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

[John Galt]

What is your opinion on RCA cables with directional shielding for use as standard RCA cables? Is it it a good idea just in case, and are there any known negatives to this design?

SVS states “Directional shield layer is a spiral braid of premium grade Aluminum foil and 56 strands of 99.99% OFC tinned copper Shielding – critical part of five-layer insulation system. Soldered to ground terminal at the source side helps reduce EMI and RF noise between electronics.”

https://www.svsound.com/products/soundpath-rca-audio-interconnect-cable

I’ve never heard about this before, but it sounds reasonable. I’m in the process of replacing all my RCA interconnects (subs, outboard amps to pre-outs) and would really appreciate your input on the topic.

I‘ve only had a ground loop hum on one cheap 15 foot RCA to a sub (easily resolved with new cable), and have not had any issues with my KabelDirekt or Mediabridge RCAs. Maybe all decent quality RCA cables have this feature? The fact that SVS cables have a directional indicator, where the cable is grounded at the source, and lifted at termination, got my interest.

Any thoughts on their shielded speaker cables? Any advantages or disadvantages?

As it is I have no 60 Hz hum issues, or detectable noise issues whatsoever.

Cheers!

 

[PaulD]

Marketing BS?

There has been a (partially) valid argument for shielding one end only of balanced cables, there was an article in Linear Audio about it a couple of years ago. For unbalanced cables it offers no benefits as there are only 2 conductors and both are used for the signal.

 

[John Galt]

Marketing BS?

There has been a (partially) valid argument for shielding one end only of balanced cables, there was an article in Linear Audio about it a couple of years ago. For unbalanced cables it offers no benefits as there are only 2 conductors and both are used for the signal.

I‘d assume that there must be three conductors in the SVS cable. Two for signal, and one for shielding, terminated at only one end.

 

[ta240]

I‘d assume that there must be three conductors in the SVS cable. Two for signal, and one for shielding, terminated at only one end.

The question is since the shield is terminated at the source side does the noise go back to ground through the source or proceed along the same ground terminal that is connected to the destination component? It seems like it would be easy to test with one of the cables like that purposely put in a very 'noisy' environment and switch which end the ground is on.

I'm going to be pissed when someone uses my idea and makes a high dollar cable like this, but why don't they have the shielding only connected to an external ground or even sent through a 'noise harvester' type setup to remove the noise. Think how much they could charge for that.

 

[PaulD]

I‘d assume that there must be three conductors in the SVS cable. Two for signal, and one for shielding, terminated at only one end.

So the shield is also connected to a signal conductor then... An RCA cable has only 2 conductors. You can put as many wires in there and connect them however you like, but it is an unbalanced 2 conductor cable. Only balanced cables might benefit from one end only shielding.

Also, Alu foil shielding is sometimes cheap and nasty. High density braided shielding works very well, although Shield and braid can work well together. Check Canare 2T2S or 4E6S cable for high quality shielding, as shown in the Benchmark video here:
https://benchmarkmedia.com/blogs/ap...-the-importance-of-star-quad-microphone-cable (although this is admittedly hi lighting the benefits of star-quad cable ofer normal twisted pair with a shield).

 

[somebodyelse]

https://www.jensen-transformers.com/application-notes/ - in particular take the time to read AN007 which, among other things, covers exactly what the shield is doing in different circumstances. You could skip to section 2.9 for what to look for in a cable for unbalanced connections, but the preceding sections give the background as to why. There's a similar explanation in another cable thread - different cable but chosen for similar properties. Back to AN007 section 3.6 for details of disconnecting the shield at one end of a balanced interconnect, and why it matters which end it is.

 

[solderdude]

I‘ve only had a ground loop hum on one cheap 15 foot RCA to a sub (easily resolved with new cable), and have not had any issues with my KabelDirekt or Mediabridge RCAs. Maybe all decent quality RCA cables have this feature? The fact that SVS cables have a directional indicator, where the cable is grounded at the source, and lifted at termination, got my interest.

So you are planning to replace cables that seem to work fine with cables of which you don't know whether they will work fine.

The cable is not 'lifted' at termination. ONLY the shield is lifted at the termination. The common signal that usually passes through the shield now passes through a wire. The shield still works as a shield though.

A technical problem could be when you are bothered by groundloops.
The common wire of the mentioned cable will have a higher resistance than when just the screen is used. Therefore ground loop currents will produce a higher 'unwanted signal' across the common wire which then becomes more audible.
It thus doesn't prevent or break groundloops, it potentially makes them worse.

You can just as easily have the shield connected to the receiving end and open at the source side. I would recommend to have the shield connected to the device with the least amount of common mode crap. Problem is you would need to measure that which isn't easy.

When normal shielded cables work fine, just keep using them. It won't improve the sound anyway and saves you money.

The speaker cables are not shielded b.t.w.

 

[pozz]

This cable is for situations where you need to break a ground loop.

Edit: @solderdude got there first.

 

[solderdude]

except that it does not break groundloops. The groundloop still exists (and may even be worse) as the shields of the RCA connectors are still connected but now through a higher resistance wire instead of the usually lower resistance shield ?

 

[Speedskater]

These RCA interconnects can have 20dB or more Common Impedance Coupling noise than a coax with a heavy braided shield.

 

[TankTop]

There’s lots of great theory here but I’m guessing that SVS sound path cables are well made and engineered and that alone will rectify the issue of a bad cable with a little shielding as a small bonus.

 

[solderdude]

There are also lots of proper shielded and well made and engineered and affordable cables around. Some of them will even be cheaper.
At least the cables are not in the audiphool price bracket.

 

[Speedskater]

I'm guessing the cable engineering experts would have the opposite opinion.
Experts like: Henry Ott, Keith Armstrong, Neil Muncy (RIP), Jim Brown & Bill Whitlock.

 

[Veri]

Eh, not digging the design of these SVS cables. Would take some mogami world's best cable over these any day, and they're priced similar or less.

 

[John Galt]

Eh, not digging the design of these SVS cables. Would take some mogami world's best cable over these any day, and they're priced similar or less.

What do you not like about the design? Do you think the SVS specifications are inferior in some way?

 

[Veri]

What do you not like about the design? Do you think the SVS specifications are inferior in some way?

No they're probably fine. They just remind me of these thick, un-flexible chinese Choseal cables I once owned. it's a personal thing

 

[Cbdb2]

Coax for unbalanced, shielded twisted pair for balanced. That extra shield will do very little, and may cause problems, it looks like an antenae at some RF freqs.

 

[somebodyelse]

What do you not like about the design? Do you think the SVS specifications are inferior in some way?

Mainly the shield connection. The shield resistance is 30mR/m, which would be a good thing if connected at both ends, but not if it's lifted at one end as solderdude pointed out. I first saw the twisted pair with shield only connected at one end on some Monster interconnects thrown in by a dealer 20+ years ago. They had some explanation that seemed to make sense at the time...

For comparison the Mogami mentioned by Veri and MC_RME is the W2964, or its dual version W2965. You can find the specs at the bottom of this page. Their W2893 starquad on the same page has the same 25mR/m shield resistance. Whitlock's suggestion is Belden 8241F which has lower resistance (8.5mR/m) and capacitance. It's nominally an analog video cable, so if it comes terminated you're more likely to find BNCs than RCAs.

 

[TLEDDY]

http://www.mogamicable.com/category/patch/

FYI

 

[John Galt]

I‘ll soon have Mogami for my LCR amps, and SVS for my dual subs.

Thank you for all the input.