In an age where wireless audio connections are becoming more common, for example in systems using network-sourced music using technologies such as AirPlay, Bluetooth and Wi-Fi, just about every audio system needs cables at some point.
Put simply, if you want any sound from your audio system, the chances are you’re going to need cables. But what are the various types of audio cables, which do you need, and how do you choose them?
by Thomas S.
October 6th 2025
There are two main kinds of cable in an audio system: interconnect cables, which connect source components like CD players and network streamers to amplifiers, and speaker cables, which link amplifiers to speakers.
Each cable is designed for a specific purpose – interconnects carry the relatively weak – and thus fragile – signals from players to amps, while speaker cables are built for the higher voltages and currents required to drive speakers. It is possible to cut corners with inexpensive cables, like the thin budget interconnects sometimes supplied with audio components or very thin ‘bell wire’. A sensible investment, though, in dedicated cables built for audio will maximise the performance of your audio electronics and speakers for improved sound quality.
Let’s look at analogue interconnect cables first, as these can have a major effect on the performance of your system. You know the old computer maxim, ‘garbage in, garbage out’? Well, signal loss between source components and amplifiers can’t be regained further down the audio chain, so high-quality interconnects should be considered a must-have.
You’ll probably encounter two kinds of interconnects – unbalanced and balanced. These titles reflect the layout of the conductors within the cables and their connection to the products they’re linking to. Let’s take a closer look at the two types.
Unbalanced connections remain the most common type of interconnects you’ll encounter. They use the simple coaxial RCA phono plug with a basic construction of a pin and collar to carry the positive and negative signals. The internal construction commonly features a single central conductor (usually of metal) for the positive feed, surrounded by (and insulated from) an outer shield of metal foil or a weave of very thin strands. This is designed to carry the negative connection and provide some isolation from outside interference.
Wrap all this in an outer jacket for protection, and you have an interconnect cable for a single channel of audio. Of course, you’ll need two of these to carry a stereo signal. Some inexpensive cables put the two channels together in a ‘figure of eight’ configuration, but in general it’s best to keep the two channels apart, each with its own insulation.
Although unbalanced cables are more or less ubiquitous in domestic audio systems, they do have a drawback: they are prone to picking up external electrical interference, typically heard as hum on the audio signal. The longer the run of cable, the more likely you are to hear it. Even if this interference isn’t audible, it can interfere with the audio signal on a more subtle level and can affect audio quality.
To combat this, balanced audio cables can be used between pieces of equipment designed for balanced working. Drawing on experience gained in the professional arena, these cables differ from unbalanced designs in that both the + and – connections have their own conductors protected by an outer shield. In this configuration, any interference picked up on one conductor will also be picked up on the other, but the two will cancel each other out due to the two being in opposite polarity.
As a result, such cables are favoured in setups with longer cable runs, where the power amplification is close to the speakers with the preamp some distance away, or when active speakers are used straight from a preamp or source component with its own volume control, such as a network player.
As an alternative to analogue cables as the interconnect between source components and amplification, digital cables are used in some systems. These have the advantage of being resistant to interference and should deliver excellent results, as long as the digital-to-analogue conversion in the amplification is at least as good as that in the source component. Indeed, some CD and network players are designed as transport-only devices with no onboard digital-to-analogue conversion. These devices are intended to be connected to digital inputs on the amplifier or preamplifier.
There are two main kinds of digital cable – electrical (essentially a specialised version of the same connection used for analogue hook-ups) and optical. In both cases, a single connection is needed to carry both audio channels or even multiple channels in a surround setup.
Essentially, carrying the digital datastream over a twin-conductor cable, like that used for a single analogue audio channel, is often generalised as a ‘coaxial digital’ cable, though a variety of connectors and cable configurations are used. Common configurations are RCA phono plug connectors, BNC connectors and XLR-plugged AES/EBU connectors, which use a balanced cable construction.
The important consideration here is that a cable designed for digital should be used for digital signals: cables designed for analogue audio will work but aren’t ideal. It’s all a matter of cable impedance (or to simplify, resistance): the standard for a coaxial digital connection using RCA plugs is a 75 ohm impedance (coincidentally, once familiar for connecting FM radio antennae). For AES/EBU connections, it’s 110 ohm.
As both coaxial and optical digital connections conform to the Sony/Philips Digital interface (S/PDIF), which combines both the signal and timing information in a single datastream, there is the potential for mistiming in the transmission. This leads to what’s called ‘jitter’ and occurs when the receiving device loses track of the timing signal. The device must then work hard to recover a coherent datastream on which the digital-to-analogue conversion can work.
A major cause of this is incorrect impedance in the digital cables, which can cause the signal to reflect within the cable, messing up the accurate transmission of the high-speed digital signals.
To further combat this, some proprietary systems have been developed that carry the clock signal and data on separate cables. There’s also the I2S (or Inter-Integrated Circuit Sound) connection, which replicates the way data is transmitted within digital components using a separate clock line as well as those for the left and right channels. It also features a ‘word select line’ to tell the receiver which channel each bit it’s receiving describes.
The problem is there’s no standard for an I2S connector. Some recent components use a multipin HDMI-type connector, but the connection doesn’t conform to the HDMI standard and there can even be variance between hardware manufacturers when it comes to ‘which pin does what’.
In theory, optical digital connections should be superior to those with metal-based cables. After all, optical is immune to interference. Optical ‘cables’ (they’re actually fibre-optic light-pipes) are also used for high-speed data transfer, so they must be better, right?
Most optical cables you’ll encounter will use the inexpensive TOSLINK connector, so called because it was developed by Toshiba. This connector type is fixed on the end of a light-pipe formed by a single strand of glass or plastic (or bundle of such fibres), covered by a protective jacket. How well that assembly is put together determines how well it performs. Prices range from almost nothing for a thin plastic cable all the way up to ‘high-end’ money for a glass core terminated in exotic versions of the TOSLINK connector. Some companies even make gold-plated TOSLINK connectors.
Yes, optical connections have a theoretical advantage in their immunity to electrical interference, but there’s a lot of potential for error resulting from reflections within the optical fibre. This is especially true where it’s joined to the connector and where the plug connects with the port on the devices you’re connecting.
There’s one more consideration: it’s easy to think that optical is good because, after all, CD is an optical medium read using a laser. However, the player converts those optical pulses into an electrical signal, so connecting a player to the digital input on an amplifier or DAC means the data goes optical-electrical-optical-electrical, which can introduce even more errors.
Did you know...
Some audio cables are designed with directionality, meaning the signal is intended to flow in one direction only. Manufacturers sometimes mark these cables with arrows indicating the correct signal path, from source to destination. While the science behind audible differences is debated, the idea is that shielding and grounding are optimised for noise rejection when used in the intended direction. It’s a subtle detail that can matter in ultra-sensitive setups.
Avoid running signal cables alongside the mains cables for your audio components: it may look neat but it’s asking for trouble in the form of signal interference.
There’s no such thing as the perfect way to connect a system: both analogue and digital have their advantages and disadvantages. Analogue is prone to interference, especially on long runs, though you can mitigate this with balanced connections (provided your hardware supports balanced working). For setups using long runs between preamp and power amps, balanced working is really the only solution.
In most domestic setups, the best advice is to keep the source-to-amplifier connections, whether analogue or digital, as short as possible. Reserve long runs for connecting amplifier and speakers, as the much larger signals in speaker cables are significantly more resilient when it comes to potential interference.
How much should you spend on audio cables? The short answer is, it depends. You can spend anything from pocket money to the price of a decent car on a pair of interconnects, so you need to consider the budget for your whole system and then invest a sensible amount on your cables.
It isn’t even the thicker or more impressive looking a cable is, the better it will sound. Instead, choose something that feels robust and well finished. Check practical things like whether those big, fancy plugs are so large that they won’t fit your hi-fi components. And buy only the length you need; it's better to invest what you otherwise would have spent on a shorter, higher quality cable.
Also, buy cables from a brand you’ve heard of, rather than an unknown name claiming the world for its products: cables do fail or break, so it’s good to know you have some kind of guarantee to have them replaced or repaired.
And remember, once those cables are in place, no-one’s going to see them. So don’t be swayed by garish finish, exotic materials or magic devices installed into the cable: buy good, not gaudy.
Look after your cables and they’ll last forever – well, almost.
Buy the right length of cable for you needs; neither too long, in which case you’ll have to find somewhere to hide the excess, or too short, where you risk stretching the cable and putting strain on both plugs and sockets.
Take care with cable layout behind your hi-fi equipment. Try to keep cables apart from each other and avoid winding excess cable tightly. Invest in some labels to indicate what connects to what, so you aren’t forced to disconnect every cable to swap something over.
Avoid running signal cables alongside the mains cables for your audio components: it may look neat but it’s asking for trouble in the form of signal interference. Where mains cables do meet signal cables – also digital cables– try to ensure they cross at right angles.
When it comes to cleaning the cable connectors, you can invest in all kinds of products, such as contact cleaner, which is both inexpensive and effective. However, simply unplugging everything and plugging it back up every six months or so will be sufficient for most owners.
Good cables don’t just carry signal – they carry your sound. By choosing the right length, keeping your layout tidy and doing occasional maintenance, you'll avoid interference and extend the life of your setup. It doesn’t take much effort, but it makes a big difference. Look after your cables, and your system will thank you with great performance for years to come.
Within reason, yes, provided they’re built to the correct specification. If possible, try to compare the different levels of cable in a manufacturer’s range at your local dealer. When you stop hearing a difference, stop moving up the range.
The old rule of thumb suggested you should spend about 10% of the cost of your system on Hi-Fi interconnects and speaker cables. For entry or lower end setups, that might be a little excessive, but in the rarified atmosphere of high-end hi-fi, you probably don’t need to spend that much to get excellent performance – though you can also spend an awful lot more.
Gold or silver plating helps with the electrical conductivity at the point where your cable meets your audio components. Silver is the best conductor but can tarnish in time when in contact with air, so will need more cleaning. Gold is almost as good and is inert (so no tarnishing). However, it’s relatively soft and easily damaged. Plug and unplug your cables a lot, and you may start to scrape the coating off the plugs. Rhodium plating, on the other hand, is much more durable and has similar conductive properties to gold.
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