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Is there any difference between a digital coaxial cable and a single 1 channel RCA cable ?
This thread has 28 replies. Displaying posts 16 through 29.
Post 16 made on Monday January 8, 2018 at 01:46
Mac Burks (39)
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Subwoofer would "woof" like a machine gun.

Serial digital cable as in [Link: secure.libertycable.com]
Post 17 made on Monday January 8, 2018 at 02:01
Ernie Gilman
Yes, That Ernie!
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That's odd. Can anyone think of a reason that a 4.5 GHz cable would have signal transmission problems near DC?
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
Post 18 made on Monday January 8, 2018 at 03:19
Mac Burks (39)
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On January 8, 2018 at 02:01, Ernie Gilman said...
That's odd. Can anyone think of a reason that a 4.5 GHz cable would have signal transmission problems near DC?

The serial digital cable is what was supposed to be ran. It would have worked. I use it for every coaxial signal you can think of from composite video and analaog audio to digital audio and subwoofers.

The "DirecTV" rg6 was ran by mistake. It's what wasn't working properly.
Post 19 made on Monday January 8, 2018 at 08:14
buzz
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Was the DirecTV RG-6 connected to any DirecTV hardware?
Post 20 made on Monday January 8, 2018 at 11:40
Ernie Gilman
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buzz, I think you've got it.
There is ZERO reason that any cable, be it RG6, serial digital, CAT5, even speaker wire used as line level wire, would make a subwoofer "woof" connected from the ANALOG output of an A/V receiver to a subwoofer's line input.

I think Mac's being terribly inexact in describing what happened and how he wanted the wiring to be done. If you read it again you'll see he doesn't mention just what was actually connected to what. And it really does sound like his intention was to run a digital signal to a sub.

But buzz has got it: A piece of RG6 connected to the LNB input of a satellite receiver at one end and connected to the line input of a subwoofer at the other end would, with many non-genie DirecTV receivers, "transmit" a "signal" that switches every few seconds (Mac doesn't tell us how often it "woofed") from 13 VDC to 18 VDC. Older satellite receivers did this to try to get an LNB to respond. I believe that some newer models that are SWM-only don't send out DC.

Line level signals are in the range of a volt. Can you imagine the subwoofer NOT going nuts if fed a voltage that switches from 13 to 18 volts DC?
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
Post 21 made on Monday January 8, 2018 at 12:24
Mac Burks (39)
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I dont know how else to explain it. We had RG6 meant for a DirecTV satellite dish installation at the job site. Black coaxial cable rolled around a spool. We also had a spool of black "mini rg-59" aka 23 gauge Serial Digital cable rolled around a spool sitting next to it.

To be clear. I did not roll the wire around the spool. The painter didn't do it. The cable manufacturer did it. Just wanted to make sure that you didn't start investigating the possibility of wire being too tightly wound around a spool or whether or not the spool was actually a space heater etc. Basically we had two rolls of wire sitting on a floor at a construction site.

The electrician incorrectly grabbed the RG6 when he pulled the wire between the AVR cabinet and the subwoofer location.

For some reason unkown to me...the subwoofer even when the AVR was off...would "woof" like it was receiving a signal.

And NO...there were no DirecTV receivers connected between the AVR and the subwoofer unless someone (was it you, Ernie?) brought one in before drywall and installed it into the wall cavities and some how powered it with an outlet that no one could find to drive me crazy.

Using analog audio over Cat5 baluns solved the problem. The problem being we needed the subwoofer to operate normally.

No one has ever investigated the RG6. The labor hours to troubleshoot cost more than a pair of baluns.


Adding...
Before this we had never used RG6 for a subwoofer location.
After this we have never used RG6 for a subwoofer.
The only reason RG6 was used for the subwoofer here is because it was pulled by mistake.

I dont know if RG6 works just fine for subs. I dont know if it always causes a problem. I dont know because i have never had a reason to use RG6 for a sub so i have no experience with how it behaves.

This is what we pull between AVR's and Subwoofers. Serial Digital gets used 99.99999999% of the time.

Serial Digital mini rg59
Cat5
14/4
Post 22 made on Monday January 8, 2018 at 14:05
Ernie Gilman
Yes, That Ernie!
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On January 8, 2018 at 12:24, Mac Burks (39) said...
I dont know how else to explain it.

By thinking "if some incredible audio/video guru who charges $300 per hour were to offer to help me here, what details would I include in my description of the problem?" I'm definitely not saying I'm he, I'm just saying that's the kind of mindset that results in questions that don't need clarification.

I dont know if RG6 works just fine for subs. I dont know if it always causes a problem. I dont know because i have never had a reason to use RG6 for a sub so i have no experience with how it behaves.

RG6 can be used for audio. Its only drawback is its lack of flexibility, and I'm sure some would argue that CCS would not perform as well. That's a long argument.

I've said over and over that we should all understand as much as we can about the stuff we use, even if it's just so we can know whether we have to rebuild a section of the house if we need to get audio from one place to another and only the wrong wire is in place.

This is what we pull between AVR's and Subwoofers. Serial Digital gets used 99.99999999% of the time.

You realize that implies that you've done ten billion installs and you didn't use this cable in only one of them, right?


Humor.
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
Post 23 made on Monday January 8, 2018 at 14:32
Mac Burks (39)
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On January 8, 2018 at 14:05, Ernie Gilman said...
By thinking "if some incredible audio/video guru who charges $300 per hour were to offer to help me here, what details would I include in my description of the problem?" I'm definitely not saying I'm he, I'm just saying that's the kind of mindset that results in questions that don't need clarification.

I didnt ask for help. I mentioned an issue i had with RG6 and a subwoofer.

RG6 can be used for audio. Its only drawback is its lack of flexibility, and I'm sure some would argue that CCS would not perform as well. That's a long argument.

I will take your word for it. I have no interest in using RG6 for audio.

I've said over and over that we should all understand as much as we can about the stuff we use, even if it's just so we can know whether we have to rebuild a section of the house if we need to get audio from one place to another and only the wrong wire is in place.

You realize that implies that you've done ten billion installs and you didn't use this cable in only one of them, right?

Yes. I count my installs like the president counts his money. I feel like its ten billion.

Humor.
Post 24 made on Monday January 8, 2018 at 14:58
buzz
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On January 8, 2018 at 14:05, Ernie Gilman said...
RG6 can be used for audio. Its only drawback is its lack of flexibility, and I'm sure some would argue that CCS would not perform as well. That's a long argument.

For me, lack of flexibility is a major disadvantage, mainly due to the solid center conductor. I'm also not fond of the (typically) aluminum shields. I'll use stranded RG59 with a copper braid shield, then terminate with soldered RCA plugs. Otherwise the most practical termination is an F-connector and F-connector to RCA adapter, but this is too much of a Rube Goldberg arrangement.
Post 25 made on Tuesday January 9, 2018 at 09:15
Ernie Gilman
Yes, That Ernie!
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On January 8, 2018 at 14:58, buzz said...
For me, lack of flexibility is a major disadvantage, mainly due to the solid center conductor.

I didn't mean to imply that flexibility is a small problem, just that it's about the only problem. I'm also not recommending RG6 for this use, but instead pointing out that it COULD be used for this. While I'm highly in favor of using just the right product, I also recognize that sometimes things are run that we have to use, and it's good to understand ahead of time whether there will be a performance problem, and just what that problem might be, when not using one's first choice.

I'm also not fond of the (typically) aluminum shields. I'll use stranded RG59 with a copper braid shield, then terminate with soldered RCA plugs.

Yes.
Otherwise the most practical termination is an F-connector and F-connector to RCA adapter, but this is too much of a Rube Goldberg arrangement.

This is the combination that introduced me to the odd world of using RG6 for video. The introduction was "here, meet some wiring that has failed. The installer used a wire he couldn't solder to, which required an additional point of possible failure (the connection between the center conductor and the adaptor) at each end of the cable."
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
Post 26 made on Tuesday January 9, 2018 at 16:57
crosen
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On January 8, 2018 at 14:58, buzz said...
For me, lack of flexibility is a major disadvantage, mainly due to the solid center conductor. I'm also not fond of the (typically) aluminum shields. I'll use stranded RG59 with a copper braid shield, then terminate with soldered RCA plugs. Otherwise the most practical termination is an F-connector and F-connector to RCA adapter, but this is too much of a Rube Goldberg arrangement.

Why not put compression RCA ends directly on the RG59? Is this a problem with a solid center conductor?
If it's not simple, it's not sufficiently advanced.
Post 27 made on Tuesday January 9, 2018 at 20:18
Ranger Home
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We've run RG6QS for every sub install we've ever done. Theres something better? have never EVER had a subwoofer issue due to using RG6. Its in wall, terminated with an RCA keystone) both ends, then a cable from inwall jack to avr/sub. Whats wrong with that?
Post 28 made on Tuesday January 9, 2018 at 20:50
Ernie Gilman
Yes, That Ernie!
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Ranger,
there's absolutely nothing wrong with RG6 for a sub. Since RG6 was developed for the purpose of getting video and antenna signals from one place to another, and the quad shield's purpose is to make double double sure that the cable doesn't pick up RF interference, it's just not what you'd expect someone to choose for an audio wire. The fact that the common connector for it is an F connector makes it not the best choice for audio. But that's for reasons of how you use it and what limits it places on you. It's not because the cable can't properly transfer the signal.

We've had a discussion here in the past as to whether it's okay to use RG6 for audio. That was started by someone who had only used cable designed for audio. It's a good question because it's good to know the capabilities and limits of the things we use. That way, if we have some strangely limited circumstance, we'll be able to think our way out of what looks like a problem.

I've told here about an excellent cable installer who was trained to NEVER use an F81. He was told that an F81 lowers an RF signal by something like 3 dB. So, sure, he always ran a new cable if what he had was too short. But I explained what 3dB meant in terms of power, and then I stacked up six F81s and showed him with a signal meter that the total loss was only a bit more than one dB.

See, he had not been taught to know all about and understand what he was doing. He had been taught in a way that made him afraid to do anything that varied from the instructions he was given.

Life isn't like that. We often have to use things not designed for the purposes at hand.
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
Post 29 made on Wednesday January 10, 2018 at 11:32
buzz
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On January 9, 2018 at 16:57, crosen said...
Why not put compression RCA ends directly on the RG59? Is this a problem with a solid center conductor?

In terms of conductivity, this is not much of an issue and I have compression RCA’s on hand to cover this situation, but I’m still a little queasy about flexibility. At the risk of adding more conductivity and reliability issues, I might add a short section of flexible audio cable at one or both ends if there is a risk that someone might move something.
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