Blue Jeans Cable recommends coaxial cables for subwoofer, stereo audio, digital audio, etc. They state that, “The most important attributes of a line-level unbalanced audio cable are (1) shielding, and (2) capacitance. Heavy shielding protects audio signals from interference from outside sources. LC-1 Audio Cable uses a heavy double-braid shield, with one bare copper braid laid directly over another for extreme high coverage and high conductivity to ground; this is the identical shield configuration to Canare LV-77S, which tested best in our review of audio cable hum rejection characteristics (LC-1 hadn't been designed yet so wasn't tested at that time). By shrinking the center conductor to 25 AWG and foaming the polyethylene dielectric, we were able to get capacitance down to an extremely low 12.2 pF/ft, much better than LV-77S at 21 pF/ft. Capacitance can be important, particularly in long cable runs, because it contributes to rolloff of higher frequencies.”
What's better, one conductor or two conductors for an RCA interconnect?
I have a somewhat nice RCA analogue interconnect with one conductor, referred to as a coaxial Cable I guess. But I see higher end RCA cables with two conductors and ground wire. Which is better?
Is better detail provided when connections are made with two conductors?
I’ll second what @kijanki wrote. I have never encountered RCA connectors used with coaxial cables. I would expect coaxial cables to use BNC connectors, as I think someone else mentioned. The higher end cables, such as those that came from the factory with my Musical Fidelity turntable, are marked with a directional arrow, which I’m assuming points in the direction of the signal. It also denotes, for me, that the shield is only connected at the phono stage, not the turntable. The turntable does not have a three-conductor line plug 🔌 (which is a good thing to me), it uses a wall wart. The other thing to consider when selecting cables (aside from whether or not it is shielded), is its impedance rating in Ohms. Cables using the same connectors have different impedance ratings for use in either analog or digital applications. I can’t recall the values off the top of my head, but they will each ‘work’ in place of the other, but the energy transfer is not optimal and shouldn’t be considered for permanent installation. The same distinction holds true for XLR connectors; analog applications (I.e. ‘balanced’ connections) cables have impedance ratings which are different than those cables used in digital cables (I.e. AES/EBU connections). More experienced or knowledgeable members are free to correct or explain further the reasons for the difference I describe. If you’re purchasing cables, I would avoid coaxial cables using RCA connectors, if you are contemplating making your own, I would buy at least two-conductor shielded cable (I like Mogami), and consider using four conductor cable (twisted pair) together with the best connectors you can find. I have found good prices and fast delivery from B & H Photo, but would probably consider using one of the specialized cable companies mentioned on this forum the next go-round. Hope this helps
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But I see higher end RCA cables with two conductors and ground wire. @jumia Can you show an example of such cable? |
I did a experiment once.
I tried to measure if I could get any graph or see any benefits or difference between my trippel shielded (stated on the jacket) RCA and new bought but braided sterling silver RCA.
I wanted to see if there were ANY notable diffrence between them and I don't want to make things worse down the road and note that X hours later. I measured with the calibrated microphone and REW with the mic on stand. Then I switched out the triple one to the silver one and redo the measurements again with no other changes at all.
I sat down and compared the two measurements back and forth and really tried to find a difference somewhere/anywhere. I went through all 10-15 different types of graphs that I could find in REW and analyzed them and comparing them back and forth. That could give me any clue on what could be changed between differens shielded/braided or copper/silver.
I did not find anything at all only in one graph for impulse response that the silver had MAYBE a little bit better in that graph. But it's so small that probably needed to run 10 measurements on each cable and analyze those and see if there were any average measurements difference. Now with only one measument of each RCA the difference could be normal variation between measurements that i had noticed. Yes ot were not a big difference!
With all that said i just let the new silver cable be in the system when it anyway didn't had any negative effects.
Another conclusion as far as cable construction, crossection and geometry when they were totally different is that it didn't do any difference in this situation*. *Situation = if you have alot of RF in your place (near a radio station) or if you have low signal level as from TT to RIAA. That is a total different situations. And why some have totally different experiences.
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Interconnects can be a very important components in a system. The better the boxes in your system the more important the interconnects are. With cheap interconnects the actually materials are important and maybe the configuration. But as the cost goes up… as does the effort in getting better sound the less the specific materials and configurations determine the output. It is the effort put in to choosing materials and configuration. There are lots of ways to accomplish great sounding interconnects. In most cases one parameter will not determine the sound. It will be highly dependent on your system and the specific interconnects. |
Let me please clarify my statement from my earlier response. Your coaxial cable can also be used for digital signals. Such as from a transport or music server to your DAC. A good coaxial cable is important to have. Once you get into the analog world having a 2 wire RCA/SE or 3 wire XLR/Balanced cable is needed. Such as from a TT or DAC to your pre-amp. Joe Nies |
How would one know? Wouldn’t one have to try both first before answering this question? If two conductors happens to sound better, wouldn’t every cable manufacturer use this configuration? What brand of higher end RCA cables are made with 2 conductors and a ground? So many questions… |
When shield is used as return any electrical noise current induced in the shield will create voltage difference along it - between source/output and destination/input. Input will "see" the difference between output signal wire and output GND, plus noise voltage between both ends of the shield. |
Greetings If you have only one conductor that is a coaxial cable which is used for hooking up a antenna to a tuner or your cable TV or communication hookups. It probably would work but interconnect cables (RCA/SE) are 2 conductor with or without shield. Everyone of my RCA cables are 2 conductor. Some have shields some don’t. Try the Cable Company for a loaner RCA/SE cable so you can hear the difference for yourself. Joe Nies |
To clarify, I understand that there is one conductor, generally copper, and a shield which I guess also is considered a conductor. And then there are cables with 2 conductors, each a separate strand separately shielded. And then a third wire of sorts that acts as a drain or a ground. Is it better to have two separately shielded wires, which I guess can have multiple strands twisted around each other, versus a Single separately shielded copper wire? Higher extremely expensive analog interconnects have two conductors Plus a separate wire serving as a ground. If it don't matter for rca Cable purposes, ie. Unbalanced, why is it done. Presumably because it increases quality, and if so, why? |
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