Cable for Digital Audio?

[doanster]

I've always used cheap stereo RCA cables to connect the digital coax output from my DVD player to home theatre receiver, without noticing any quality issues. I'm shopping around for a "dedicated" cable for this purpose, but I'm wondering if I'll actually notice a difference? What kind of signal degradation occurs in a lower quality cable in the context of digital audio?

 

[alfa147x]

Nothing you'll notice
also this is the correct forum:
http://forums.anandtech.com/forumdisplay.php?f=38

 

[Born2bwire]

For a digital signal it could matter. They are designed to have a specific impedance and bandwidth, all of which dictates the quality of the signal. A simple RCA is not going to be designed with these in mind (in fact, most of them have bupkiss in mind when they make them, rather intriguing to me when you consider all the snake oil that can go into it). It's not that you need to buy an ueber-mensch of a cable, anything that satisfies the specs should be good. As such, a cheapy digital coax cable from say monoprice should be more than enough for peace of mind.

 

[alfa147x]

For a digital signal it could matter. They are designed to have a specific impedance and bandwidth, all of which dictates the quality of the signal. A simple RCA is not going to be designed with these in mind (in fact, most of them have bupkiss in mind when they make them, rather intriguing to me when you consider all the snake oil that can go into it). It's not that you need to buy an ueber-mensch of a cable, anything that satisfies the specs should be good. As such, a cheapy digital coax cable from say monoprice should be more than enough for piece of mind.

Wait thought digital signals were either it works or it doesnt

 

[Born2bwire]

Wait thought digital signals were either it works or it doesnt

Correct, which is why I wouldn't recommend spending any significant amount of money on a digital cable. However, SPDIF has a problem with that it does not have proper error correction or maintainance of the timing signal. If a bit gets corrupted as it is sent, that's how it is going to be interpreted. How that affects the final sound is probably completely random. I would not prescribe that you would hear better bass or something like that, but a very intermittant error in the bitstream may raise the noise floor or, if it is a bad series of words, cause the signal to drop out momentarily. Using a cable that has improper impedance or poor bandwidth properties could exasperate any of these problems. Considering that he can get a proper coaxial cable from Monoprice for $1-$5, I say why not?

 

[alfa147x]

Correct, which is why I wouldn't recommend spending any significant amount of money on a digital cable. However, SPDIF has a problem with that it does not have proper error correction or maintainance of the timing signal. If a bit gets corrupted as it is sent, that's how it is going to be interpreted. How that affects the final sound is probably completely random. I would not prescribe that you would hear better bass or something like that, but a very intermittant error in the bitstream may raise the noise floor or, if it is a bad series of words, cause the signal to drop out momentarily. Using a cable that has improper impedance or poor bandwidth properties could exasperate any of these problems. Considering that he can get a proper coaxial cable from Monoprice for $1-$5, I say why not?

Ah I see your point!

 

[canis]

nm

 

[PurdueRy]

For a digital signal it could matter. They are designed to have a specific impedance and bandwidth, all of which dictates the quality of the signal. A simple RCA is not going to be designed with these in mind (in fact, most of them have bupkiss in mind when they make them, rather intriguing to me when you consider all the snake oil that can go into it). It's not that you need to buy an ueber-mensch of a cable, anything that satisfies the specs should be good. As such, a cheapy digital coax cable from say monoprice should be more than enough for peace of mind.

Digital coax cabling is simply 75ohm video cabling. Same exact stuff. Any decent video cable should be designed to this property.

 

[3chordcharlie]

Digital coax cabling is simply 75ohm video cabling. Same exact stuff. Any decent video cable should be designed to this property.

This part is important.

I'm not sure why, but until some of the newer equipment in the last few years, I had never actually seen a digital audio problem caused by a cable. DTS seems more affected than DD in my experience (maybe because of the higher bitrate?).

It doesn't need to be an expensive cable, but stick with one that is for video.

 

[Modelworks]

Cable length is the biggest factor. Just about anything will work if its within a couple feet. When you start going 6ft or more the longer you go the more the cable matters because of reflections. Think of it like a tunnel, the longer the tunnel when you shout in it the more the echo.

 

[Exterous]

Wait thought digital signals were either it works or it doesnt

Not really. Digital signals can suffer from degredation and with enough of that the 0 will get misinterpreted as a 1 or vise versa. As others have said length can be a big factor in this

That being said most Yellow Video cables are more than up to the task of being a Digital Coax cable

 

[doanster]

Thanks guys. Went out to the local dept store and turns out they had Monster composite video cable on sale for only $2.99 (Cdn). That's a cheap price to pay for piece of mind

 

[bobdole369]

ROFL - we are speccing 90 foot sp/dif digital coax runs with cheap ass RG-59. I'll be able to tell you how this works in about 2 months.

 

[sdifox]

ROFL - we are speccing 90 foot sp/dif digital coax runs with cheap ass RG-59. I'll be able to tell you how this works in about 2 months.

Go RG-6 if you are doing 90ft.