Shielding protects your speakers from signal integrity issues. If you love listening to uninterrupted sound from your speakers, then you should consider shielding the wires. In this article, we look at the why and how to do that.
In most cases, shielding speaker wires is not necessary. However, you can shield your speaker wires if they are very long and driving powerful speakers, especially if other electronics or many cables are closeby. This may help protect your audio signals from unwanted noise.
Read on for further information.
What Are Shielded Cables?
Shielding is a foil is wrapped around your cable that prevents unwanted noise from entering the wires and prevents noise from graduating outside the cable. In other words, shielded cables are electrical cables with insulating conductors wrapped in standard conductive layers.
The shield can be made from strands of braided copper, spiral copper tape, or any other conductive polymer. Because of the shielding material, shielded cables are thicker and more rigid. Besides, they demand more excellent care when working with them as compared to unshielded wires.
What Is A Shielded Cable Used For?
You may therefore be asking, what is shielded cable used for? Shielded cables are mostly used in industrial installations where other equipment nearby may generate electromagnetic interference (EMI).
For instance, you can use shielded cabling to secure data in the cable during the transfer from degradation due to exposure to EMI. It should be understood that EMI is very common in industrial settings, data centers, and other settings where electrical equipment or computer technology is in heavy use.
Generally, EMI is generated by external sources and may affect an electrical circuit through conduction, electromagnetic induction, or coupling. The disturbances resulting from EMI can reduce the performance or even cease the functioning of a circuit.
Besides, where a data path exists, error rates could be as high as a complete loss of signal or data.
The variable electrical voltages and currents that cause electromagnet interference can result from artificial sources such as mobile phones and vehicle ignitions and natural sources such as radiations from the sun and thunderstorms.
Should I Shield My Speaker Wires?
We should mention again that shielding speaker wires is not necessary in most cases as speaker cables are already high-level cables. Trying to remove noise from speaker cables can be meaningless. It will not make a difference in most cases. However, you can shield long speaker wires which allows you to introduce enough capacitance to reduce noise.
Mostly, shielding is done on speaker-level cables as a preventive means to secure other low voltage wires running near them.
Wires used in antennas and microphones are good examples of low voltage cables that will be highly affected by Electro-Magnetic Induction (EMI), crosstalk, Radio Frequency Interference (RFI), among others from adjacent cabling.
It is, therefore, expected that if unshielded low-voltage cabling such as a microphone runs parallel to or near the speaker cabling, there will be much more interference from the speaker lines to the sensitive low-voltage signal lines.
EMI commonly disrupts mobile phones, radios, and televisions. Therefore, shielding of speaker cabling is recommended when you share the same direct cabling path with other low-voltage cabling carrying low signals.
The shielding reduces both the electrical noise and volume, thereby lowering its effect on the signals and the transmission. Besides, it reduces all forms of electrical radiation from the cables.
Should I Elevate My Speaker Cables?
In terms of reducing noise, you should also keep in mind that you should also elevate your speaker cables (keep them off the ground) so that if there is any noise leakage, it doesn’t make contact with the actual ground.
Should I Byt Shielded Speaker Cables?
Buying shielded speaker cables is not necessary unless they aren’t much more expensive than regular unshielded speaker cables. This is because the shielding won’t make that much of a difference.
Types of Speaker Wire Shielding
Shielding speaker cables can be done in different ways using different types of shields. Before we describe the process, let’s look at the three commonly used cable shielding applicable to speaker cables.
1. Braided Shielding
This is a woven mesh of tinned or bare copper wires. It provides a low-resistance path to the ground and can be between 70% to 95% effective.
The shield is, therefore, more effective as copper has a higher conductivity compared to aluminum. The braid will, however, add more weight and cost to the speaker cable. Besides, it reduces the flexibility of the cable depending on how tight the mesh is.
2. Spiral Shielding
Spiral shielding for speaker cables is quite similar to braided shielding. However, instead of being woven together like in the braided shields, the copper strands are made to spiral around the conductor.
Spiral shielding is, therefore, more flexible compared to braided shields. Consequently, it offers more opportunities for gaps in the shield, allowing it to easily open and absorb interference mainly occurring when the strands are not spiral. Besides, it is quicker and cheaper to manufacture.
Spiral shielding will therefore give you much better results at lower prices when shielding speaker wires.
How to Shield a Speaker Wire From Interference?
Follow the step-by-step guide below to ensure that your speaker wires are appropriately shielded from electrical interference.
When wiring your home, use a shielded conduit to reduces the chances of interference. Remember, shielded conduits are more expensive than non-shielded ones. Therefore, you can reduce their usage unless you need to have different cables running parallel and in a close proxy. Also, you will need to buy flexible cables if the wiring will need to go through corners.
Wrap the magnetic foil around the speaker cable to shield it from interference. It is cheaper to buy this material than shielded cables, but it will take you longer to wrap it around the wiring. You will therefore need to evaluate the cost of wiring your home with shielded cables.
Use shielded power cables for all your home appliances. This is because some televisions, lights, and clocks will generate electrical fields even when they are not in use. However, the cords are more expensive and should be used only on appliances that are likely to cause noticeable interference.
When laying or wiring, be sure to maintain a distance of at least 1 foot between audio, telephone, and electrical wires. And even if the cables must be placed nearby, do not have them in the same conduit.
Keep checking your connections to ensure that frayed wires are not causing EMI to your speakers. Some speaker wires are more likely to fray at the ends, and these will sometimes cause sounds similar to interference on your audio. If this happens, replace the cables with new shielded speaker wires.
Difference Between Instrument Cable And Speaker Cable
the significant difference between instrument cables and speaker cables is that instrument cables have much smaller wires and are shielded. In contrast, speaker cables are not shielded but have larger wire gauges.
Also, speaker cables have two independent wires that are either black and red or black and white. The cables do not have any form of foil wrap or braided cables on them.
On the other hand, instrument wires have some form of shielding, which can be foil wrap or braided wire mesh. The shielding is maybe on one or two of the cables.
How To Tell The Difference Between Speaker Cable And Instrument Cable
Like we have mentioned, telling the difference between a speaker cable and an instrument cable is simple. While an instrument cable contains a shield and signal wire, a speaker cable contains two similar wires without a shield.
Besides, while speaker cables are designed to carry strong enough signals to power the speaker from amplifiers, instrument cables can only handle low-level audio signals.
Will Shielding Produce The Best Speaker-Level Audio Signal?
As a general rule, speaker-level signals are much higher than the intrusion level of EMI signals. However, exceptions to this rule can occur, and these can be avoided by using twisted or braided conductor legs to reduce or eliminate signal pick-up from outside forces.
However, any attempts to shield the speaker cables, such as using the braid or foil, cause an increase in the capacitance of the speaker cable. The added capacitance will have more negative effects on the amplifier feedback circuitry. It will most likely cause signal overshoot resulting in an audible difference in the audio output, mainly if you use a low-quality amp.
Therefore, shielding a speaker wire may not produce cleaner audio signals but will protect it from unwanted noise from electric transformers, nearby radio antennas, fluorescent ballasts, large motors, etc.
What Are Speaker Wires Made Of?
Modern speaker wire consists of two or more electrical conductors individually insulated by plastic (such as PVC, PE or Teflon) or, less commonly, rubber. The two wires are electrically identical, but are marked to identify the correct audio signal polarity. Most commonly, speaker wire comes in the form of zip cord.
How Far Can You Run Speaker Wire
Speaker wires can definitely be too long. Ideally, the maximum length a speaker wire should be run through is about 50 feet. Anything above 50 feet is considered too long. The length of the run of speaker wires from amplifiers to speakers affects the quality of the sound produced by a system.
What Is The Maximum Length Of Speaker Cable?
While in theory, heavier wires can have longer runs, recommended household audio lengths should not exceed 50 feet (15 m). The gauge numbers in SWG (standard wire gauge) and AWG (American wire gauge) reduce as the wire gets larger.
What Gauge Speaker Wire Is Best For Car Speakers?
For most cases using home or car speakers (not subwoofers), 18 gauge (18AWG) is fine. 18AWG wire is good for about 50W for 4 ohms (car) speakers and 100W for 8 ohms (home stereo) speakers. For higher power systems or longer lengths, 16 gauge is a great choice.