An XLR Cable is Just a Cable, Right?

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The discovery of electricity has dramatically changed our lives, with the wonders of modern science surrounding us everywhere—the light bulb, the electric motor, radio waves. Who would want to be without them? Audio engineers, for one, because all of the above are potential sources of audio pollution that can affect our pristine signal, as it travels between source and destination. Refrigerator motors, light dimmers, radio transmitters, Wi-Fi, etc., can all cause unwanted noise in audio. Of course, the proposition is absurd, since without electricity there wouldn’t be audio engineers and cables, to begin with. However, the point is that what benefits us one way can easily be detrimental in another situation.

There are multiple points at which a signal can degrade in an audio system, but often the first culprit is a microphone cable. Why the microphone cable? What’s the big deal? Attach a microphone to one end and plug the other end into a preamp and you have sound, right? Yes, except that the cheap cable you just bought at the discount store is providing your vocal with an accompaniment featuring a local taxi dispatcher’s instructions, along with some nice 60-cycle hum. Might be what you want if you’re into avant-garde recording, but otherwise those are some serious problems. You run out to the local music store and buy a really expensive cable and suddenly all of those issues are gone—or perhaps not. So, did you spend your money wisely?

Despite cables being ubiquitous, information that helps the typical purchaser make competent decisions about a cable’s performance is hard to come by. Mostly, manufacturers tend to rely on marketing rather than hard facts to promote their cables. Low noise, oxygen-free copper, and gold-plated contacts are all notable features, but they don’t really tell you why a given feature will work, or in what scenario. And sometimes, unfortunately, the manufacturer misstates facts that only confuse. This article aims to dispel the hype, while examining what constitutes a good, balanced microphone cable.

A balanced microphone cable consists of three main components—the conductors (internal wires, or cores), which carry the signal; the shielding, which helps protect the integrity of the information passing through the conductors; and in the case of a microphone cable, three-pronged connectors (XLR) that allow connection of the cable at either end. All three need to work together to ensure proper functioning of the cable, especially with increased lengths, as distance provides additional opportunity to increase electromagnetic and other noise interference.

So, what is it in particular that makes a microphone cable susceptible to noise interference? Microphones generally operate at very low voltages, with the output requiring a relatively hefty amount of amplification applied to it before the signal can successfully travel on its way through an audio system, at line level. When the signal arrives at the preamp, any noise that has infiltrated the cable becomes greatly amplified along with the original signal. Using a good, balanced cable helps to eliminate the problem.

The solution starts with the signal generated by the microphone capsule being sent over two wires, with one side inverted by 180 degrees. A differential input amplifier at the receiving end re-inverts and then combines the two signals. Since any interference entering the cable during transmission will appear equally in both conductors, the induced noise is now inverted and therefore cancelled (phased) out, leaving the original signal intact. Additionally, the original signal is slightly strengthened by the recombination of the two sides, thus helping to compensate for any reduction in signal strength that occurs on a long cable run. However, it should be noted that any noise inherent in the signal, from say, a noisy microphone, will not benefit from this process.

Having defined the basic operation of a balanced cable, let’s look in detail at each component. Although it is not customary to give away the plot, let me state that the shield is the most important factor in a cable. But it makes sense to start the discussion from inside out, so let’s begin with the conductor, the part that carries the audio signal. Copper has been the material of choice for conductors for well over a century, because it has the greatest electrical conductivity of all non-precious metals. Normally, the stronger a metal is, the less pliable. Copper is unique in that it combines strength with high pliability. It is resistant to the effects of corrosion, which normally weaken other metals and impair their conductivity, and copper is easy to solder, allowing for durable connections.

Generic Balanced Cable

The use of oxygen-free copper in cables is contentious. There are “levels” of oxygen-free copper, with 99.99% OFC (Oxygen Free Copper) being the purest form. Certain audiophiles insist their cabling meets this highest standard of purity. However, in reality the difference between the grades is negligible for most audio applications. The purest copper is required only for extreme scientific situations such as the manufacture of semiconductors, or for use in particle accelerators, etc. Use of such copper in audio is expensive and unnecessary. For audio applications OF (Oxygen Free) and the most common ETP (Electrolytic-Tough-Pitch) copper will meet the needs of audio applications.

Audio cables generally use a stranded conductor as opposed to a solid cable. While the latter is cheaper to produce, a solid conductor is more rigid and prone to breaking when flexed. Obviously, microphone cables need flexibility, and a stranded conductor provides that. And if damage to a strand does occur, the whole conductor does not cease functioning. Also, in certain circumstances the stranded conductor can include a higher “volume” of copper than a solid one, aiding in the transmission of the signal. The downside is that termination of the stranded conductor is slightly more finicky, and if the strands aren’t wound tightly enough, the conductor will have a higher resistance, which in turn will require greater electrical energy to maintain the same flow.

As noted, a balanced cable needs at least two conductors (cores), with the majority of cables belonging to this category. Generally, the cores vary in thickness between 26- and 20-AWG (American Wire Gauge), with the smaller number being thicker in diameter. Here, the compromise is between a manageable overall thickness of the cable, as applied to its flexibility and level of conductivity. Some cables feature four cores (two pairs) and are often referred to as quad cables. Four-core cables are more expensive, but in extremely “noisy” environments or where cables run unavoidably parallel to power cables, they can provide at least 20 dB or more of common-mode noise reduction when compared to two-core cables. However, care should be exercised as not all these cables are constructed equally, with some cheaper varieties simply having four parallel cores wrapped in the cable jacket, which can introduce more problems than they solve. To be effective, the four cores need to be wound tightly around each other to achieve the additional noise cancellation that such a configuration provides.


Four Core Cable

Now let’s look at cable shielding. This is where a cable will stand up or fall down. You can have all the OF copper you want, with millions of strands, but if the signal traveling down the cable is compromised with noise, then it is next to useless. To this end, there are multiple layers of protection that address the basic forms of electrical interference, and we will discuss those as we travel through the various layers of a complete cable. It should be noted that not all cables have the same kinds and levels of protection, and most of that comes down to price.

The first order of things is to isolate the two (or four) cores from each other, and not just for the obvious reason that wires that touch will short each other out. Any current travelling down a wire will generate a magnetic field, and the resulting EMI (Electromagnetic Interference) introduces noise in an adjacent conductor. In this case a layer of insulation is applied over each core to contain the magnetic field. These days, polyethylene (PE) is used, since it provides better insulation over the PVC found in earlier cables. Although not a 100% insulator, the voltage levels present in an audio cable are small enough that they will not overwhelm the insulator. Some cables then add a layer of conductive (modified) PVC on top to do the opposite, that is drain off any EMI that might be trying to enter the conductors from outside.

The other form of protection that is common to all cables is a metal-based shield, usually copper but sometimes TAC (Tin Plated Copper), and in the case of foil, an aluminum laminate. This is the third leg of a balanced cable, and is connected to ground via the third pin of the XLR connector. A foil shield provides excellent coverage and is very effective when radio frequency (RF) interference is present. It is also lighter and cheaper to produce, but the down side is that it is far easier to damage when flexed, is more difficult to terminate, and should only be used in fixed installations, or as an absolute last resort.

Copper Braid TAC Braid

The other type of shield is a braid, an interwoven mesh of bare or tinned copper wires, which is much easier to terminate. TAC braiding is more expensive than regular copper, but the tin coating aids in preventing oxidation of the copper and improves wear. The type of braiding also comes into play. Because copper possesses higher conductivity than aluminum and the braid has a larger mass, it is more effective as a shield. It doesn’t provide absolute coverage due to the unavoidable presence of small gaps in the braid, but given that for stationary cable 70% coverage will usually suffice, the 98% offered by the braid is more than sufficient. However, it will add bulk and cost to a cable.

Copper Spiral Braid

A spiral shield utilizes helical, wrapped strands for up to 97% coverage and provides excellent flexibility, but gaps in the weave can open up when the cable is flexed. Some manufacturers implement dual-spiral shielding where each core gets its own shield. This provides better cable flexibility while ensuring the integrity of the shield. For very noisy environments, combination shields consisting of more than one layer of shielding are employed. For broadcast and studio applications, a braided shield with conductive PVC is the best solution, whereas where flexibility is required, as in live-sound situations, dual-spiral with conductive PVC is the preferred answer.

Dual Copper Spiral Braid

Another issue is the presence of microphonic noise. This has nothing to do with the microphone, but is noise generated within the cable when it is flexed. A poorly designed or damaged cable allows friction to be created between the two conductive cores, resulting in static discharges which in turn are amplified by the high gain of a microphone preamp. To prevent such movement, cotton yarn is placed between the insulated conductors and the braid. Finally, the outer jacket has no effect in regard to noise, and while a heavier one will help protect the cable innards in high-traffic areas, heavier doesn’t necessarily mean better. It’s all a question of application.

The issue of frequency-response degradation in cables is sometimes brought up, and while there is a small potential for a cable to do this, the problem is largely immaterial except when dealing with extremely long cable lengths. It takes close to four hundred feet of cable to produce 1 dB of attenuation at 20 kHz (nominal), which in most live situations, is virtually inaudible.

And so we come to the connectors. XLR connectors are favored for two reasons. The first is the design of the female XLR connectors, which allows pin 1 (the earth pin) to connect before the other two pins, (which carry the signal) when the male XLR connector is inserted. With the ground established first, it is possible to insert or remove the connectors, especially in live-equipment situations, without picking up external signals. (TRS phone connectors mate the ground last, which can cause short bursts of hum, or cracks and pops.) The second advantage of the XLR connector is the external locking mechanism on the female connector that provides an additional level of security.

There are several different types of XLR connectors and methods of termination. Due to its modular design, the internal, four-part cable connector as developed by Neutrik allows for field serviceability in the event of a cold solder joint or other damage around the area of the connector. This design is also used on connectors from Rean and Attaché. Manufacturers of other types of XLR plugs include Switchcraft and Amphenol, along with various Far East companies that produce unbranded plugs. Molded connectors, (those that are permanently affixed to the cable ends) while cheaper, will involve greater cost down the road, if the wiring inside the connectors fails and the cable needs to be completely replaced.

Modular XLR Female Connector

Another question often asked is: which are better, gold- or silver-plated contacts? Gold is not as good as a conductor as silver but has a greater level of corrosion resistance, and many people prefer the look of the gold-plated connector. But unless the cables are to be used in harsh environments (close to sea water for example) the added cost is mostly unwarranted. Other considerations for a good XLR connector are what kind of chuck-type strain relief is provided, and the quality of the boot that covers the connector points to alleviate bending stress. The internal thread on the shell should be protected from damage, and some cable manufacturers include shrink-wrapped solder points for added protection and to meet broadcast specifications.

Neutrik Connector (Exploded View)

The “XX” connector from Neutrik is a redesign of the company’s older “X” design, generally considered the best, but more expensive choice for premium cables. It employs a strengthened grounding spring on the female connector for a more robust ground connection, while the female receiving sockets offer more points of contact with the male pins (eight points versus three), and a tighter tolerance of the pins and sockets for improved connectivity.

Neutrik "X" Connector Neutrik "XX" Connector

In summation, the following points need to be considered. Use a cable that is suited to the application. In environments with high EMI and RFI (these days that could be almost anywhere, with the proliferation of wireless communications), a braid/conductive PVC combination should be considered. If the cable will be subjected to repeat flexing, a spiral shield might offer better performance than a braided shield. Again, foil shielding should be avoided since continuous flexing will damage the foil. Make sure the connector provides as effective shielding as the cable itself, and make sure that the equipment being connected is properly matched. A too-high output from a preamp can overdrive and distort a down-stream circuit, while a low-level signal will not make use of the full dynamic range of the complete system. Following this advice will ensure clean and problem-free audio.

Comparison Chart
  Cores- Twisted Gauge OFC %Shield Type  Material Conductive PVC Shield Shrink Wrapped Solder Connector Contact Material Connector Color Cable Color
Audio-Technica
AT8314 Premium Microphone Cable 2-Yes 24 AWG No 100% Dual Spiral Copper Yes No Neutrik XX Nickel Silver Black Black
AT8313 Value Microphone Cable 2-No 24 AWG No ns  Spiral Copper No No OEM - similar to Neutrik X Nickel Silver Silver Black
Blue
Dual  Cable 2-Yes 22 AWG No 95% Braid TAC No Yes OEM - similar to
Neutrik X
Nickel Silver Silver Blue
Quad Cable 4-Yes 22 AWG No 95% Braid TAC No Yes OEM - similar to Neutrik X Nickel Silver Silver Blue
Canare
Star-Quad (L-4E6S) Microphone Cable 4-Yes 24 AWG No 95% Braid TAC No No Neutrik XX Gold Black Black, Blue, Brown, Grey, Green, Orange, Purple, Red, White, Yellow
Comprehensive
Performer Series Microphone Cable 2-Yes 24 AWG No 90% Braid Copper No No Neutrik XX Nickel Silver Black Black
Touring Series Microphone Cable 2-Yes 20 AWG No 95% Braid Copper No No Neutrik X Gold Black Black
Studio Series Quad Audio Cable (L-4E6S) 4-Yes 21 AWG No 95% Braid TAC No No Neutrik XX Gold Black Black, Blue, Brown, Grey, Green, Orange, Purple, Red, White, Yellow
Hosa Technology
Hosa Contractor Series Microphone Cable (CMK-) 2-Yes 20 AWG Yes 95% Braid Copper No No Neutrik XX Gold Black Black
Hosa Quad Microphone Cable (CMI-) 4-Yes (not tight ) 24 AWG Yes 90% Braid Copper No No OEM - similar to Switchcaft AA Nickel Silver Silver Black
Hosa Standard Microphone Cable (MCL-) 2-Yes 22 AWG Yes 88% Braid Copper No No OEM - similar to Switchcaft AA Nickel Silver Silver Black
Hosa Economy Microphone Cable (MBL-) 2-Yes 24 AWG Yes 76% Braid Copper No No OEM - similar to Switchcaft AA Nickel Silver Black Black
Hosa Pro Microphone Cable (HMIC-) 2-Yes 20 AWG Yes 90% Braid Copper No Yes Rean Nickel Silver Black Black
Hosa Elite Elite Microphone Cable (EMIC-) 2-Yes 20 AWG Yes 95% Braid Copper Yes No Neutrik XX Gold Black Black
Kopul
Studio Elite 4000 Series Microphone Cable 2-Yes 24 AWG Yes 98% Braid Copper Yes Yes Neutrik XX Silver Plate Black Black
Performance 2000 Series  Microphone Cable 2-Yes 24 AWG Yes 92%   Dual Spiral Copper Yes No Attache Silver Plate Black Black
Premium Performance 3000 Series Microphone Cable 2-Yes 24 AWG Yes 95%   Dual Spiral Copper Yes Yes Neutrik XX Silver Plate Black Black
Premier Quad Pro 5000 Series Microphone Cable 4-Yes 24 AWG Yes 99% Braid TAC No Yes Neutrik XX Gold Black Black
Mogami
Gold Studio Microphone Cable 4-Yes 24 AWG Yes 100% Spiral Copper No No Neutrik X Gold Black Black
Gold Stage Microphone Cable 4-Yes 24 AWG Yes 95% Braid Copper No No Neutrik X Gold Black Black, Red, Yellow,
Green, Blue
Monster Cable
Performer 500 Series Microphone Cable 2-Yes 20 AWG No 95% Braid Copper Yes No Neutrik Molded Gold Black Black
Standard 100 Series Microphone Cable 2-Yes 22 AWG No 92% Braid Copper No No Molded Nickel Silver Black Black
Pearstone
PM Series Microphone Cable 2-Yes 24 AWG Yes ns  Spiral Copper Yes No Attache Silver Plate Black Black
SM Series Microphone Cable 2-Yes 24 AWG Yes ns  Spiral Copper Yes No Molded Nickel Silver Silver Black
Pro Co Sound
MasterMIKE Microphone Cable 2-Yes 23 AWG No 94% Braid Copper No No Neutrik XX Nickel Silver Black Black
Ameriquad Microphone Cable 4-Yes 24 AWG No 95% Braid Coppper No No Neutrik XX Gold Black Black
Excellines Microphone Cable 2-Yes 24 AWG No 90% Spiral Copper No No Neutrik XX Nickel Silver Silver Black
StageMASTER Microphone Cable 2-No 24 AWG No 72%   Dual Spiral Copper No No Rean Molded Nickel Silver Silver Black
Remote Audio
Quad Microphone Cable (L-4E6S) 4-Yes 24 AWG No 95% Braid TAC No No Neutrik XX Nickel Silver Black Black
Shure
Triple-Flex Microphone Cable 2-Yes 26 AWG No ns  Dual Spiral Copper No No OEM - similar to Switchcaft AA Nickel Silver Silver Black
Hi-Flex Microphone Cable 2-No 26 AWG No ns  Spiral Copper No No OEM - similar to Switchcaft AA Nickel Silver Silver Black
Whirlwind
MK Series (Accusonic+2) Microphone Cable 2-Yes 22 AWG No 78% Braid Copper No No Whirlwind Gold Black Black
Quad (MKQ) Microphone Cable (L-4E6S) 4-Yes 24 AWG No 95% Braid TAC No No Whirlwind Gold Black Black, Red, Yellow, Green, Blue, Grey

Cable Glossary
Amplifier  Electronic component or circuit for amplifying power, current, or voltage. In this context, a pre-amplifier takes microphone level signals and boosts them to line level.
Balanced Equal distribution of weight, amount, etc. A balanced cable refers to the signal being sent across two conductors, with the phase of one side reversed.
Boot  Sheath-like protective covering. Some XLR connectors include a boot that slides over the internal connectors of the plug to provide additional protection.
Braided Shield Multiple strands of material interwoven to form a shield to protect against radio interference.
Cable Insulated electrical conductor, often in strands, or a combination of electrical conductors insulated from one another that transmits electrical information.
Capacitance Ability of a body to store an electrical charge and eventually discharge it.
Capsule Part of the microphone that responds to incoming sound-pressure waves and in turn outputs a corresponding voltage that is sent along the cable to a preamplifier.
Chuck Device for centering and clamping an object. In this case, the cable where it enters the connector.
Common-Mode Rejection Ratio (CMRR) A number that describes how well an input or output will reject noise, or how well "balanced" a balanced line is. A high CMRR is important in applications where the signal is represented by a small voltage fluctuation, as in microphone signal transmission over balanced lines.
Conductor Substance, body, or device that readily conducts heat, electricity, sound. Refers to the cores contained in a cable.
Connector Device for connecting one object to another. In this application, types include XLR female or male.
Copper Malleable metallic element used in large quantities as an electrical conductor.
Core Innermost part of a cable, also referred to as conductor.
Corrosion Process in which a metal is changed by a chemical reaction, causing it to lose conductivity. Copper is relatively good at resisting corrosion, but even when it corrodes, the overall conductivity of the metal is not greatly reduced.
Differential Input Amplifier Type of electronic amplifier that amplifies the difference between two voltages but does not amplify the particular voltages.
Electrolytic-Tough-Pitch (ETP) Standard type of commercial wrought copper used in the production of electrical wire.
Electromagnetic Interference (EMI) High or radio-frequency disturbance that affects an electrical circuit, due to either electromagnetic induction or electromagnetic radiation emitted from an external source, such as light dimmers or refrigerator motors.
Impedance Description of a circuit’s resistance to a signal, as measured in ohms, thousands of ohms (Kilohms), or millions of ohms (megohms).
Line Level  Refers to the voltages used by audio devices such as mixers, signal processors, tape recorders, and DAWs.
Magnetic Field Mathematical description of the magnetic influence of electric currents and magnetic materials. Produced by electric currents in wires.
Microphone Level Very low level signal output from microphones, typically around 2 millivolts (2 thousandths of a volt).
Microphonic Noise Phenomenon in which certain components in electronic devices transform mechanical vibrations into an undesirable electrical signal (noise).
Microphone Preamp An electronic device used to amplify low-level signals. Commonly used to bring microphone outputs up to levels that subsequent equipment can utilize, such as mixing consoles, tape recorders, or Digital Audio Workstations (DAW).
Ohm Unit of electrical resistance. Named after its founder Georg Ohm, Ohm's Law states that current varies in direct ratio to the wires' resistance.
Oxygen-Free Copper Copper that has varying degrees of oxygen removed to increase its purity.
Polyethylene (PE) Synthetic plastc material used in multiple applications, including electrical cable insulation.
PVC Synthetic plastc material also used for electrical cable insulation.

Quad

Generic term for balanced cables that use four conductors

Radio Frequency (RF) Interference from signals that are in the radio frequency range.
Resistance The opposition that a substance offers to the flow of electric current. All electrical systems display a certain amount of resistance. The standard unit of resistance is the ohm.
Shielding Various methods for preventing inteference entering a system.
Tin-Plated Copper (TAC) Widely used in the electronics industry because of its ability to protect the copper from oxidation and preserve its solderability.
XLR Standard three-pin connector on which pin 1 is typically connected to the shield of the cabling to provide a ground, whereas pins 2 and 3 carry the actual audio signal, normally in a balanced (out-of-phase) configuration.

143 Comments

Fantastic article! Very informative, clear, and easy to read. 
I didn't read all the comments, but I did search for 'patch', and couldn't find the answer to the questions that brought me here...
I'm planning on making my own patch cords. All the ones I've seen so far are made of a 1-conductor shielded cable terminated with TS connectors. But can I use microphone (balanced) cable and TRS connectors for that? And, apart from the additional cost and work, what would be the downsides?
 

Hi - 

No down side.  But if I am understanding you correctly, we have these balanced (patch) cables already fabricated for you:

The 10' Balanced 1/4" TRS Male to 1/4" TRS Male Audio Cable from Hosa Technology is a professional audio cable that is ideal for touring and live sound applications where 2 devices with balanced 1/4" jacks need to be connected together. The cable has nickel-plated REAN connectors for excellent durability and efficient signal transfer.

The conductors are made from 24 AWG oxygen-free copper to maintain a clear signal path. The cable also has 90% OFC spiral shielding for terrific flexibility and effective EMI and RFI rejection. The cable is 10' long and has a 1/4" TRS male phone connector at each end.

Ideal for professional touring and live sound applications where 2 devices with balanced 1/4" jacks need to be connected together
The nickel-plated REAN connectors provide excellent durability and efficient signal transfer
The conductors are made from 24 AWG oxygen-free copper to maintain a clear signal path
90% OFC spiral shielding provides terrific flexibility and effective EMI and RFI rejection
The cable is 10' long and has a 1/4" TRS male phone connector at each end
 
Hosa Technology Balanced 1/4" TRS Male to 1/4" TRS Male Audio Cable (10') 
B&H # HOHSS010
https://bhpho.to/2rmf6Dx

Also available in a variety of shorter and longer lengths

The explanation about why microphone cables are so susceptible to noise is clear and concise.

However the explanation of how phase inversion cancels out interference is not as clear.

"Since any interference entering the cable during transmission will appear equally in both conductors, the induced noise is now inverted and therefore cancelled (phased) out, leaving the original signal intact."

What does "appear equally" mean? Or rather, why is that necessarily the case?

Could not interference affect only the hot wire and not neutral, or vice versa or both? If not, why not?

And if interference appears in both equally, could the interference not also be inverted on the neutral side and not on the hot side? If not, why not?

I'm not clear on how exactly the noise is cancelled, and when exactly that occurs.

It’s been a month since you asked your question and I don’t know if you have found an answer yet but I’ll make an attempt to explain exactly what is going on here.  First the microphone is sending two signals down 2 separate wires in the XLR cable. The two signals are 180 degrees out of phase with one another.  If they were to arrive at this state at the receiver/amplifier, the two signals would cancel each other out when combined together. This is because the phasing places the peak of the signal in wire #1 at exactly the same point in time as the valley in the signal in the other wire. Combining the two in this out of phase star results in a flat line rather than a wave so there would be no audio delivered to the amplifier is we left it this way.  Remember this concept because when we fix things to make the audio come to life, this is what is going to kill the noise. 

You asked what was meant by the noise being delivered equally to both wires, and how we know this to be the case and how we know that the noise is not out of phase between the two wires.   First, the two wires are acting like two antennas in close proximity to one another do, they are going to pick up the same signals from the same sources.  The peaks and valleys of the waveforms are going to be perfectly aligned with each other and that is what is meant by appearing equally in both wires. As far as how we know that the noise is not out of phase in each wire already, well, if that were happening at the source it would never reach our wire in the first place, because the two wave forms would cancel each other out right there at the source.  It is frankly impossible for to out of phase signals to travel together in this way  

So at the point just before our signals get to the receiver, we have a waveform in the first wire that has our audio, and we have another waveform that has our noise. In the second wire, we have a waveform of audio that is 180 degrees OUT of phase with the audio in wire #1 and a waveform of noise that is IN phase with the noise waveform in wire #1.  Next is when the magic occurs.  As the signals enter the receiver, BOTH signals are inverted 180 degrees in wire #2 ONLY!  This brings the 2 audio signals back into phase with each other so that they are amplified and now the noise signals are 180 degrees out of phase with each other so that they cancel each other out. Pretty slick, huh?

Hope This helps.  

Hello, is there an article about the best instrument cables?  Thanks

Hi Alessio -

Check out these instrument cable articles in our Explora on-line library:

Get Connected with Kopul Premium Quarter-Inch Instrument and Patch Cables

You Only Sound as Good as Your Weakest Link: The Value of RoadHog Cables

quick question: say you're using a very thin mic cable, such as a DPA 4060 - https://www.bhphotovideo.com/c/search?Ntt=dpa%204060

I've heard reports of it picking up EM interference from cell phones and the like at venues. Would it make sense to wrap this in a braided sleeve to reduce this, and would that then have to be grounded somehow?

Hi Andrew - 

We have not encountered this issue with DPA products. The quality and engineering of their cables are the stuff of legend.

I haven't encountered it either - just heard some people say that it might be an issue, and wanted to be proactive. But I'll wait until I hear a problem before diving into this. Thanks!

On the whole a good article, however while the item about balanced audio cables correctly refers to their superior immunity to interference, the explanation as to how this is achieved is misleading. The reason it works is that the audio signal is the voltage difference between the two conductors. As you describe the interference is induced onto both conductors in phase, which results in no voltage difference between the conductors. The audio signal is not flipped as you describe it in the article; the cable has to be connected to a balanced input amplifier or an audio transformer. It is the amplifier or transformer that uses the voltage difference between the conductors, and rejects the in phase, or common mode, interferance. Hence the term Common Mode Rejection or CMR, CMCRR or Common Mode Rejection Ratio being a measure of how well an amplifer performs this.

Also the article makes no mention of Quad cable; this has even more immunity to interference than normal balanced cable. The source of the interference will effectively be a point source, thus one of the conductors in the cable will be slightly closer to the source, and thus will have very slightly more interference induced into it. Quad has 4 cores wrapped together, opposite pairs are joined together at each end to form a single conductor, the result being that the amount of interference induced into each pair is more closely matched, thus greater immunity. It's much easier to explain using a diagram

There's no difference between what the article says and what your first paragraph says. The article says that the signal is flipped and added. Your paragraph says that the difference is used.

But these two are equivalent so both explanations are equally correct.

Flipping the signal is the same as multiplying it by -1.

So the article says that  X + Y*-1 is used, while your comment says that X-Y is used.

But these are just two different ways of saying precisely the same thing.

Hey Mark and Jurek :) I enjoyed the article throughly. 

My question is somewhat more of an interest than anything else. I personally am a Kopul fan, but I am courious to know what are your personal favorites?

Much thanks!

Chris F.

I'm looking for a high quality cable to connect my Rode Procaster to my Focusrite Scarlett 2i2. Any suggestions?

Should have added this will be for podcasting and YuoTube videos predominantly 

Hi Dan - 

The Kopul Premier Quad Pro 5000 Series XLR M to XLR F Microphone Cable - 6' (1.8 m) is a studio- and broadcast-quality 4-conductor cable precision engineered for maximum rejection of RFI and electro-magnetic interference, extremely quiet performance, high flexibility and durability. Its twisted quad-conductor design features oxygen-free copper and allows for excellent conductivity, flexibility, low capacitance, and tensile strength.

This design affords the conductors a twist pitch length of only 2cm, reducing interference by assuring the minimum amount of the conductor is parallel to interference sources at any given section. The result is increased rejection of electro-magnetic and RFI noise, even in close proximity to the source. Cotton yarn is packed in to reduce friction between conductors and prevent unwanted electrostatic build-up and microphonic noise. The 99% braided TAC shield provides additional noise protection and corrosion resistance. Its Neutrik XX gold connectors provide high-quality, corrosion-free connectivity, and each solder point is individually shrink-wrapped for additional protection and to meet network broadcast facility standards.

Premier Quad Pro 5000 Series cables are ideal for use in the most demanding studio, touring, and broadcast applications.

Hi Dan - 

The Kopul Premier Quad Pro 5000 Series XLR M to XLR F Microphone Cable - 6' (1.8 m) is a studio- and broadcast-quality 4-conductor cable precision engineered for maximum rejection of RFI and electro-magnetic interference, extremely quiet performance, high flexibility and durability. Its twisted quad-conductor design features oxygen-free copper and allows for excellent conductivity, flexibility, low capacitance, and tensile strength.

This design affords the conductors a twist pitch length of only 2cm, reducing interference by assuring the minimum amount of the conductor is parallel to interference sources at any given section. The result is increased rejection of electro-magnetic and RFI noise, even in close proximity to the source. Cotton yarn is packed in to reduce friction between conductors and prevent unwanted electrostatic build-up and microphonic noise. The 99% braided TAC shield provides additional noise protection and corrosion resistance. Its Neutrik XX gold connectors provide high-quality, corrosion-free connectivity, and each solder point is individually shrink-wrapped for additional protection and to meet network broadcast facility standards.

Premier Quad Pro 5000 Series cables are ideal for use in the most demanding studio, touring, and broadcast applications.

  I am trying to connect a Shaker Retro Rocket harmonica mic that takes a cable with a female XLR to a small guitar amp with a 1/4 inch connector. A Rapco brand high impedance cable with xlr to 1/4" with pin 2 hot has been recommended. I am not really sure what "pin 2 hot" means but the Rapco is the only one that specifies that specifically. The reviews on this cable have not been all that good from a reliability/durability standpoint.  Could you recommend any other brand that would carry this cable

Hi Frank - 

I am sorry - but we do not offer a guitar or microphone  cable in this configuration.  And does the guitar amp have a microphone input?  Even dynamic harmonica microphones are not designed to deliver the same impedance as guitars.  

Please contact us via e-mail if you have additional questions:

Generally informative article but I have to suggest that the following extract from the article is nonsense:

" In this case a layer of insulation is applied over each core to contain the magnetic field. These days, polyethylene (PE) is used, since it provides better insulation over the PVC found in earlier cables. "

A PE (or PVC) insulating layer is not going to stop magnetic (H-field) radiation. (Life would be a lot easier if it could :-)

Mag field radiation attenuation relies mainly on the twisting of the conductors (assuming twin core screened cable) such that the magnetic component from each conductor cancels the other to some extent (tighter twists = better) and the Common Mode Rejection of the receiving circuit.

An overall screen will do little to help Mag field radiation from the cable as a whole as it would need to be ferrous (ideally 'mu-metal') or really thick. This means expensive and/or not practicable.

Looking for 3 foot xlr cable for my multiple mic deck to mixer. 

I have noticed some have horrible interferance or make the voice  grainy.

what xlr cables would you recommend?

Hi Cat - 

The Canare Star Quad (L-4E6S) Microphone Cable 3' (0.91 m) is the premier Star Quad cable for all handheld microphone applications. This cable uses trusted Canare technology to give you the optimum in sound quality. Flexible, satin smooth to the touch and extra strong, this standard diameter, 21 AWG cable fits perfectly in all XLR-type audio connectors. Forty separate strands in each conductor eliminate breakage due to flexing. A cross-section of the cable shows four conductors arranged as two pairs in an "X" configuration. The result is a microphone cable that resists induced noise in the most severe environments.

Greetings! Happy to see your website.Yesterday I got so frustrated trying to make my mic work. I just bought an AT2020 XLR Mic and my XLR cable that works with my cheap recording mic does not work with my AT2020 even when plugged to my interface. If I invest on a Neutrik XX will my AT2020 finally work?

Hi Agnes - 

Certainly a bad cable could be causing the issue.  You may want to check your host device's XLR input as well with a different microphone.  Remember that this microphone requires 48 volts of phantom power to operate properly.  Check your host device to make sure that phantom power is available and switched on.

An excellent description of more than I ever knew about XLR wiring! However, I cannot find anywhere on the internet anything about wiring anti phase - can you help me please?

I need to make leads (XLRs both ends) to bridge my HIFI amps to mono, and am assured they must be wired antiphase. They will be from a single male XLR plug at the preamp end, wired to two cables terminated in male XLRs to go into the two channels of one power amp. And obviously another similar "Y" cable for the other channel and amplifier 2. 

If they have to be wired antiphase, which wire goes to which terminal? Any help would be deeply appreciated.

Hi David - 

You are most likely referring to reverse polarity or out-of-phase.  I'm sorry, but we cannot advise you regarding out-of phase wiring.  Please contact your amplifier and or speaker manufacturer before attempting this procedure.

Thank you for all the information.  I have a few questions.  I plan on recording with an audio-technica AT831b microphone, plugged into a Tascam recorder DR-40 version 2, Linear PCM recorder.  There are multiple EM field issues in the room I will be recording.  I will be filming at the same time on a camcorder, and using work lights I bought at the Home Depot.  Plus, there is a TV in the room, Wi-Fi in the house, etc.  (My previous attempts to film w/ lavalier mics that plugged into the camcorder were way too noisy, so now I'm going to try recording the sound on a seperate device & hire someone to take the sound off the video recording & sync the audio from the seperate device onto the video.)

How far away from the lights & camcorder does the microphone cable need to be?  Is is worth it to try to unplug the TV or turn off the WiFi?  In another blog I saw mention of wrapping the cable on an RFI choke.  What is that?  Would it help?

My back-up microphone is a MOVO USB M-1 that plugs into my MacBook Pro.  That has more background noise than the other set-up though.

I am grateful for any insight you can provide.

Kim

Hi Kim - 

There is no hard number one can provide for EMF range and the issues it causes with sensitive electronics.  Same room, within 20 to 30 feet will almost always be problematic. Using lighting designed for industrial or home shop applications is obviously not a recommended practice.  The purchase of studio designed lighting is worth the investment.  Turn off all Wi-Fi, cell phones, televisions and any  other unnecessary electronics or appliances.  There may be AC line interference operating here as well.  If possible, route your recording devices to a different electrical circuit entirely.  I would not start investing in filters or chokes at this point.  Best to obtain the proper lighting components.

Great read. I gather that the best solution is to simply make your own cables. It would be cool if you posted some links to a trusted source where you can get a quad tight wrap and every thing else you mentioned. I would love to make one beast of a cable and compare it to the others I have gone through. 

Great article, more than I ever knew, and I've used XLR cables on and off since 1967.

Our contractor recently installed additional mic cabling in our church stage.  The new male XLR connectors appearing in the control room are too noisy!  Each one makes crackling and 60Hz hum if I move them a bit while plugged in.  (Our older male XLR connectors are tortally quiet when used on the same mixer.)  I cannot identify the brand, but I'm asking the contractor to come back with better hardware.  (There are only 4 lines involved.)

Hi, i am trying to connect my shure beta 87c to my laptop but it isnt working. All that is happenning is the microphone doubles up as a speaker which doesnt make sense to me. I was wondering if the problem could be the cables. Should i get an xlr to usb cable because i am using a jack pin and it doesnt seem to be functional. Please help

HI Count - 

You will need a USB interface to connect a Shure beta 87c to your laptop:

The Second-Generation Scarlett Solo from Focusrite is a portable USB 2.0 digital audio interface, featuring a single Scarlett microphone preamp with phantom power, and a dedicated instrument/line input. You can monitor your signal either through an independent 1/4" output or via rear-mounted, unbalanced RCA jacks. Perfect for the travelling troubadour, this unit is fully compatible with Mac and Windows computers, and includes a plethora of recording, instrument, and sample content software.

Notable Features

  • One Scarlett mic preamp with high headroom and minimal distortion (provides 48V Phantom Power)
  • One line/instrument input, designed to handle high-level pick-ups
  • Conversion and sample rates up to 24-bit/192 kHz  
  • Low latency for using your plug-ins in real time without the need for DSP
  • One headphone output with gain control
  • Stereo RCA outputs for connecting to home speakers
  • Compact and portable at 1.3 lb
  • Powered by USB
  • Includes Pro Tools | First Focusrite Creative Pack and Ableton Live Lite
  • Includes additional software and loops

Do I need a special jack on my guitar to use xlr cables?

Hi Lorenzo -

Guitars will use a 1/4"  female phone output:

The 25' Studio Elite 4000B Series 1/4" Male Right-Angle to 1/4" Male Studio Instrument Cable with Braided Mesh Jacket from Kopul is designed for connecting guitars to amplifiers or any other application where a 1/4" instrument or unbalanced line-level connection is required. It can be used in several studio environments for applications such as recordings, broadcast TV, post production houses, and more.

I think an important information is missing and it's how the outer jacket affects the flexibility of the cable and what is the difference between various jacket materials when it comes to that.

Hi, great article!!!

What are your thoughts on "Ferrite Core Cord Ring RFI EMI Noise Filter Cable Clip"?

Would they help in reducing the noise as well even if you have a cable with a tightly braided screen?

Kind regards;

Hi Douglas - 

These ferrite core rings can be effective only on a cable carrying a digital data signal like a USB cable.  An XLR cable is carying an analog signal and any interference that can be filtered is likely to be created by power.  In that case choose a power conditioner for your AC outlet. 

Hi Mark;

Thanks for the prompt response.

My question has to do with Cable Mountain Stereo Jack to 2x RCA Phono Plug; I also saw other sound cables with them on, hence the question.

Kind regards;

Hi Douglas - 

My answer is still germain.  B&H does not offer this product so we have never actually auditioned them. You may want to check with one of their UK re-sellers.

I have a Shure 57 Microphone that I want to re-cable.  Currently it has a 4-pin XLR to a 1/4 jack for live use.

I would Like to be able to hook it up to my Focusrite 2i2 Digital Interface and then use it in Logic Pro X.

My question to you is.... The XLR that is currently hooked into the Shure 57 is a (4-Pin XLR Male).   How do I wire the (3-Pin Male XLR) so it works correctly with my Focusrite 2i2?  (4 post to 3 post)

Thank You!

Hi  Rich - 

Use the schematic in the User's Guide and the information below to rewire.  You may also want to check with Shure as well; 

XLR pin 1 = shield

XLR pin 2 = low impedance audio hot
XLR pin 3 = low impedance audio return

Thanks for your reply Mark! Rich

Mark... Shure just said that they no longer support Ampernol and know nothing about it....... Rich

Hi Mark..... I think I have the correct jack to finally change out my 1/4" jack to an XLR.... Please see what I want to do below....

•  4- pin Amphenol Jack: 1. Twisted Sheild  2. Red wire  3. Black Wire   4. Clear or White wire

•  3-pin XLR Jack:  (Ground,   1,   2,   3,)  MY QUESTION: with the info above.....What colors go to the XLR posts?

• To me it looks like you would put the Twisted Shield to the ground, Post 2 RED, Post 3 BLACK,  and Post 1 Clear.White???

Let me know will ya?  Thanks again Rich Leffler

<I have a Shure 57 Microphone that I want to re-cable.  Currently it has a 4-pin XLR to a 1/4 jack for live use.

I would Like to be able to hook it up to my Focusrite 2i2 Digital Interface and then use it in Logic Pro X.

My question to you is.... The XLR that is currently hooked into the Shure 57 is a (4-Pin XLR Male).   How do I wire the (3-Pin Male XLR) so it works correctly with my Focusrite 2i2?  (4 post to 3 post)>

Hi.  Thought I could shed some light on this.  Your Shure mike is an older dual-impedance configuration with an Amphenol 4-pin connector.  Red and shield together supply the unbalanced, high-z connection.  Black, white/clear, and shield supply the low-z balanced connection.  For your application, trim back and tape off the red wire, and solder the shield to pin 1, the black wire to pin 2, and the white/clear wire to pin three on your male xlr connector.  That should supply the proper signal to your interface.

Good luck!

Commongrounder...... thanks for the reply! 

I'll do this tomorrow and let you know what happens!  ( just do not want to fry my Focusrite 2i2 our my MAC Logic Pro X 10.3!!!

I use to use this Sure Microphone when I played in bands years ago and used it to multitrack for years..... I just hate to let that microphone go.   If I need it, it has been a good friend.  I just bought a Beringer B-2 and just love it for multitracking in Logic Pro X..... I know it is a WAY better microphone for multitracking but MAYBE..... I will need the old Shure Unidine III (Shure 57) to mike drums or something else in the future.  Trying to NOT just throw it out or let it go...... "Save a Mic"  Thanks man!  Rich Leffler

Commongrounder...... good news!  Your guidance with my wireing now works!  I thank you very much for your suggestions.  Now i can stll use my Shure Unidine III (Shure 57) down the line with my multi-tracking.  Rich

Hi - 

Thank you for your straight-forward, succinct, expert explanation and guidance.  Much appreciated!

Hi Rich -

Looks like Commongrounder beat me to the punch with clear and concise guidance.  I'm glad this post was able to help you.

Hi

please advise the cables type required to connect the XLR and the speakon of the speaker JBL VRX932LA?

the lenthg of cables i need is 250 meter.

many thanks 

Ahmad

Hi Ahmad - 

Re-examine your engineering. Running cable that far will result in significant signal loss and degradation.

Longest bulk cable we offer:

Canare 4S11 4-Conductor Speaker Bulk Cable (200 m / Black)

Add the connectors: 

Neutrik NLT4FX Speakon 4-Pole Female Cable Connector

 Please contact us via e-mail if you have additional questions:  AskBH@BandH.com

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