Thoughts on RCA cables with ‘directional shielding’ e.g. SVS SoundPath

[napoleonblownafet]

An RCA cable with the screen connected at one end can actually reduce EMI interference and you'll notice this with a phono/turntable source. The idea of these cables is there are two cores and the screen is connected to one of them at one end. Because of this, the screen carries no signal EMF from the source and is simply working as a screen, not part of the signal carrying circuit. This has a number of benefits, particularly where small signals from turntables are highly vulnerable to EMI and such. You can actually buy these cables relatively inexpensivly and experiment. https://www.amazon.co.uk/RCA-Cable-...s=directional+rca+cable&qid=1638369254&sr=8-4

 

[Marc v E]

Aren't all rca cables basically the same? That's what my interpretation is of the test results by @amirm . https://www.audiosciencereview.com/...-of-rca-cables-mogami-amazon-monoprice.27871/

Looks to me rca cables are limited by their design to give distortion free sound up to 120db vs the signal. Xlr in my (limited) perception is better due to their design where they send a signal and the inverse signal. At the receiving end both are compared and the difference is then thrown away as this is probably noise or distortion.

 

[napoleonblownafet]

RCA cables are commonly a single-core with an outer screen connected at both ends. I would agree there is little to separate cables made this way, regardless of the chemical composition of the metals in the cable. This thread started by asking about directional RCA cables; specifically cables with two cores and a screen connected to one of the cores at one end only. This kind of construction has very different noise suppression characteristics, in particular where the receiving end is a very high impedance and the signal in the cable is very small - as with a turntable connected to an MM phono-stage.

 

[jcb]

RCA cables are commonly a single-core with an outer screen connected at both ends. I would agree there is little to separate cables made this way, regardless of the chemical composition of the metals in the cable. This thread started by asking about directional RCA cables; specifically cables with two cores and a screen connected to one of the cores at one end only. This kind of construction has very different noise suppression characteristics, in particular where the receiving end is a very high impedance and the signal in the cable is very small - as with a turntable connected to an MM phono-stage.

Makes sense, I’ve had good results with that type of cable for electric guitars, where the signal level is peanuts and the gain and input impedance is extremely high. The noise reduction with floating shield is substantial.

 

[napoleonblownafet]

@jcb - there you go! I spied another thread on this site where a poster called @pma tested a bunch of RCA cables. The clear winner was one such cable. https://www.audiosciencereview.com/...make-no-difference-thats-what-they-say.27920/

 

[Cbdb2]

You are missing the point. The shielding isn't directional in the way you seem to be suggesting. It is only connected at one end of the cable and it is recommended to be connected at source end. If you want to be pedantic you could say the shielding is directional as it can only flow in one direction since the connection is only at one end. As you see, there isn't anything magical about it.

Personally for best isolation I would rather see an external connector so the shielding can go directly to an earthing point.

First, device grounds at connections aren't perfect, there will be some impedance, and it will vary from device to device.
In unbalanced systems, in those directional ICs, the shield that is connected at one end to the source is also connected to the ground wire of the cable, which connects the shield to the ground of the receiver. So the shield is really connected to the ground of both source and receiver (by the ground wire in the IC). Where the noise ends up comes down to the difference in ground impedance of the source compared to the cable plus ground impedance of the receiver. Theres no guarantee the source has a lower ground impedance.

And a shield connected only at one end may be a better antennae making things worse.

Cartrages, mics, and guitars are balanced sources so the above doesn't work at all because the sources don't have a ground to attach to, just a neutral.

 

[Cbdb2]

Makes sense, I’ve had good results with that type of cable for electric guitars, where the signal level is peanuts and the gain and input impedance is extremely high. The noise reduction with floating shield is substantial.

Do you have a number for substantial? It has to be grounded at the reciever (amp) just like the regular shield. The only advantage is the double shield.

 

[Cbdb2]

@jcb - there you go! I spied another thread on this site where a poster called @pma tested a bunch of RCA cables. The clear winner was one such cable. https://www.audiosciencereview.com/...make-no-difference-thats-what-they-say.27920/

Where does it say its directional, or shield connected at one end? All I see is its double shielded.

 

[Lambda]

That's what my interpretation is of the test results

Well then your not interpreting the test right. like many others...

Looks to me rca cables are limited by their design to give distortion free sound up to 120db

No.

I first ran it with its internal loopback (i.e. no cable) and then with each cable connected. Here are the measurements of all the cables. None showed any change in noise spectrum, distortion, etc. (some run to run variation is there with is immaterial):

And even then, the level did not rise to audible levels (although my AP analyzer may be more immune to this noise than your audio gear). So assuming you avoid touching a transformer to your cables,

So you can’t test noises immunity of cables if you can't generate the Various types of noise. and your setup is immune to it because your using a 30k€ Analyzer.

Directional shielding can be better but not in combination wit twisted pair and Unbalanced RCA!
Coax is always better then Twisted pair for single ended signals. (in therms of Magnetic noise suppression.)

RCA cable Magnetic interference measurement and comparison

Cables are cables and there is no difference?! I designed a test to see if they perform significantly different in therms of "magnetic shielding" or Leakage inductance. This test dose not test for ground loop currents but interference from close by magnetic in homogeneous magnetic files. The...

www.audiosciencereview.com

If you want the advantages Directional shielding with RCA and Coax you need Triaxial.
Twisted Pair is only good for balanced signals and even then StarQuad is is better.

 

[jcb]

Do you have a number for substantial? It has to be grounded at the reciever (amp) just like the regular shield. The only advantage is the double shield.

No, but you can hear the difference almost as easily as turning your noise gate in the fx loop on and off. I don't understand the double shield, we're talking about this type of cable construction. 2 conductors plus shield, shield only connected to gnd (-) at one end. I don't fully understand the physics behind it but it is recommended for many types of equipment in my work (I'm an automation engineer)

 

[napoleonblownafet]

No, but you can hear the difference almost as easily as turning your noise gate in the fx loop on and off. I don't understand the double shield, we're talking about this type of cable construction. 2 conductors plus shield, shield only connected to gnd (-) at one end. I don't fully understand the physics behind it but it is recommended for many types of equipment in my work (I'm an automation engineer)

View attachment 170409

With a turntable and phono-amp, connect the screen to -ve at the amp end, not the tt/source end. You can ground the tt-chassis and tonearm to the shield and ditch that irritating little ground wire that so many turntables have!

 

[Cbdb2]

No, but you can hear the difference almost as easily as turning your noise gate in the fx loop on and off. I don't understand the double shield, we're talking about this type of cable construction. 2 conductors plus shield, shield only connected to gnd (-) at one end. I don't fully understand the physics behind it but it is recommended for many types of equipment in my work (I'm an automation engineer)

View attachment 170409

Dosnt most automation use ballanced lines?
First we need to know if the - in the pic is neutral (as in balanced ) or ground (as in unbalanced). If its neutral (which is usually shown as -) the diagram is wrong and the shield should not be attached there, but to ground. If the - means ground, the shield is also connected to the - (ground) of the amp by the black wire. If the amps internal impedance to ground is lower than the sources, most of the shield currents will still reach the amp. And if the source is dbl insulated (no ground pin) then all the shield current (including the source chasis) go back to the amp thru the neutral wire.

The main reason for shield attached at one end is to prevent ground loops, and that only applies to ballanced lines. The snake oil cable vendors have taken that, and corrupted it to useless BS.

Use normal coax for unbalanced thats all you need.

 

[napoleonblownafet]

This article seems to agree with @jcb 's explanation:

http://www.zinamp.co.uk/articles/TTCabling.html

 

[Cbdb2]

This article seems to agree with @jcb 's explanation:

http://www.zinamp.co.uk/articles/TTCabling.html

As I mentioned and they say tt cartrages are balanced so theres no ground, this is a special case in an unballanced system. This wiring is not the same as unballanced preamp to amp.

 

[napoleonblownafet]

As I mentioned and they say tt cartrages are balanced so theres no ground, this is a special case in an unballanced system. This wiring is not the same as unballanced preamp to amp.

Sure, but any ungrounded source - like a CD player with no earth-pin on its power cord - is balanced by the same definition

 

[Cbdb2]

Yes, so the currents from a shield connected to that source neutral only have one path path to ground, the receiver, thru the neutral connection. So again no point in shield connected to one end.

 

[napoleonblownafet]

Yes, so the currents from a shield connected to that source neutral only have one path path to ground, the receiver, thru the neutral connection. So again no point in shield connected to one end.

Well, don't knock it till you try it. It makes a very noticeable difference with a turntable (personal experience) and for the same reasons, can help with other sources too. It all depends on what the problem is in the first place. TTs tend to create hum because of small signals into high impedence. If your CD player isn't humming, you're unlikely to mess with cables for the sake of it

 

[SnakeOil]

Been using RCA cables bought from Emotiva. 2m $8.99 each. What would be the advantage of replacing them for more expensive cables. SVS 2m RCA $29.99 each

 

[somebodyelse]

Been using RCA cables bought from Emotiva. 2m $8.99 each. What would be the advantage of replacing them for more expensive cables. SVS 2m RCA $29.99 each

Unless you have a specific problem to solve, probably no advantage.

 

[bmwe39528i]

Well there's lots of arguments in every direction.

Here's my situation right now:

- Headunit completely disconnected and unplugged

-Vehicle off, engine off, ignition off

- RD400 JL amp connected to only one speaker

Keeping in mind all of the above, If I turn on the amp and connect one rca cable, right away I'm getting static from the speaker and tweeter.

If I ground the other end of the rca cable, the disconnected end, the end that would normally by plugged into a headunit, the static disappears!

So I have a clear and reproducible situation in which I can test any cable.

I welcome any company to send me an rca cable, and I will record a video/post results if that cable is any good getting rid of the static/ground issue!

So far I tried monoprice, Amazon basic and blue jeans cables, all are producing static!