Long RCA Cable help

[BMXTRIX]

Any RG-6 cable designed to work with 'F' connectors is optimized for cable TV frequencies. It's a very poor choice for an audio interconnect cable.
* * * * * * * * * *
It could have 20dB's or more 'Common Impedance Coupling Noise' current than the coax cables I listed above.

This is just not accurate. While there are some crappy RG6 cables out there, pure copper coaxial RG6 is almost the gold standard for building quality analog audio cables because they do such a good job. Remember, we are talking about science and copper and they don't have a magic way of blocking certain frequencies in a passive piece of copper, though there are some high frequencies which have issues with capacitance, though this won't impact subs, and there can be tradeoffs between different coaxial cables in use.

To be clear, Blue Jeans Cable uses Belden 1694A cabling for their digital audio cables and makes it available to use for all analog interconnects. This is a standard high quality RG6 cable. They have a ton of science backing up their decision on this, and years in the business with a ton of whiny audiophiles who love what they have delivered, along with a ton of smart audioholics who feel the same way.

I typically use a cable more similar to the Belden 1505F for my interconnects that are short. But, at length with subwoofers, I have used quality copper coax and F connectors to a wall plate (F to RCA wallplate) or a RCA crimp connection at the ends. Just as the vast majority of the professional industry has for decades. The biggest complaint really with pure coax is the stiffness of it.

I'm not sure I would trust Monoprice cabling over BJC for a run that may take several hours or more to install. I would trust coax that I could terminate myself, but any soldered connection can have issues, and then can be tough for a person to replace.

https://www.bluejeanscable.com/store/subwoofer/index.htm

 

[ryanosaur]

To be clear, Blue Jeans Cable uses Belden 1694A cabling for their digital audio cables and makes it available to use for all analog interconnects. This is a standard high quality RG6 cable.

I have to ask for my own education, please... I am not an expert by any means.

As I understand it, the Blue Jeans cable is not RG6 rated in that it uses a 25awg conductor as shown here on their site discussing the design of their subwoofer cable.

My choice to use and recommend Monoprice was based on their use of a solid copper conductor with a defined awg attached to it (being 22awg for the standard cable, and 18awg for the two higher offerings in the subwoofer/digital coax cable category). Another one I "liked:" BlueRigger; with a copper conductor and 22awg specified (actually .64mm).
Amazon and Mediabridge, iirc, are using copper-clad steel conductors.
SVS had an interesting option for more money: though I could not get a gauge rating for their wire, they do use two individual copper conductors.
And then Blue Jeans...

Most RG59 is defined as having a shielding of 90%+, whereas, according to Sewell, RG6 originally only required 60% shielding. They continue, saying that most RG6 cable today is shielded on par with RG59. This only leaves discussion about the type of shielding: Foils, as I understand, are best suited for protecting from high frequency interference, and braids from low frequency interference.

If all are double shielded, using a good quality conductor, where does the value lie?

If I buy a $25 cable and a $150+ cable, and they both conduct the same low-voltage low frequency signal adequately from source to subwoofer, which is the best cable?

 

[Swerd]

I have to ask for my own education, please... I am not an expert by any means.

You might be over-thinking this. A little history can help you understand why there are so many different types of RG6 or RG59. Shielded coaxial cables first started being used for antenna installations for TV or FM radio. Previously, 300 ohm twin lead antenna cable was used.

Coaxial cables were especially useful for outdoor use as they performed better than aged or wet 300 ohm twin lead.

You can get coaxial cable with stranded or solid inner wires where the gauge varies from 24 to 18. This allows choices for flexibility or stiffness.

Copper coated steel inner cable is useful for long antenna runs where the cable is stretched and put under tension. This also makes the cable less flexible. Copper coated steel is fine for TV, FM, or cable TV as the carrier waves are in the megahertz range. For indoor audio use, I would use coaxial cable with stranded copper inner wire.

As far a shielding goes, more shielding makes for a thicker and less flexible cable. More shielding makes sense for long outdoor TV antenna runs. Indoors for audio, it really depends on how much electromagnetic (EMI) or radio frequency interference (RFI) you have in your home, and how flexible your cable must be. Remember that the voltage level in a sub woofer signal is much greater than the voltage levels in an antenna cable. That sub woofer signal, or any other pre-amp level signal, is less likely to suffer from EMI or RFI than a TV signal. This varies with different locations.

BMXTRIX, please correct me if I'm wrong about any of this.

 

[ryanosaur]

You might be over-thinking this.

Probably guilty as charged. but going from the level of “just pick up any old cable” to learning and understanding the why of what we are doing is important. To me, at least. When I see something not adding up, I’m going to ask for the understanding of it. And the absolute last thing I want is a cable-wars conversation!

 

[Speedskater]

This is just not accurate. While there are some crappy RG6 cables out there, pure copper coaxial RG6 is almost the gold standard for building quality analog audio cables because they do such a good job. Remember, we are talking about science and copper and they don't have a magic way of blocking certain frequencies in a passive piece of copper, though there are some high frequencies which have issues with capacitance, though this won't impact subs, and there can be tradeoffs between different coaxial cables in use.

Once again, the 75 year old generic label RG-6 doesn't tell us much. There are many different types of coax that carry the generic label RG-6. It's not a gold standard for anything.

 

[Speedskater]

Take these two Belden generic RG-6U type coax cables for example:

• 9290 has two bare copper braided shields and would be fine for an audio interconnect.
• 8228 has a Duofoil with drain wire shield and would be terrible for an audio interconnect.

 

[BMXTRIX]

Take these two Belden generic RG-6U type coax cables for example:

• 9290 has two bare copper braided shields and would be fine for an audio interconnect.
• 8228 has a Duofoil with drain wire shield and would be terrible for an audio interconnect.

In fairness, I am not able to find any specific measurements that have been taken on these cables when used with systems. Considering how often coax is used with both analog and digital systems, it would be nice to see some test results. Maybe I'm just missing something.

 

[Speedskater]

Bill Whitlock often writes on the subject and how there can be up to 26dB noise difference.

Kurt Denke has a page on the subject:
https://www.bluejeanscable.com/store/subwoofer/LC1-design-notes.htm

 

[highfigh]

I was thinking of the RG-6 cables that you find on a cable TV installers truck.
The label RG-6 only tells us the diameter, impedance and center conductor gauge. 1/4 inch, 75 Ohms & 18AWG.
Nothing about what frequency range and many other properties it was designed for.

Good cable has been tested (called sweep tested) and RG6 usually goes up to 3.5GHz, but it has no problem doing audio frequencies, too. Have you thought about the hundreds of thousands of applications where coax was used for subs that have been working for years/decades?

It is preferable to use solid copper, rather than Copper Clad Steel cable, though.

 

[highfigh]

Bill Whitlock often writes on the subject and how there can be up to 26dB noise difference.

Kurt Denke has a page on the subject:
https://www.bluejeanscable.com/store/subwoofer/LC1-design-notes.htm

Noise, at what frequencies? if it's anywhere above the HP crossover, it doesn't matter and nobody will hear it unless they know how it sounds or there's no input signal. Do you have a link to Bill's comments?

 

[Montucky]

I think we are WAY overthinking this. I've run RCA over RG-59/RG-6 many a time, and I have yet to encounter any problems except when I didn't get a good crimp on the connector (my fault). I feel as long as it's good quality cable (solid copper) and they aren't running parallel to electrical, then it's going to be just fine. Even still, I've totally repurposed existing, ancient cabling to run RCA for LFE and it's always worked like a champ. I think what makes the biggest difference is your crimping skills. Haha. BTW, I only use the Belden Snap-N-Seals these days. Awesome little ends.

RG-6's a pretty versatile cable and is an industry standard for good reason. Don't forget there's yet ANOTHER option. You can also run RCA via ethernet cable which has also come in handy for me for any number of reasons. Has that been touched on here?

 

[andyblackcat]

APORTO,

I use ebay amazon grade cables and not had any issues unless the cable of course is broken. Long leads 6 meters from my room to the kitchen which is just behind the THX home cinema.

Get your cables on ebay, amazon long meters for less money. And Ethan Winer, has already debunked all the BS snake oil cables so you should be okay with ebay, amazon grade cables without paying rip off prices.

 

[BMXTRIX]

I agree we are overthinking things as in my searchings online, this question has been asked a number of times over the years and the responses from the vast majority of professional installers is that they use coaxial cable. Often cheap stuff and sometimes better stuff, but always coax. Some terminate to RCA jacks, others use adapters. I tend to terminate to a f-connector then use a f to rca wall plate so that the customer is presented with a standard 'RCA' interface at both ends for their sub.

But, we are ALSO Audioholics and should have results based upon the science of our industry, not merely the common standard or the opinion of others. The reality of loss is quite possible, but the impact on frequencies is the ONLY reality that matters. That is, bi-wiring DOES make a difference, it can be measured. But, it is below the hearing threshold of any human being, so, while instruments can measure the difference, our ears can't, so in absolute reality, there is no advantage, under any circumstance, to bi-wire a audio setup.

So, I would love to know the answer of how different types of coaxial cable impact both analog stereo and subwoofer setups. Much less need of analog stereo interconnects these days thanks to HDMI, but subwoofer cables are still the norm, and long runs of coax are still the standard most professional installers utilize. I would like to know how CCS compares to solid copper and quad shield vs. standard, etc. Certainly, most pros aren't getting the better Belden cables, but are often getting a decent solid copper cable for their work.

 

[andyblackcat]

BMXTRIX, ^^
I think cinemas use electrical power cable for the speakers least that is how it looked behind the screen thick cable not the average, ebay, amazon grade cable for £10 for 100 meters.

Coaxial cable, yeah I can work with that never tried it for speaker cable I may give it a try I have small short run of it. I may try it for other things as well.

 

[highfigh]

I agree we are overthinking things as in my searchings online, this question has been asked a number of times over the years and the responses from the vast majority of professional installers is that they use coaxial cable. Often cheap stuff and sometimes better stuff, but always coax. Some terminate to RCA jacks, others use adapters. I tend to terminate to a f-connector then use a f to rca wall plate so that the customer is presented with a standard 'RCA' interface at both ends for their sub.

But, we are ALSO Audioholics and should have results based upon the science of our industry, not merely the common standard or the opinion of others. The reality of loss is quite possible, but the impact on frequencies is the ONLY reality that matters. That is, bi-wiring DOES make a difference, it can be measured. But, it is below the hearing threshold of any human being, so, while instruments can measure the difference, our ears can't, so in absolute reality, there is no advantage, under any circumstance, to bi-wire a audio setup.

So, I would love to know the answer of how different types of coaxial cable impact both analog stereo and subwoofer setups. Much less need of analog stereo interconnects these days thanks to HDMI, but subwoofer cables are still the norm, and long runs of coax are still the standard most professional installers utilize. I would like to know how CCS compares to solid copper and quad shield vs. standard, etc. Certainly, most pros aren't getting the better Belden cables, but are often getting a decent solid copper cable for their work.

Kurt has already covered the differences on his site WRT dual shield vs Quad. CCS can be a problem because the center conductor is much stiffer than solid Copper and in a tight bend (which should be avoided), the dielectric can be compressed due to the stiffness and that reduces the noise-rejection properties of the cable.

In the field, we buy what is available, at a price that won't make customer's eyes bug out but if you check, Belden also owns West Penn, which was a huge cable producer on its own. Coleman, Honeywell, ICE and others offer good cable, at a decent price. I don't know who makes all of them, but the only ones that are hard to terminate are the Honeywell 'bundle' (two Cat5e/two Quad Shield coax) and Munster Cable Quad shield. In the first case, it was only the white coax and in Munster's case, it was all of them, but then, it was the store owner's fault for buying the wrong ends. With the Thomas & Betts Snap N Seal ends for Quad, the Munster cable I had to re-terminate was OK. It's generally a matter of getting the right ends for the cable.

For anyone who doesn't know, the recommended bend radius for communications cable (other than speaker wire) is four times the diameter, so don't lay it over the edge of a piece of lumber, sheet metal, structural steel, etc. Also, some cables have chemicals in the jacket that can react with white PVC pipe, so make sure the cables aren't in direct contact, especially if a lot of cables are in a small area.

 

[highfigh]

BMXTRIX, ^^
I think cinemas use electrical power cable for the speakers least that is how it looked behind the screen thick cable not the average, ebay, amazon grade cable for £10 for 100 meters.

Coaxial cable, yeah I can work with that never tried it for speaker cable I may give it a try I have small short run of it. I may try it for other things as well.

Don't use coax for speakers.

 

[highfigh]

APORTO,

I use ebay amazon grade cables and not had any issues unless the cable of course is broken. Long leads 6 meters from my room to the kitchen which is just behind the THX home cinema.

Get your cables on ebay, amazon long meters for less money. And Ethan Winer, has already debunked all the BS snake oil cables so you should be okay with ebay, amazon grade cables without paying rip off prices.

This was debunked long before anyone knew Ethan Winer's name.

 

[BMXTRIX]

Kurt has already covered the differences on his site WRT dual shield vs Quad. CCS can be a problem because the center conductor is much stiffer than solid Copper and in a tight bend (which should be avoided), the dielectric can be compressed due to the stiffness and that reduces the noise-rejection properties of the cable.

Do you remember the link to that. I really remember reading about that years ago and finding the information good on that. It doesn't really cover specifically what we are talking about here, but it is much more factual than the opinion based concepts being presented here.

In the field, we buy what is available, at a price that won't make customer's eyes bug out but if you check, Belden also owns West Penn, which was a huge cable producer on its own. Coleman, Honeywell, ICE and others offer good cable, at a decent price. I don't know who makes all of them, but the only ones that are hard to terminate are the Honeywell 'bundle' (two Cat5e/two Quad Shield coax) and Munster Cable Quad shield. In the first case, it was only the white coax and in Munster's case, it was all of them, but then, it was the store owner's fault for buying the wrong ends. With the Thomas & Betts Snap N Seal ends for Quad, the Munster cable I had to re-terminate was OK. It's generally a matter of getting the right ends for the cable.

For anyone who doesn't know, the recommended bend radius for communications cable (other than speaker wire) is four times the diameter, so don't lay it over the edge of a piece of lumber, sheet metal, structural steel, etc. Also, some cables have chemicals in the jacket that can react with white PVC pipe, so make sure the cables aren't in direct contact, especially if a lot of cables are in a small area.

Yes, we buy what is available, but it really does seem like we are lacking the information in this specific area to know what difference we would have between a 50' run of different audio cables in different situations. Especially with real world measurements and some testing. I would bet, at some point, someone did this testing, but it just isn't something I've ever seen referenced or read myself. Not that there aren't differences in cables, but as we all know, lamp cord vs. speaker wire is just copper vs. copper. It tends to all work just fine if you have the right gauge for the distance. So, while speaker wire DOES have differences and is hugely open to interference due to the low voltage, how much does it matter for subs? How about for standard interconnects? I use a mini-HR cable for my audio interconnects, which seems to be near the 'ideal', for my audio distribution. My entire goal is to not hear noise added to the system when the cables are connected. Beyond that, I don't ask for much. For my good speakers and my main system, it's all HDMI. So, you know, lower standards than some have for my audio interconnects.

But, for all my subs I plan to run coax. Standard pure copper coax. I would be happy to switch up to a better coax if this is the right thing to do and would make an actual audible difference. But, I would like to know that this would be a good choice, not just an opinion.

 

[highfigh]

Do you remember the link to that. I really remember reading about that years ago and finding the information good on that. It doesn't really cover specifically what we are talking about here, but it is much more factual than the opinion based concepts being presented here.


Yes, we buy what is available, but it really does seem like we are lacking the information in this specific area to know what difference we would have between a 50' run of different audio cables in different situations. Especially with real world measurements and some testing. I would bet, at some point, someone did this testing, but it just isn't something I've ever seen referenced or read myself. Not that there aren't differences in cables, but as we all know, lamp cord vs. speaker wire is just copper vs. copper. It tends to all work just fine if you have the right gauge for the distance. So, while speaker wire DOES have differences and is hugely open to interference due to the low voltage, how much does it matter for subs? How about for standard interconnects? I use a mini-HR cable for my audio interconnects, which seems to be near the 'ideal', for my audio distribution. My entire goal is to not hear noise added to the system when the cables are connected. Beyond that, I don't ask for much. For my good speakers and my main system, it's all HDMI. So, you know, lower standards than some have for my audio interconnects.

But, for all my subs I plan to run coax. Standard pure copper coax. I would be happy to switch up to a better coax if this is the right thing to do and would make an actual audible difference. But, I would like to know that this would be a good choice, not just an opinion.

I found the article by looking around on the Blue Jeans Cable site- it wasn't long after he began posting here.

Speaker wire runs aren't affected by interference often because it's not a high impedance path and because it's after the amplifier, so the noise isn't going to get louder.That's not saying it can't be affected by something, but the only time I ever had an interference issue was on a 70V system. The voltage is a lot higher than what's on a line level cable, that's for sure.

The main problem for long subwoofer cable runs is with ground loops, not the signal quality- it's bandwidth-limited and we don't hear details well in the low end, so it's less important whether the signal is 99% perfect or 95% perfect.

How much noise/interference do you think will be added to a digital signal over HDMI, in light of the fact that an HDMI cable has four shielded conductors?

 

[APORTO]

I had a busy couple days and finally got a chance to come back to this. Wow! I got a lot of advice and some education. Thanks to all! Since so many have taken the time to provide input, I did a better job of drawing the layout. Yellow = electrical outlets; Red line = current cable; green line = desired cable run.
I currently have 4 speakers (Front L/C/R and Rear Right) already run along the green line. room is about 20ft X 20ft. I'm using Monoprice 12AWG pure copper for the speakers and do not notice any interference.
https://www.monoprice.com/product?c_id=102&cp_id=10239&cs_id=1023903&p_id=2789&seq=1&format=2

I ordered 75'
https://www.monoprice.com/product?c_id=102&cp_id=10236&cs_id=1023603&p_id=21685&seq=1&format=2
Since the wiring is thru-wall and not in-wall, if there are issues with interference, I can easily change solution and the effort + $30 price won't be a big deal.

Also, I have a curtain/faux stage the whole length of the wall with screen, so the only exposed cable that needs concealing is around the dormer. Unfortunately, 5 cables, 4 X 12AWG speaker lines and the added coaxial will be difficult to conceal. The AVR is in the back of the room because it was a short run to projector and due to unfinished attic, running the speakers wasn't difficult. The room is carpeted with extra thick padding, so a throw rug will look bad and there is too much going on in the lower right corner that I would prefer to avoid running the line unless the green-line solution doesn't work.