[truthseeker]

I've read some conflicting information on this topic and was looking for some clarity on using RG6 coax cable for audio interconnects.


I have about a 25 ft. run from my htpc to my A/V receiver, can I use an RG6 coax (Belden 9116) cable with RCA connectors as a digital audio cable without doing any damage to the components?


Has anybody had success doing this?


Any guidance is greatly appreciated...

 

[Toxarch]

I haven't done it for anything more than 5-6 feet but as far as I know you definitely can without problems. I use RG6 cables for digital audio and component cables.

 

[audiblesolutions]

Any time you are sending demodulated signals it is best to use pure copper cables. Many RG-6 coaxial cables are made to carry RF signals and their copper center conductor is coated with steel to make it stronger. This does not effect its performance as it is carrying RF signals but when you are carrying voltages it will effect performance. Beldon 9116 was intended to be used in CATV systems carrying RF signals not for video. However, it will carry the signal 25 ft. In general, though your ability to drive a digital signal any length is a function of the driver circuitry in the digital output. If you want to be certain take a 25 ft length of cable, move the receiver close to the HTPC and connect the system. If there are no problems reinstall the equipment its original positions and run the cable.


Alan

 

[ProofTech]

I’m using 50’ of Radio Shack quad-shield to connect my PC to my A/V receiver and it sounds great to my ears.

 

[Toxarch]

I think you are mistaken about the center wire in coax cables. Some wires are coated in copper. I've never seen a copper wire coated in steel in a coax wire.


BTW, I also use RG6-Quad. It's just a better shielding.

 

[audiblesolutions]

Example: Beldon 9116. Example of pure copper Coax: Beldon 8281. If you are going to run audio on coax this is the way to do it.


Alan

 

[NightHawk]

audiblesolutions;

Your tutorial on cable is full of holes. You need to do some more research before waxing prophetically.

 

[M NEWMAN]

I have run digital coax signals down 3 ft of coat hanger wire to demonstrate the durability of this signal format. You will have no problems at 25 ft with ANY RG-6 or RG-59, regardless of the quality of either cable. There isn't a coax currently made poorly enough to block that signal, or introduce enough noise to affect the digital bitstream suffiently to affect it. Obviously, however, the better quality cables will insure the most flawless and noise free transmission (for long distances), although any noise is rejected due to the bitstream containing the info needed and the noise being irrelevant (unless it's strong enough to interfere).

 

[tsteves]

I'm sure audiblesolutions meant that copper coated steel is used on some cheap rg6. It is used alot by cable companies around here. I would not use it for anything but rf.

 

[audiblesolutions]

Nighthawk

I am not always correct but you would do well to open a Beldon spec book before opening your mouth ( metaphorically speaking ). Look at the Beldon catalog, http://bwccat.belden.com/ecat/jsp/In...5=null&P6=null

Under Search type in 9116................


and what do you find: " solid conductor material: BCCS - bare copper covered steel.... " The wire was designed and manufactured for RF not for audio signals. But hey no one ever said you could not use speaker wire for voice, or 5 conductor cabled wire for microphone or Romex or 23 conductor x 30 for speakers.


And because something works does not mean there are not consequences such as added jitter and other timing problems, impedance mismatches and other assorted nasties from using incorrect cables.


This is not theory or speculation; it is not opinion or witchcraft, or any other audiophile nonsense you may wish to sprout. It comes right out of the manufacturer's's catalog and understanding it is EE101. It might prove useful to actually look at the manufacturer's specifications before sounding off.


Alan

 

[JohnFR]

I'm using a 22' length of plain old Radio Shack RG59 to run digital from my PC to my receiver to play MP3 music. Been using it for over a year and never had a drop. It's more flexible and easier to work with than RG6. Don't really see a reason to use to the heavier cable for this application. For me the proof is in the pudding, but more exotic cable, as usual, never hurts and only costs more.

 

[NightHawk]

audiblesoultions;

The cable you refer to is copper coated steel, not a copper center covered with steel as you stated. It's manfactured that way for tensile strength and nothing else. Although there is generally no requirement for tensile strength in an home audio interconnect, the only downside to using CCS cable is a miniscule increase in the DC resistance. In a 25 foot run the difference in DC (or audio) resistance is less than a quarter Ohm. Otherwise it will work just as well as pure copper for audio. The original poster was asking about digital audio and in that case the CCS cable would be even more appropriate due to the higher frequency components of the digitally modulated signal. Belden specialty RG6 cables have differences intended for different uses but those differences usually become important over miles of cable, not 25 feet.


The fact that a signal is demodulated or not has little bearing on the issue. If you were refering to the frequency translation, say so.


Your statement on voltages made no sense. RF signals have a voltage component just the same as audio does.


I have never 'Sprout' audiophile non-sense.

 

[EricB]

I use RG-6 for my digital audio connection, and I likewise use RG-6 to connect my sub to the sub out of my receiver. Its a robust performer, I must say.

 

[tsteves]

I use belden 1694a rg6 coax with canare rca's for digital audio and subwoofer. I like it, but am starting to experiment with some belden 89259 for coax and subwoofer. I probably spend too much time at audioasylum. It just seems like rg6 with 18awg center conductor may have too much skin effect. It seems like the 89259 may give a wider soundstage as a digital interconnect. I still have to experiment a bit more. I realize it seems like a doubtful proposition that skin effect or dialectric would cause sound differences with coax digital cables. Maybe my receiver is susceptible to jitter.

 

[Swampfox]

Quote:

Originally posted by tsteves It just seems like rg6 with 18awg center conductor may have too much skin effect. It seems like the 89259 may give a wider soundstage as a digital interconnect. I still have to experiment a bit more.

Frequency determines skin effect, not center conductor size. Since SPDIF is only 2 MHz, the advantage of RG6 over RG59 is nominal at best, but to say that RG59 is better than RG6 because of skin effect is ill informed. Generally, when skin effects dominate, larger conductor size is beneficial.

 

[Bill Lummus]

SPDIF has a maximum bandwidth of just under 6mhz with harmonics extending well above that level.


A little more detail? sure...


sampling rate 44.1 khz

32 bits (or cells) per sample

2 channels


1/(44100x32x2) = 354 ns/cell


"1" bits have transitions at the beginning and midpoint of the cell, thus the maximum rate of transitions is 1/177e-9 which equals 5.6 mhz.

 

[M NEWMAN]

Quote:

Originally posted by tsteves I use belden 1694a rg6 coax with canare rca's for digital audio and subwoofer. I like it, but am starting to experiment with some belden 89259 for coax and subwoofer. I probably spend too much time at audioasylum. It just seems like rg6 with 18awg center conductor may have too much skin effect. It seems like the 89259 may give a wider soundstage as a digital interconnect. I still have to experiment a bit more. I realize it seems like a doubtful proposition that skin effect or dialectric would cause sound differences with coax digital cables. Maybe my receiver is susceptible to jitter.

While your efforts to improve your audio system's performance are admirable, experimenting with different types of RG-6 to achieve it are going to be a fairly useless endeavor. Skin effect won't become a significant issue unless you are either:

A) sending your signal down several hundred feet of wire, in which case DC resistance will be a far more serious issue than high frequency impedance problems.

B) you're running signals down the wire that are into the 2 gigahertz and higher range. I doubt you qualify for either predicament, hence, the quest for a better performing RG-6 won't reveal anything different.


Also, coaxial digital isn't subject to the same problems with jitter that optical is. I doubt very much that your reciever is having the "jitters". The quality of the digital circuitry inside, or the decoder, however, could certainly be an issue. Your best bet to significantly improve your soundstage is room treatment and careful speaker placement IMHO.

 

[tsteves]

Swampfox

"Generally, when skin effects dominate, larger conductor size is beneficial."

Possibly I am misinformed, but this is the exact opposite of what I understand to be true. I think there should be less proportional skin effect with smaller diameter wire at a given frequency. I'm not talking of wires where skin effect predominates - I would think that should be avoided.

I really don't think it's about that anyway.

Maybe it's dialectric transient distortion. Teflon is better, etc. Maybe it's my imagination.

Jeez, I am experimenting, listening and expressing some "maybes". Stone me when I actually make a definitive statement.

 

[tsteves]

M NEWMAN

Thanks for your thoughtful post.

Hey basically I'm agreeing that RG6 is great for a digital audio cable. I just like to try things out. 89259 is an RG59 with a 22 awg center conductor. Worse for long runs than RG6. Very good materials. I tried a few cable swaps and thought I might have heard a difference. I am probably wrong. Hard to set up an A/B test rig. I doubt numbers are the end all. Not enough numbers involved. I enjoy listening and deciding for myself.

 

[Swampfox]

Quote:

Originally posted by Bill Lummus SPDIF has a maximum bandwidth of just under 6mhz with harmonics extending well above that level. A little more detail? sure... sampling rate 44.1 khz 32 bits (or cells) per sample 2 channels 1/(44100x32x2) = 354 ns/cell "1" bits have transitions at the beginning and midpoint of the cell, thus the maximum rate of transitions is 1/177e-9 which equals 5.6 mhz.

Harmonics are unimportant for digital transmission.

Standard S/PDIF is one 16 bit word per channel, not two. Thus, the standard for 16 bit transfers requires a 2.8 M bit stream. 48Khz data streams are 3.0 Mbit. Sorry for the error, but is really doesn't change anything.