waveform into an analog audio signal. Fancy cables are not required either, you can use any rca cable to do coax and it will sound fine. The reason people buy the big expensive cables (besides bragging rights for their so called "golden ears") is for better shielding against interference that can introduce errors into the stream. This is analogous to the 80 wire ide cables that are required for ata 133, they eliminate interference better than 40 wire cables. Optical cables obviously dont have this problem. In any case, no human can really tell a difference between one and the other. I use coax because the cables are cheaper (just a cheap long rca cable is good for me), and i am actually feeding a large expensive stereo system with it.

It's unlikely that it's actual errors that cause bad dac-output: errors would appear as pops in the sound, just as if you took a wav file, altered one bit randomly and played it - there would be a pop. However when people talk about the quality of digital output and even digital cables they aren't referring to pops but to something considerably subtler! Many people in fact claim quite confidently that the quality of digital output makes a difference, and say what it is. If you're a skeptic I'm sure that blind tests must have been performed, which I'll look for if you really want.
(If the input can do non-pcm decoding, then it must pass through a computer-like process and so the quality of input doesn't matter (as long as it's not so inaccurate as to cause errors). DACs generally don't decode anything.)

Im not really sure what the point youre trying to make is For one, if you randomly flip one bit in a wave file, you wont here it. One sample in 44.1 thousand per second will be altered, you cant hear that. My point is that which cable you use doesnt really matter. Sure, theoretically one may be better than the other or whatever, but no speaker on earth can make those kinds of distinctions, and certainly not that anyone would be able to tell.

(have you and i discussed this kind of thing on here before CSMR?)

 

[CSMR]

Originally posted by: Pariah
At what point from the original reading from the disc to the final destination of the decoder, would a DTS or DD stream hit a DAC/ADC or anything else that would alter its original digital data?

Exactly, they don't. Which was my response to CSMR, who for some reason responded to my post, talking about DAC's and ADC's which were not relevant to my original post saying neither optical or coax are better or worse than the other for transferring DD or DTS streams which batmanuel claimed above.

Sorry; you are right. I wasn't attentive and didn't realise you were talking about DD and DTS only. I don't know what they are, but presumably they are some encoding scheme and the DAC would come in the next step in the chain, and the digital input quality, which is to the decoder not the DAC, would not matter. I was talking about normal digital transmission (unencoded PCM) direct to a DAC.

 

[CSMR]

Originally posted by: oneshot47
Im not really sure what the point youre trying to make is For one, if you randomly flip one bit in a wave file, you wont here it. One sample in 44.1 thousand per second will be altered, you cant hear that. My point is that which cable you use doesnt really matter. Sure, theoretically one may be better than the other or whatever, but no speaker on earth can make those kinds of distinctions, and certainly not that anyone would be able to tell.
(have you and i discussed this kind of thing on here before CSMR?)

I think you will hear it: those are the errors you sometimes get if you rip CDs with software that doesn't check well for errors. Isolated errors appear as clicks. Know a way to flip a bit randomly? I don't know how to do this in Windows.
No, we haven't I don't think.