Hello,

I am not an audio expert by any stretch of the imagination (okay, I am
probably not even considered an Audio guy), but I have a few questions
which I *hope* are not to basic to ask.

I come from a computer background and I used to teach a Computer
Networking class / course so I have some knowledge of cables and
networks (although it may be a case of a little knowledge is a
dangerous thing).

First off -- is it better to use the Fiber-Optics cable or the Coaxial
cable for hooking up Digital Audio (ie: connecting my DVD player to
the Receiver). Both the DVD player and the Receiver have connections
for both methods so I am not sure if there is any difference??

I was in an Electronics store checking out the price of different
cables and the salesman told me that the Fiber-Optics cable would give
you much better sound. Now I don't know if I am comparing apples to
apples or not, but from my computer background, because it is digital
information being sent I don't know how one method would provide
better sound over the other (as it's a digital signal). Either the
signal gets through or it doesn't? (not counting errors -- does
Digital Audio include error correction information at all?)

Secondly, what are the specs for the Coaxial cable?? Do you need to
buy a "Digital" Audio Coaxial cable?? I would assume that using a
standard "Cable" cable (RG8 -- I think) would not necessarily work,
but what about coaxial network cable.

I have a number of leftover cables from my network teaching days -- I
think that when we made the cables we use RG58 (or RG59 -- can't
remember for sure) cable. I know that it was Category 3 network cable
that we made. Is that good enough??

Also, does the connectors have to be RCA (I didn't think coaxial
cables even used RCA connectors -- I have never seen, nor heard of
their use before until now). The network cables I have use the BNC
style connectors on the ends. Could I use those or would I need (if
it can be done) to change the BNC to RCA connectors?

I don't mind buying a cable, it just seems silly to buy one when I
*could* have a whole bunch of them sitting in my basement (of course I
am also curious as well).

As I mentioned above, I don't know if I am confusing technologies or
not as I have only ever worked with Networking Cables and computers --
but I would think that they would share some of the same
characteristics / properties?

Thanks so much,

Hugh

Hugh Cowan wrote:
Hello,

I am not an audio expert by any stretch of the imagination (okay, I am
probably not even considered an Audio guy), but I have a few questions
which I *hope* are not to basic to ask.

I come from a computer background and I used to teach a Computer
Networking class / course so I have some knowledge of cables and
networks (although it may be a case of a little knowledge is a
dangerous thing).

First off -- is it better to use the Fiber-Optics cable or the Coaxial
cable for hooking up Digital Audio (ie: connecting my DVD player to
the Receiver). Both the DVD player and the Receiver have connections
for both methods so I am not sure if there is any difference??

Either would work. With optical cables, you are limited to a shorter
distance, but 6 feet or so is definitely not a problem. Most people will
not be able to tell a coax connection from an optical connection in a
blind test.


I was in an Electronics store checking out the price of different
cables and the salesman told me that the Fiber-Optics cable would give
you much better sound. Now I don't know if I am comparing apples to
apples or not, but from my computer background, because it is digital
information being sent I don't know how one method would provide
better sound over the other (as it's a digital signal). Either the
signal gets through or it doesn't? (not counting errors -- does
Digital Audio include error correction information at all?)

Yes, error correction is applied. Besides carrying the bits, the digital
connection also carries the average data clock embedded in the
transitions. It is possible to have excessive jitter in the resulting
clock if the connection distorts the waveform significantly and the DAC
fails to recover the clock cleanly, but this is very rarely a problem
with today's DAC's.

Secondly, what are the specs for the Coaxial cable?? Do you need to
buy a "Digital" Audio Coaxial cable?? I would assume that using a
standard "Cable" cable (RG8 -- I think) would not necessarily work,
but what about coaxial network cable.

75 ohm coax is recommended. Coax network cable may be 50 ohm. Regular
video cables work great.


I have a number of leftover cables from my network teaching days -- I
think that when we made the cables we use RG58 (or RG59 -- can't
remember for sure) cable. I know that it was Category 3 network cable
that we made. Is that good enough??

RG58 is 50 ohm. RG59 is 75 ohm, but you would need a RCA connector at
each end. Normally RG59 terminates in type-F connectors. You can also
buy F-to-RCA adaptors.


Also, does the connectors have to be RCA (I didn't think coaxial
cables even used RCA connectors -- I have never seen, nor heard of
their use before until now). The network cables I have use the BNC
style connectors on the ends. Could I use those or would I need (if
it can be done) to change the BNC to RCA connectors?

I don't mind buying a cable, it just seems silly to buy one when I
*could* have a whole bunch of them sitting in my basement (of course I
am also curious as well).


Use the video cables if you have them. They typically have a yellow RCA
connector at each end.

As I mentioned above, I don't know if I am confusing technologies or
not as I have only ever worked with Networking Cables and computers --
but I would think that they would share some of the same
characteristics / properties?

Network cable applications are in general much more demanding.


Thanks so much,

Hugh

Hi Hugh,

The high-end technical term for what the salesman told you is '********'
(lets see if the group moderator lets that one through) your logic
/discussion is good and as long as you are not running the coax for miles it
will do fine.

regards, Mike


"Hugh Cowan" wrote in message
news:CbJbb.547817$Ho3.95266@sccrnsc03...
Hello,

I am not an audio expert by any stretch of the imagination (okay, I am
probably not even considered an Audio guy), but I have a few questions
which I *hope* are not to basic to ask.

I come from a computer background and I used to teach a Computer
Networking class / course so I have some knowledge of cables and
networks (although it may be a case of a little knowledge is a
dangerous thing).

First off -- is it better to use the Fiber-Optics cable or the Coaxial
cable for hooking up Digital Audio (ie: connecting my DVD player to
the Receiver). Both the DVD player and the Receiver have connections
for both methods so I am not sure if there is any difference??

I was in an Electronics store checking out the price of different
cables and the salesman told me that the Fiber-Optics cable would give
you much better sound. Now I don't know if I am comparing apples to
apples or not, but from my computer background, because it is digital
information being sent I don't know how one method would provide
better sound over the other (as it's a digital signal). Either the
signal gets through or it doesn't? (not counting errors -- does
Digital Audio include error correction information at all?)

Secondly, what are the specs for the Coaxial cable?? Do you need to
buy a "Digital" Audio Coaxial cable?? I would assume that using a
standard "Cable" cable (RG8 -- I think) would not necessarily work,
but what about coaxial network cable.

I have a number of leftover cables from my network teaching days -- I
think that when we made the cables we use RG58 (or RG59 -- can't
remember for sure) cable. I know that it was Category 3 network cable
that we made. Is that good enough??

Also, does the connectors have to be RCA (I didn't think coaxial
cables even used RCA connectors -- I have never seen, nor heard of
their use before until now). The network cables I have use the BNC
style connectors on the ends. Could I use those or would I need (if
it can be done) to change the BNC to RCA connectors?

I don't mind buying a cable, it just seems silly to buy one when I
*could* have a whole bunch of them sitting in my basement (of course I
am also curious as well).

As I mentioned above, I don't know if I am confusing technologies or
not as I have only ever worked with Networking Cables and computers --
but I would think that they would share some of the same
characteristics / properties?

Thanks so much,

Hugh

On 22 Sep 2003 22:34:27 GMT, "Mike II"
wrote:

The high-end technical term for what the salesman told you is '********'
(lets see if the group moderator lets that one through) your logic
/discussion is good and as long as you are not running the coax for miles it
will do fine.

Further, the point of a properly terminated 75 ohm system is that you
*can* run it for miles without errors.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

chung wrote:

First off -- is it better to use the Fiber-Optics cable or the Coaxial
cable for hooking up Digital Audio (ie: connecting my DVD player to
the Receiver). Both the DVD player and the Receiver have connections
for both methods so I am not sure if there is any difference??

Either would work. With optical cables, you are limited to a shorter
distance, but 6 feet or so is definitely not a problem. Most people will
not be able to tell a coax connection from an optical connection in a
blind test.

The reason why optical connections are that limited in the world of
digital audio is the cheap implementation of the transmitter, receiver
and the plugs.

.. Either the
signal gets through or it doesn't? (not counting errors -- does
Digital Audio include error correction information at all?)

Yes, error correction is applied.

What kind of error correction are you writing about?

Unfortunately S/P DIF and AES/EBU is not TCP/IP.

Norbert

Hugh Cowan wrote:
chung wrote in message news:MaKbb.407910$Oz4.198852@rwcrnsc54...

Thanks for the reply and the good and useful information.


Secondly, what are the specs for the Coaxial cable?? Do you need to
buy a "Digital" Audio Coaxial cable?? I would assume that using a
standard "Cable" cable (RG8 -- I think) would not necessarily work,
but what about coaxial network cable.

75 ohm coax is recommended. Coax network cable may be 50 ohm. Regular
video cables work great.

RG58 is 50 ohm. RG59 is 75 ohm, but you would need a RCA connector at
each end. Normally RG59 terminates in type-F connectors. You can also
buy F-to-RCA adaptors.

I must have used RG59 cable because I *do* remember that we needed to
use 75 ohm terminators for the ends of the network segment / run. I
don't recall type-F connectors though. We used BNC connectors on each
end of the cable that would then connect to a "T" connector, but
that's all (we were using 10Base2 cable / networks -- ie: 10Mbps at a
maximum of 185 feet).

There are 75 ohm BNC cables available that can mate to RG-59's, so you
might have used those. If that's the case, you can get BNC-to-RCA jacks
also, but those are not cheap (a few bucks each at Radio Shack). I guess
still much cheaper than audio boutique cables.



Use the video cables if you have them. They typically have a yellow RCA
connector at each end.


Thanks for the great tip -- I am sure that I have one of those. At
least I know that I have a cable with a single RCA (yellow) connector
on each end -- I think it came with the DVD player but I'm not sure.
(I would assume that yellow is reserved for video as oppose to red &
white which is for Audio)

That would be perfect for digital audio.


Just out of curiosity -- how does the video RCA cable (yellow) differ
from the Stereo Audio cable (Red & White RCA connectors on each end).
Other than the obvious difference of two cables vs one -- I would
assume from your specific reference to *video* cable that internally
the cable is different as well?


Video cables are guaranteed to be 75 ohm coax. Audio cables are not,
although a lot of them are made the same way as video cables. Video
cables should have less loss at video frequencies (up to 10's of MHz's).
Composite video is limited to 6 MHz or so, but the HD component videos
have bandwidths in the 30 MHz range.

Thanks again for the help and information. You have saved me a few
bucks and another trip to the electronics store.

Hugh,

chung wrote:


There are 75 ohm BNC cables available that can mate to RG-59's, so you
might have used those.

Meant to say "There are 75-ohm BNC's available that can mate to RG-59's".

chung wrote in message news:MaKbb.407910$Oz4.198852@rwcrnsc54...
Hugh Cowan wrote:
I was in an Electronics store checking out the price of different
cables and the salesman told me that the Fiber-Optics cable would give
you much better sound. Now I don't know if I am comparing apples to
apples or not, but from my computer background, because it is digital
information being sent I don't know how one method would provide
better sound over the other (as it's a digital signal). Either the
signal gets through or it doesn't? (not counting errors -- does
Digital Audio include error correction information at all?)

Yes, error correction is applied.

No, it is not, not if you are using the standard AES/EBU or S/P-DIF
serial connections, or their optical equivalents. There is no error
correction available AT ALL over such connections. There is error
detection only in the sense that there is sample subframe parity
detection. All of the error correction that is applied is done when
reading off the media, before it is decoded, deinterleaved (actually,
deinterleaving is part of the error detection an correction process)
and reconstructed. At that point, all error correction is applied and
if it failed, error concealement is applied. At that point, the data is
ready to be shipped out over one of the stream protocols to the outside
world.

chung wrote in message . net...
Dick Pierce wrote:
chung wrote in message news:MaKbb.407910$Oz4.198852@rwcrnsc54...
Hugh Cowan wrote:
I was in an Electronics store checking out the price of different
cables and the salesman told me that the Fiber-Optics cable would give
you much better sound. Now I don't know if I am comparing apples to
apples or not, but from my computer background, because it is digital
information being sent I don't know how one method would provide
better sound over the other (as it's a digital signal). Either the
signal gets through or it doesn't? (not counting errors -- does
Digital Audio include error correction information at all?)

Yes, error correction is applied.

No, it is not, not if you are using the standard AES/EBU or S/P-DIF
serial connections, or their optical equivalents. There is no error
correction available AT ALL over such connections. There is error
detection only in the sense that there is sample subframe parity
detection. All of the error correction that is applied is done when
reading off the media, before it is decoded, deinterleaved (actually,
deinterleaving is part of the error detection an correction process)
and reconstructed. At that point, all error correction is applied and
if it failed, error concealement is applied. At that point, the data is
ready to be shipped out over one of the stream protocols to the outside
world.


Yes, as I said earlier, only parity detection is provided for Redbook
CD's. There is no error correction in the S/PDIF protocol.

Hold on there, you are confusing a couple of things, or at least stating
them in a confusing fashion. "Redbook CD's" have very extensive error
detection and correction, of which probably the crudest is raw parity
detection. There are, applied to ALL redbook CDs, FAR more extensive
and comprehensive error detection and correction, which is part of the
process of reading the media.

This is WHOLELY apart from transmitting the data about once it has been
read off the disk, which has NO error correction and parity -only error
detection.

Let's make sure everyone understands the difference between media reading,
demodulation and decoding, and transmission of audio stream data across
a link: they are VERY different.

In article , (Stewart
Pinkerton) writes:

Further, the point of a properly terminated 75 ohm system is that you
*can* run it for miles without errors.
--

Well, not precisely. The maximum AES3-id coax (based on a 2v source and a
200mV received signal) is 3467 ft. at 6 MHz (44.1 kHz = 5.6448 MHz) on solid
copper RG-6 coax. S/PDIF starts out with 0.5v, so it only goes a quarter of
that distance. Of course, 867 ft. is a lot longer than any house I know (even
Bill Gate's house!)

Steve Lampen
Belden Electronics Division

In article , chung
writes:

Video cables are guaranteed to be 75 ohm coax. Audio cables are not,
although a lot of them are made the same way as video cables. Video
cables should have less loss at video frequencies (up to 10's of MHz's).
Composite video is limited to 6 MHz or so, but the HD component videos
have bandwidths in the 30 MHz range.

This is an old posting, but I couldn't resist adding a comment.

The bandwidth of an analog TV signal is 6 MHz. (That's the space a channel
uses, which is why there's a new station every 6 MHz. Channel 2 = 54 MHz,
Channel 3 = 60 MHz, Channel 4 = 66 MHz .

The bandwidth for digital and HD signals is...surprise....6 MHz. After all,
they're putting HD and serial digital signals in the same channel arrangement,
so they would HAVE to be 6 MHz. (It's just a 19.4 Mbit signal in that 6 MHz
channel).

Same channels, different signals.

Steve Lampen
Belden Electronics Division

ShLampen wrote:
In article , chung
writes:

Video cables are guaranteed to be 75 ohm coax. Audio cables are not,
although a lot of them are made the same way as video cables. Video
cables should have less loss at video frequencies (up to 10's of MHz's).
Composite video is limited to 6 MHz or so, but the HD component videos
have bandwidths in the 30 MHz range.

This is an old posting, but I couldn't resist adding a comment.

The bandwidth of an analog TV signal is 6 MHz. (That's the space a channel
uses, which is why there's a new station every 6 MHz. Channel 2 = 54 MHz,
Channel 3 = 60 MHz, Channel 4 = 66 MHz .

The bandwidth for digital and HD signals is...surprise....6 MHz. After all,
they're putting HD and serial digital signals in the same channel arrangement,
so they would HAVE to be 6 MHz. (It's just a 19.4 Mbit signal in that 6 MHz
channel).

Same channels, different signals.

Steve Lampen
Belden Electronics Division

You're comparing apples vs oranges. The modulated BW of a broadcast HD
signal can be 6 MHz, but the *component video* cables carry the *analog*
Y, Pr and Pb signals which have siginificantly higher bandwidths than 6
MHz for HDTV. Those signals are analogous to the analog RGB signals that
drive a computer display terminal.