Unshielded RCA cable is bad design

Here is a bit long article about HIFI system interconnect cables. There are pages promoting use of different unshielded cable constructions for HIFI systems interconnections. But the truth is that unshielded RCA cable is bad design and should be avoided. This article tells the truth about unshielded RCA cables, why they are bad and how many pages promoting them are wrong.

Nearly any signal that uses RCA connectors are considered line level. These are very weak signals (0.1-2V) and will pick up noise easily (unbalanced, output impedance can be up to 5000 ohms). RCA connectors are also used to carry sometimes phono signals, those are even weaker and will pick up noise even more easily than line level signals.

Interconnects with RCA plugs should be made with coax cable or shielded twisted pair cable to work well. Typically interconnects with RCA plugs are made with coax cable. The coax encases the signal wire in a pipe that protects it from interference.

1core-sh

Unshielded cable, like ordinary speaker wire or CAT5 UTP, is unsuitable cable for RCA interconnections. It will pick up noise very easily. This noise is usually heard as  a low level fuzz (less than totally silent background)  and obvious hum.

Your speaker level wires (with about 10-30 volts signal typically 8 ohm load impedance and fractions of ohms amplifier output) are much less sensitive to radiated noise than the RCA signal wires. That’s why they can live well without shielding.

Line level cables use considerably lower signal voltages and very much higher impedance, so they pick up noise more easily. For interconnects shielded construction is the way to go for line level RCA interconnects. Shielding on unbalanced interconnects does make a big difference in the background noise level.

Unshielded twisted pair cable, like CAT5 networking cable, is bad idea for RCA interconnects. It is true that due to its characteristic CAT5 and similar have low capacitance, but that’s where the good news end.

utp

You might have read that that UTP cable construction has good noise rejection characteristics and can carry signals well without shielding. CAT5 cables used in a computer network system are renowned for their ability to reject unwanted noises. It is true that twisted pair geometry works for the phone companies who run miles of cable and for Ethernet LANs very well without noise problems. Unshielded twisted pair works and rejects noise in those applications well because it is used in them to carry balanced signals.

Cat 5 and similar unshielded twisted pair (UTP) cables only work effectively when run as balanced lines where there are common-mode noise rejection properties built into the system. That common mode rejection is easily accomplished when the receiving circuit is passive (headphones or loudspeaker), transformer coupled, isolated and battery operated, or otherwise not referenced in any way to the transmitting-circuit common (either capacitively or resistively connected). For best performance the signal signal sending end should have same impedance from both signal wires to ground.

When you wire unshielded twisted pair to unbalanced signal source and receiver RCA connectors, most of the good properties of the UTP cable noise rejection are lost.  Unbalanced RCA interfaces found in normal HIFI equipment do not have common-mode noise rejection properties. The coupled noise will get to the signal on the cable. Therefore UTP is not effective for unbalanced home/consumer applications.Read Cat5 cable VS RCA cable for car stereo use article if you want to see test results.

There are also special unshielded braided unshielded cable construction made for HIFI interconnects. Those suffer from the same basic problems as the unshielded twisted pair cables, although some designs might offer a slightly better noise rejection characteristics than twisted pair. But they are still poorly shielded and should be avoided.

4play_plugs

(image from 4-Play)

Unshielded unbalanced cables are very sensitive to capacitive coupling especially when circuit impedance is high (impedance mostly determined by signal source output impedance in HIFI systems). For example power cords radiate a magnetic field and an electric field that is prone to carrying the interference that rides on all AC power lines to some extent. Shielding is an essential part of a proper RCA audio cable.  It is true that shielded cable has higher total cable capacitance than otherwise similar unshielded cable, but that’s the price you have to pay for the noise free sound.

The cable capacitance can affect the sound going through the cable. The most typical effect is that the cable capacitance together with signal source output impedance forms a low pass filter that more or less attenuates the highest frequencies. How much cable capacitance effect depends very much on the signal source output impedance (output impedance is typically in 30 ohms to 5000 ohms range, much bigger variation range than in capacitance of different audio cable types). If the signal source badly engineered, then the cable capacitance affects the signal source output driver amplifier stability, causing distortion and risk of oscillation at high cable capacitance. A well designed HIFIi equipment should be designed to cope with the normal cable capacitance. If the capacitance of normal shielded cable has considerable effect on the sound you get, there is something wrong with your signal source!

Some HIFI manufacturers (especially cable manufacturers that make such cables) say that unshielded unbalanced cables generally sound better than shielded (if your area does not have a lot of RF energy). If you are so lucky that you don’t have such noise sources nearby and like playing then you can try unshielded cable if you wish. Anyways in today’s high tech world  it is hard to find places without much RF energy nearby because for example cellular phones are very common and cause lots of noise if placed nearby unshielded cable. All well designed interconnects sound identical. Some interconnects are badly designed and do indeed sound different.

In today’s modern world you should always use shielded RCA cable. A coaxial design with a braided mesh shield is a good choice and braid shielded twisted pair is also good for making RCA cables. All well designed interconnects sound identical. Some interconnects are badly designed and do indeed sound different. Unshielded RCA cables are conceptually bad designs and should be avoided. Unshielded cables are OK only for applications that use balanced signals (professional audio), but even in those applications using shielded cables is the preferred.

117 Comments

  1. Tomi Engdahl says:

    https://www.stereonet.com/forums/topic/104285-shielded-vs-unshielded-and/

    There is no (sane) reason to choose unshielded interconnect cables.

    My thoughts as well. I was looking at the Aurealis website and he has more unshielded options than he does shielded ones. I thought maybe I was missing something and people had preferences for unshielded in particular circumstances

    There is no (sane) reason to choose unshielded interconnect cables.

    And no sane reason to discount unshielded, unless you have interference issues.

    If you are going from turntable then they will need to be shielded.

    Turntable to Phono amp needs to be shielded. Turntable to SUT needs to be shielded. SUT to phono amp needs to be shielded. Apart from that shielding is not essential unless you live in a high interference environment or run a snakes nest of cables as Muon said. Shielding will raise capacitance and when poorly implemented will dull your top end. My advice would be to try both and reach your own conclusion. There is no fundamental reason to choose a shielded cable when you don’t really need it. Most likely in situations where shielding isn’t essential you will get a better result with an unshielded cable. There really is no fundamental law about this.

    Reply
  2. Tomi Engdahl says:

    MEASUREMENTS: Analogue RCA Interconnects.
    http://archimago.blogspot.com/2013/05/measurements-analogue-rca-interconnects.html

    Summary:
    1. Analogue ain’t digital! Although in most ways the measurements are very similar (these are short lengths of interconnects after all), mild differences can be found.

    2. Frequency response unchanged among the cables. Interesting. Some people talk about analogue cables as “tone control”. I don’t see it using these interconnects even with longer length (there is a hint of high frequency roll-off with the 16′ cable but really this is trivial) or different conductor material. Using silver interconnects, there are no changes in the frequency response to suggest these cables sound “brighter” as some contend :-).

    3. Interesting Stereo Crosstalk performance. Stereo crosstalk looks to be sensitive to cable length. The silver cable had the least crosstalk up to 5kHz and then increased from there – this is possibly a function of the fact that it’s constructed as 2 separate cables as pictured above rather than the zip-cord arrangement of the other cables.

    4. Measures like THD should not (and in fact does not) show a difference. After all, cables are passive “components” so should not introduce harmonics into the equation. As for noise floor, I suspect if I were to test under conditions with strong RF noise the poorly shielded cables would perform worse (may try this later), but in the home environment where I tested, obviously this was not a problem even in reasonably close proximity to the laptop, DAC, and E-MU ADC.

    There you go. Analogue interconnects do make a slight difference and this is quite measurable particularly in terms of stereo crosstalk performance. Remember that these interconnects are of relatively short lengths so minor differences are really not surprising. The obvious question is – would humans be able to differentiate these interconnect cables based on listening tests? I honestly doubt it. Subjective listening using my test setup did not reveal any noticeable change with the long cable vs. the short silver cable. Realize that even with the long 16′ cable, stereo crosstalk was still below -75dB which should be inaudible – for comparison, high-end LP cartridges are only capable of 30-40dB crosstalk performance.

    Reply
  3. Tomi Engdahl says:

    https://www.stereonet.com/forums/topic/104285-shielded-vs-unshielded-and/

    My comments come from this line of thought (nothing to do with the sound of tube amps vs. ss amps):

    If you have a low bandwidth amp then unshielded interconnects will not be a problem.
    If you have a high bandwidth amp then unshielded interconnects will be a problem – so you need to use shielded interconnects.
    So people who use unshielded interconnects with no problems are those who have low bandwidth amps.
    Tube amps can certainly be low bandwidth … ss amps less likely to be.
    SS amps can have a much greater bandwidth than even the widest-bandwidth tube amps employing output transformers. (I don’t know what the bandwidth specs are for those rare breed of OTL tube amps.)

    Tube amps can also be wide-bandwidth

    My comments come from this line of thought (nothing to do with the sound of tube amps vs. ss amps):

    If you have a low bandwidth amp then unshielded interconnects will not be a problem.

    Incorrect. 50Hz hum can be an issue with unshielded interconnects. As can RF interference. However, LOW impedance terminations can mitigate these problems. In ALL cases, unshielded interconnects should NOT be used for audio systems.

    You are assuming that there will! be interference to pick up….why are you guaranteeing this?

    Because even if you live well away from an airport (and its radar), there is all the wifi which surrounds us.

    And 50Hz mains interference, as ZB has just pointed out.

    50Hz is mains isn’t it?

    So unless you like your signal cables near mains power interference sources?

    And while I have much respect for Trevor, I think from my own experience that this thing that unshielded cables should never be used in audio is incorrect.

    It really depends on the system and how it is put together IMO.

    Sure, M – and if you’re running low bandwidth tube amps … you will never have a problem!
    Providing, of course, you keep your power cords away from your unshielded interconnects.
    Now you are mixing the two things up, 50Hz is not high, very low actually

    Of course. Microwave radiation can be a major problem. Particularly with SS equipment. RF can enter equipment and is rectified by semiconductor junctions, thus causing interference.

    Measurements would be nice!

    A quick look around finds most people commenting on cables are “subjective”…

    This looks mostly at cheap cables, and finds that they are good enough – and that a fair few claims don’t fly.

    http://archimago.blogspot.com.au/2013/05/measurements-analogue-rca-interconnects.html

    Note that shielded cables don’t actually dull the high end of the audio frequency range and that crosstalk is better than that found in many components, even with the cheapest cable tested.

    So, does anyone have other measurements to contradict this? I’d be interested to see them.

    An interesting article and about the only one out there. And you are correct – it’s all very much subjective experience on the thread. I do wonder how accurate Archimago’s equipment was, and whether most of what he was measuring was clouded by the limitations in the equipment. I only say this because I have looked into buying accurate equipment for cable testing and it runs into many thousands of dollars, which was way beyond my budget.

    The whole thread should possibly moved over into a new one entitled “Experiences with Shielded and Non-Shielded Cables”.

    I have a strong opinion on this topic and my view is that there is no rational reason to compromise your system performance with unshielded cables. Any theoretical benefit is outweighed by multiple source of interference.

    No matter how simple or structured your wiring loom is, the reality is that EM and RF injection is everywhere. Even if your room is insulated like a faraday cage, there remains the issue of component to component interference.

    For example, why would you use an unshielded power cable? There is a vendor out there who markets heavily on his self-proclaimed proprietary pseudo-science that has such a cable which emits an EM field radius in excess of 200mm. That is not a good performance outcome for most typical systems.

    I use unshielded RCAs in parts of my system.

    So now I’m wondering about what is it that I’m meant to be hearing from these poor cousins?

    If shielding is a must why would a company like Kimber invest so much research into achieving a shielding effect by its configuration and expensive equipment to produce it?

    Why wouldn’t they just bung a foil or such likes around it?

    Does twisted pair, three wire braid, multiple wire braids not offer anything to immunity?

    What are the negative effects of shielding on a cable?

    How would one go about shielding an unshielded cable to experience what shielding offers?

    One’s bliss can be another’s poison.

    An unshielded and unbalanced cable has the greatest potential of having its signal altered by EM/RF pollution.

    So is this issue audible with unshielded cables or only noticed when you use shielded cables and realise the difference.

    It’s all system dependent, I have no interference issue when using unshielded line level IC’s

    It’s true, when it comes to cabling, I am militant. I take my queue from the aerospace industry by eliminating the risk to begin with. I love products shielded with Kapton. I love Techflex solutions. Products built around such technologies have been proven to be successful with low risk outcomes.

    One’s bliss can be another’s poison.

    An unshielded and unbalanced line cable has the greatest potential of having its signal altered by EM/RF pollution.

    This is true except I would take out the word “greatest” and run it as “An unshielded and unbalanced cable has the potential of having its signal altered by EM/RF pollution.”

    Totally agree. But the shield in a shielded cable will also add some distortion to the audio signal. Which distortion do you prefer? It’s subjective, you make the choice from listening.

    I don’t think I do either but from what a lot are saying the system has to be getting interfered with and is detrimental.

    It only has to be subtle before you begin losing background blackness and depth of presence. Over time, one can easily become accustomed to something less without realising anything was even missing.

    I guess i wouldn’t know as i have no issues with interference..

    I have no issues from interference either and I live 1.5 kilometres away from Brisbane’s main TV and radio transmitters. But if I am getting distortion effects from RFI they are good ones as I still prefer what is happening compared to using heavily shielded cables.

    So we risk interference with an unshielded cable and distortion from a shielded cable.

    So how do we know with a shielded cable that something isn’t missing due to the distortion?

    Yeah, That’s an aspect i would notice, especially going back and forth between shielded and unshielded IC’s but have not detected any lose with unshileded here.

    I use unshielded RCAs in parts of my system.

    So now I’m wondering about what is it that I’m meant to be hearing from these poor cousins?

    You need to do the experiment. Substitute shielded RCA cables for the unshielded ones you are using now (preferably from the same mfr, so there is some similarity in their construction) and see what sound difference there is. Preferably, don’t do this by yourself but invite 3 or 4 keen-eared listeners around.

    An unshielded and unbalanced line cable has the greatest potential of having its signal altered by EM/RF pollution.

    Absloootely!

    If shielding is a must why would a company like Kimber invest so much research into achieving a shielding effect by its configuration and expensive equipment to produce it?

    Why wouldn’t they just bung a foil or such likes around it?

    Does twisted pair, three wire braid, multiple wire braids not offer anything to immunity?

    What are the negative effects of shielding on a cable?

    How would one go about shielding an unshielded cable to experience what shielding offers?

    Because they decided the market segment they wanted to own was braided ICs – not shielded ICs. Braiding/twisting wires certainly does provide some immunity to RFI (compared to unshielded cable) but an experiment can easily be done to show how much this is:

    for a phono cable – the lowest signal level in your system – compare one which, say, has 2x twisted pairs (1 for each channel) against one which is made of coax – so shielded. See if the sound is different.

    The negative effect of shielding a cable is higher capacitance – which, supposedly, results in a “closed-in” sound.

    But it is pretty hard to shield an unshielded cable – the shielding is kind-of intrinsic … but it can be done.

    Totally agree. But the shield in a shielded cable will also add some distortion to the audio signal. Which distortion do you prefer? It’s subjective, you make the choice from listening.

    Certainly – it’s A vs. B … and whether the negative effect from A outweighs the negative effect of B.

    But I’m interested to know what your view of the negative effect of shielding is.

    Your system is getting distorted in so many ways. Which distortion do you prefer? From the way this thread has been running it seems clear that Brisbane has the most pleasant distortion from EMI/RFI on the whole eastern coast. And it’s probably true. Want your system to sound better, move to Brisbane!

    An interesting article and about the only one out there. And you are correct – it’s all very much subjective experience on the thread. I do wonder how accurate Archimago’s equipment was, and whether most of what he was measuring was clouded by the limitations in the equipment. I only say this because I have looked into buying accurate equipment for cable testing and it runs into many thousands of dollars, which was way beyond my budget.

    The whole thread should possibly moved over into a new one entitled “Experiences with Shielded and Non-Shielded Cables”.

    Thanks for posting this.

    So why do those people who do own suitable equipment – and I include all of those magazines who measure components regularly – never publish cable measurements? And surely, if his equipment was poor, it would show up as poorer performance than the evenly good quality shown in his test? I can’t see how anything “better” than these cables would give us an audible change. While the measurements are limited, they do address the two areas quoted by supporters of unshielded cables- stereo imaging (crosstalk) and frequency response differences, at least in the audible range.

    So from a few posts I have picked up that shielding adds to capacitance and results in a closed in sound and lower back ground noise.

    Unshielded cable has lower capacitance and therefore a more open sound but has a higher back ground noise.

    It seems that if the interference levels are not high then a more open sound would be better than a closed in sound assuming back ground noise is not intrusive?

    You ask a good question there. I don’t think those magazines have the accurate equipment that are needed to test cables. I have looked into it and they cost way more money than you’d expect. Thousands of dollars. I have an accurate LCR meter and every time I use it I need to run two 30 second tests on it. Those tests measure the internal resistance, capacitance and inductance of the meter and then zero it, so the internal measurements do not impact on the measurements I make on my cables. A similar instrument that would cut out the internal frequency response, etc of the measuring instrument would cost a huge amount of money. Even with LCR meters, the accuracy of what they can do for $200 has only improved in the last 5 years due to advances in technology.

    Is the shielded cable people are referring to a coax i.e. signal as the inner conductor and the ground/return conductor is the shield

    OR

    Two cores as conductors with a shield around them that is grounded at the source end?

    accurate LCR meter

    Ah, I see. This is useful to quantify the properties of a cable itself….. but doesn’t say anything specifically about what happens to a signal you pass through a cable (which is what matters).

    Measuring the signal as it enters and leaves a cable (and quantifying the distortion), is the primary measurement of interest? Yes? (at least in so far as quantifying how much a cable is distorting a signal passing through it)

    Post 14 of this thread provided this link: http://archimago.blogspot.com.au/2013/05/measurements-analogue-rca-interconnects.html

    The conclusion contridicts what I’ve experience and it doesn’t explain why I hear a difference between cables, maybe it’s all in my head, but I’m sure the ear is an interesting set of test instruments. That said I will always use shielded cables.

    No unshielded cables for these set of ears…

    I have just bought a new used turntable where the tonearm cable is RCA to RCA. The current cable is 35 odd years old so have tried a couple of cables – the one that sounded best was KImber KCAG silver cable and it’s very flexible. the KCAG is unshielded I believe.

    Only problem, it had noise – buzzing that can be heard at high volumes – when music is not playing – but once heard it always nags in the back of your mind.

    As a bit of a joke experiment I wrapped the cables in kitchen aluminium foil – now NO NOISE – LOL looks like a joke, but works very well. Can’t say there was any immediate sonic downside either – but I have not really done any A – B listening.

    What are the other better and easy options available to shield? without any sonic downside

    Reply
  4. Tomi Engdahl says:

    https://www.stereonet.com/forums/topic/104285-shielded-vs-unshielded-and/page/4/

    I have just bought a new used turntable where the tonearm cable is RCA to RCA. The current cable is 35 odd years old so have tried a couple of cables – the one that sounded best was KImber KCAG silver cable and it’s very flexible. the KCAG is unshielded I believe.

    Only problem, it had noise – buzzing that can be heard at high volumes – when music is not playing – but once heard it always nags in the back of your mind.

    As a bit of a joke experiment I wrapped the cables in kitchen aluminium foil – now NO NOISE – LOL looks like a joke, but works very well. Can’t say there was any immediate sonic downside either – but I have not really done any A – B listening.

    What are the other better and easy options available to shield? without any sonic downside

    Never, EVER try to use unshielded interconnects with phono cables. The result will always be tears. You could buy some copper braid and thread the cables through it. A cheap solution might be to buy some RG213/U, strip the insulation from the outside, remove the braid and use that. Lots of work, but a cheap, easy to find solution.

    If you bought these online and they shipped from China, I hope they were very cheap as they are most likely fakes.

    I had a noise problem with the in built tonearm to phono stage cable on my Technics SL7. I used a product called Wrapshield made by Holland Shielding Systems. Just wrap the cable with a 50% overlap and secure with tape or shrink tubing. Not a peep of noise since.

    Hi Shane, no negative impact to the sonics at all. Before the wrap, the cables injected noise any time they were running near any other cables and particularly power cables and interconnects. After wrapping, there was zero noise regardless of placement.

    I have a spare set of Mogami rca to rca phono cables that I wrapped with the excess wrap I had left over – just need to add some shrink tubing to cover the unsightly tape job I did as a temporary binding. You’re more than welcome to borrow them to see how they go with your system.

    Says you living under all those TV tower thingies!

    You need to come to the South Side where the air is truly pure :)

    Very true, only a couple of kilometres away from them. And never had any issues with unshielded cables, apart from the obvious: shielded cables are essential for TT to SUT and SUT to phono amp link. But it’s possible that the “Faraday Fence” the guy built across the road adds some benefits.

    I also am using supermarket aluminium foil wrapped around my unshielded RCA cables that connect my short plug phono leads to my pre-amp. Without it, I get a bad hum through the system.

    The Wrapshield option sounds a good one to try…but before I do though, does anyone know or have an opinion on whether copper foil tape might be just as effective in reducing earth hum?

    I have some double-sided conductive copper foil tape that I could try, but as it has a fairly strong adhesive I thought I would ask the question first rather than waste it if it wont work for some reason…

    Hensa, do you mind if I ask how much the Wrapshield tape cost you, including shipping?

    I wouldn’t use adhesive backed foil as the overlapped layers won’t slide and allow the cable to bend.

    Hensa, do you mind if I ask how much the Wrapshield tape cost you, including shipping?

    I got it a few years ago and have no recollection what it cost but it was not expensive – maybe $40 to $50 landed for a 10m roll but it’s only a guess.

    Did you run a pigtail from the wrapshield to ground? We used to use stacks of this stuff to shield EMI (in and out) on aircraft system cables.

    I’d like to say yes but don’t actually know what that means so in all likelihood, no. In any event, the goal was to eliminate noise getting in through the cables and it is now totally silent.

    For the shield to be effective, it needs a connection to signal ground. Normally this is achieved by soldering a pigtail wire to the braid, which is connected to ground, or the braid is clamped by a metal backshell of the connector, which is in contact with ground.

    For the shield to be effective, it needs a connection to signal ground. Normally this is achieved by soldering a pigtail wire to the braid, which is connected to ground, or the braid is clamped by a metal backshell of the connector, which is in contact with ground.

    Good to know – thanks. Still, it is totally effective at stopping the unwanted noise through the system without such a connection to ground so all good.

    EMF shielding should use the most conductive materials available. That usually means copper. I don’t understand the attraction of unshielded cables. Just use braid and foil shielded cables and you shouldn’t have any problems. They are available in a very wide range of price points, brands and colours.

    I am using a separate earth wire, so that is covered. Only the Kimber KCAG had any noise out of the 3 cables I used.

    Hey Metal Beat,

    I tried out the adhesive copper foil tape and it works really well.

    As its self adhesive, it is much easier to apply in an almost shrink wrap tight fit around the cables.

    SO much better than the aluminium foil solution!

    Hi,

    ‘Spray on shielding’ ?

    I have a little hum from my system and thought the cause were my interconnects as I thought they were unshielded.

    It turns out that the hum is from my preamp power unit (powering my preamp) and then I remembered that I had bought the interconnects from my friend (who has since passed away) and he said that those particular interconnects required no further ‘shielding’ because they had been treated/sprayed with something that created a ‘shielding’;

    Does anyone have any knowledge about what that may be ?

    Oh,

    I had some braiding that I tried on my interconnects last night and I think the sound is worse. Less ‘alive’ and not as dynamic. The braiding was some ‘plastic’ audio braiding. I also have some cotton sleeve type braid. I’ll try that on the weekend.

    Reply
  5. Tomi Engdahl says:

    Is shielding necessary on interconnects & speaker cables
    https://forum.audiogon.com/discussions/is-shielding-necessary-on-interconnects-speaker-cables

    Shielding is a means of preventing RF and EMI from disturbing/distorting the signal within a cable’s conductor. This is far more important in an interconnect than a speaker cable due to the relative power of the signal. RF and EMI can also be prevented from harming the signal in an interconnect by the geometry of the weave. SO – simple answer is don’t bother looking for shielded speaker cables and either use a shielded interconnect or one with a proven track record of good geometry like Kimber Kable.

    A lot of cable designers skip the shield in their cables. Teo Audio, Sablon Audio and Acoustic BBQ are at least three brands that fall into this category. They report the SQ as being more lively.

    Noise vs. capacitance.

    Most people are fine with unshielded.
    The shield in a cable acts as a capacitor plate, so it may introduce some rolloff, which may be desirable.

    Shielding is not needed most of the time as it can hurt the sound. Shielding can close in the sound and darken it. Now if you need a phono cable from your turntable then shield it! That is the only time I shield with RCA or single ended ICs.

    No need to shield speaker cables.

    its best to not use shielding…closes in the sound. If you need it, you need it.

    Your best bet with anything like this is to leave that choice to the professionals. In other words do not look for shielded or unshielded. Don’t give it a moments consideration. Look only for what sounds good.

    Other than phono cables where the signal is in millivolts so must be shielded its unlikely you’ll find a shielded interconnect you prefer. But if you do, buy it. Buy the sound not the theory. Every. Single. Time.

    It depends on your situation. I made a 12’ unshielded RCA cable and I have no issues with noise. They sound great! They don’t run next to anything that would induce noise however. You might consider shielding if that weren’t the case.

    Reply
  6. Tomi Engdahl says:

    Shielded or Unshielded analog audio cables
    https://www.techpowerup.com/forums/threads/shielded-or-unshielded-analog-audio-cables.261629/

    Is there a noticeable difference in sound using shielded vs unshielded for ultra high quality audio (like dsd or flac)? Cable in question is a 3ft 3.5mm to 3.5mm.

    I’m asking because my headphones use an unshielded cable, I got an unshielded patch cable today and it sounds really clear but I can’t exactly easily compare it with a shielded one, is there really a difference? I read that shielding causes induction so is a generic (copper) unshielded cable really better than the shielded variety for analog sound?

    From Vovox cables “For studios we generally suggest to use unshielded balanced cables as they offer better sound quality.”

    Is there any truth to this?

    Yes. Balanced cables feature two streams that crosscheck each other and cancel out literally all noise attributable to interference, making shielding useless. Unbalanced cables generally benefit from shielding.

    There is no way you can use balanced cables without expensive gear though, they don’t work with standard input/outputs like stereojack or RCA. Just get some average shielded, unbalanced cables and call it a day. Monoprice RCA or similar is fine. Thank me later.

    I’m still considering buying some blank ends and some silver wire and making my own, would be far cheaper than the pricetag on some of the high end audio stuff, and silver is the best afaik for analog sound.

    Still going to be like a .01% return, but yes, better pricing than commercial. Keep in mind silver is stiff. I know from the example below:

    I have a reel of 12 gauge silver wire (yes, large stuff, used it for battery electrodes) I used in a chemistry experiment a bit back if it helps, still a fair bit left, I think a troy ounce worth. Would sell for sub scrap rate given even pawn shops here won’t take it without a mark (despite me explaining they could just uh… weigh it to confirm it’s silver).

    Wouldn’t help a ton but you could play with it cheaply. I’d basically just ask shipping.

    Reply
  7. Tomi Engdahl says:

    Unshielded vs Shielded analogue Interconnects.
    https://www.youtube.com/watch?v=IoRuUSuo7iE

    Comparing the two different designs.

    Reply
  8. Tomi Engdahl says:

    https://www.techpowerup.com/forums/threads/shielded-or-unshielded-analog-audio-cables.261629/

    Using shielded cable for a 3 ft headphone connection is absolutely useless. Headphone output is low-impedance with strong signal.
    Shielded cables matter when you are dealing with very weak to weak signals (microphone to mic. amp., mic amp to power amp. / mixer table / PC).

    Also, is your headphone output balanced? 3.5 mm jacks are generally unbalanced (left, right and common). The only way to get balanced output from a 3.5 mm jack is to have only one channel.

    The thing is that conductivity isn’t what helps the sound. Capacitance is. Low capacitance = less high frequency roll-off in a long cable run.

    Thing is, even then, you’re talking upwards of 30 feet before the difference is really audible, and that’s with high-impedance sources like guitar pickups, which are more susceptible.

    In a buffered circuit or a short length, you’ll hear no difference unless you’re going big placebo.

    Shielded is better protection to get better quality but you can’t rely on that alone, first you need to separate power and sound cable to avoid any interfere

    Are you talking about passive headphones? That’s already an amplified signal, there is no need for shielding – shielding is to prevent interference from entering a line-level cable so that it doesn’t get amplified at a later stage – with no amplification, it can’t be heard.

    Balanced cables are also for line-level signals.

    A 3-foot cable being used after a power amplifier would have so little resistance and capacitance that I doubt using silver would have any effect at all on the sound quality. You would be better off experimenting with various gauges of copper.

    Don’t go too large though because headphone amplifiers are very low power and will have a difficult time driving thick wire. I probably wouldn’t go smaller than 20, but something in the 22-28 range would probably be good. If you do use silver, the upper end of that range would be fine.

    There is also the option of silver plated copper. AC signals (which audio signals are) have a “skin effect” where it travels mostly on the outermost surface of a conductor, so you would get some of the benefit of silver while saving quite a bit on the cost. There is also the litz wire mentioned in that article available for audio purposes but I think that gets pretty expensive.

    Neither the silver plated, nor the litz wire, have an audible effect, and certainly not over such short distances.

    Litz wire is good for ensuring signal integrity in some cases, but it’s effects are only really beneficial at frequencies below hundreds of KHz. For audio it’s useless.

    The silver plate is also effectively useless, it just… doesn’t actually do anything. And even if it did it would only do it over much longer distances than we’re talking about here.

    Reply
  9. Tomi Engdahl says:

    Test of cable shielding, does it matter
    https://www.audiosciencereview.com/forum/index.php?threads/test-of-cable-shielding-does-it-matter.20538/

    After seeing this video I made sure every cable I bought for my system was shielded.

    Is that proper form? Does it make a difference to use shielded cables?

    No.
    Long answer, your equipment should be shielded. but if its not… unlikely but maybe in some special cases.
    This is snake oil.

    There is no reason for the cables to be garden hoses size and or expensive
    Propper Lapp cable with shielding is maybe 15$ +2*20$ for audiofool Rhodium platted beryllium copper connectors.

    so maybe 60$ to have a nice looking cable but dont expect to hear a difference

    Does it make a difference to use shielded cables?

    If you have long interconnectors (say, longer than 6 or 7m) between source (dac) and amp, the quality of the shielding comes into play – not well shielded cable may pick up noise which then gets amplified. So, the cable before the amp is critical.

    Edit: Well shielded cable doesn’t have to be expensive. Buy it per meter/inch – so that you can see how dense the braid around the inner cables is. (If you’ve got a soldering iron.)

    Certainly for low level signals, like turntable to phono pre they can make a difference. Below is a noise floor comparison of two cables into a Project DS2 phono stage in mm mode, measured on it’s output. Even changing power supplies made small differences. The kimber is an unshielded, tri-twist type of cable. Project is shielded with connection at amp end only.

    Hello,

    Shielding of low level signal cables makes some sense, the lower the signal level (phono signals) the more sense it makes. However shielding the last four feet of power cables is pretty much nuts. What about the other 99.999% of the power cables in the wall and back to the electric company?

    Shielded mains cables (the wires themselves) are cheap and can lower radiated emission.
    They are specifically handy when one has to drive speed controlled heavy duty motors with servo control wires running alongside those power cables.
    The trick is to ground them properly for HF. This is not the same as safety ground which serves a totally different purpose.
    Proper HF screening is basically creating an extended Faraday cage between 2 connected devices.
    When one device is properly EMC screened (audio equipment can be but isn’t any more the moment you connect a cable) what a proper screen will do is basically elongate the cabinet’s enclosure right up to and around the transducer. The latter can be a pickup or something that is driven.

    Anyway… back to mains cables. Suppose one has a screened mains cable that is connected to safety ground with a short wire inside the amp.
    That short piece of wire (several cm) is an inductor (high resistance) for frequencies used n cell phones etc. It works like a good connection for audible frequencies and well above that.
    So the screen is basically an extension of the metal amp enclosure. It also works well as safety ground. The latter is the purpose of the green/yellow cable and why that is (should be) connected to the enclosure.

    As the video showed the detector cannot detect the mains (audible range + several harmonics) on the cable any more. Regardless if current flows or not. So yes it does screen (reduce dramatically) LF fields but does a poorer job for very HF signals.

    Suppose we have a nice rack and someone decided to use poorly screened interlinks for instance and to make it neat ties all these wires in one nice bundle then the screened mains cables might actually help lower induced hum in the audio cables.

    Keeping mains and audio cables separated at least a few cm and only cross them at 90 degree angle will help reduce coupling effectively. There is no need for screening mains cables.

    Having one screened cable (for the power amp for instance) running along side generic mains cables in the same bundle is pointless.

    Hello,

    Shielding of low level signal cables makes some sense, the lower the signal level (phono signals) the more sense it makes. However shielding the last four feet of power cables is pretty much nuts. What about the other 99.999% of the power cables in the wall and back to the electric company?

    Regards,
    Greg

    It’s not just phono signals that are susceptible. CD players, Blu Ray players, amplifiers etc are impacted.

    Shielding power cables in your room makes a lot of sense as you want to keep the area around your equipment as clean as possible. Unfortunately at best it is only likely to reduce atmospheric contamination by a certain amount, so if you are really serious you would shield all cables; both power and interconnects, even if the are shielded as the shield is often the return signal. As solderdude alluded, unused ports act like antennas with a direct path to circuit boards, so it’s a good idea to fit dummy shielding plugs to address that issue. Going further, most equipment creates its own problems and internal power supplies should be shielded as much as possible.

    I also noticed that solderdude questioned the benefit of shielding speaker cables when the cables in speaker enclosures aren’t. An interesting issue for consideration. So should the cables and crossovers be shielded?

    Atmospheric contamination is real and should be taken seriously, not dismissed as snake oil.

    After all, I’m sure you’ve heard static noise on AM radio; it’s particularly bad around trams due to noisy power supply. Shielding that type of atmospheric contamination might be something worth considering.

    Don’t take my word for it. Give it a try and you might learn something.

    Shielding from influences in the ether can only be done by a Faraday cage that may have holes sized to the min allowed HF leakage.
    This is not feasible in an apartment. ‘Electrosmog’ is all around us and it’s up to the manufacturers job to comply to certain immunity limits.
    Limits that can only be reached when devices are connected using proper cables.

    When mains and speaker cables would really need this there would only be fully shielded mains connectors, wall wiring would be screened, speakers would have metal grounded enclosures and speaker cable connections would be screened.
    They are not, and for good reason… it isn’t needed in 99.999% of home audio installations. The remaining 0.001% requires special attention and will require more than screened speaker/mains cables.

    Hum Rejection in Unbalanced Audio Cables
    http://www.bluejeanscable.com/articles/humrejection.htm

    Reply
  10. Tomi Engdahl says:

    Should a balanced interconnect be shielded as well (shielded vs twisted pair)
    https://www.audiosciencereview.com/forum/index.php?threads/should-a-balanced-interconnect-be-shielded-as-well-shielded-vs-twisted-pair.20254/

    The has been some success in the pro audio field using unshielded Cat5 cable.
    But CAt5 is vary, vary different from non-shielded single braided cable, in which the positive, negative, and the two ground are all twisted together.
    On the other hand, balanced XLR interconnects are a very robust system. For a 1 or 2 meter interconnect almost any cable will work.

    Ghent cables are shielded using two sperate shielded cables for the positive and negative signals of the balanced connection. Ghent told me this is the best approach.

    That’s the _worst_ way of making a balanced connection. The proper way is twisted positive/negative signal wires surrounded by a shield.

    In one method you improve the CMRR with tight twisting. Star quad helps even more. In the other you reduce the CMRR somewhat by shielding the twisted wires from each other so the fields can’t cancel out. Maybe too much CMRR is like too much negative feedback. You have to listen and read the advertising instructions to know for sure.

    Balanced lines’ rejection bandwidth depends upon the twisting and spacing of the twisted pairs. The shield provides additional protection from EMI/RFI and additionally provides a separate (chassis) ground path for reducing externally impinging noise upon the signal conductors. Ideally the shield creates a (quasi) Faraday cage protecting the signal conductors within.

    Balanced XLR is about as good as it gets, provided proper grounding technique is observed in all the components in the system. The theory and practice of this were established by Neil Muncy in his classic 1995 article, which was later put into the AES48 standard. This article by Bruno Putzeys explains it further.

    Balanced XLR is about as good as it gets, provided proper grounding technique is observed in all the components in the system. The theory and practice of this were established by Neil Muncy in his classic 1995 article, which was later put into the AES48 standard. This article by Bruno Putzeys explains it further.

    CMRR IN BALANCED INTERFACES: part 2
    https://www.svconline.com/news/cmrr-balanced-interfaces-part-2-369515

    A balanced interface can reject any interference whether because of ground voltage differences, magnetic fields, or electric fields as long as that interference

    The guy from the video (Guntars) told me that his connections are very short, thus no shielding is required, and longer shielded cabled will add capacitance, which will reduce the bandwidth. Ghent told me that for BTL, he can make me a shielded cable in which both pos/neg conductors are inside the same shield.

    Also, have anyone noticed that for balanced headphones cables. the most expensive ones are braided and not shielded? So I’m still not sure what is the best balanced cable configuration. Twist or twist and shield? Also, do you ground the shield on sending/receiving end, or both?

    Each article gives a different suggestion…

    The guy from the video (Guntars) told me that his connections are very short, thus no shielding is required, and longer shielded cabled will add capacitance, which will reduce the bandwidth.

    Nonsense. Sure, a shield increases the capacitance a little, but that doesn’t matter. Cat 8 Ethernet cable uses shielded twisted pair and has a bandwidth of several GHz.

    The guy from the video (Guntars) told me that his connections are very short, thus no shielding is required, and longer shielded cabled will add capacitance, which will reduce the bandwidth.

    Pros often use 100 meter (300 foot) XLR cables (and sometimes much longer) at on location sites with no capacitance problems.

    IME most “hum” problems stemmed from ground loops, or poor grounding (return path) execution in general that was outside the CMRR path, which matches that completely.

    Mogami quad-star cable is around 35 pF/ft to the shield and 24 AWG (0.04 ohms/ft). Given a preamp with 600-ohm output impedance (on the high side) and 100 k-ohm amplifier input impedance, here is a quick simulation showing 500 feet of cable yields about 450 kHz of bandwidth considering just one wire to the shield. This is not a full simulation with distributed RC and all that jazz, but seems like it should not be an issue…

    The G word: How to get your audio off the ground (Part 3)
    https://www.edn.com/the-g-word-how-to-get-your-audio-off-the-ground-part-3/

    Reply

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