Posted on Tue, 27 Jan, 2015
Posted by Raven

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Customising to taste is a big part of what makes hi-fi fun – it’s all about the detail! And yes, those details include the wiring. And yes, that’s customisable too! If you want to tweak the sound the suit you – and you alone – then its worth looking into the wonderful world of wiring. Not only that, but the vast majority of speakers/amplifiers won’t come ready supplied with cables – so it’s worth being prepared.

It was once – quite famously – believed that such things as ‘cables’ made very little difference – if none at all – to the quality of the sound. That has long been proven as not quite the case. Far from it, in fact it’s now recommended that you spend 10% of the value of your system on some cables to compliment them. If you have a high-end system, only a high-end cable will suffice in making the absolute most out of it – and that goes from everything from the mains cable, through to the audio interconnects and everything in between – including speaker cables! There was once a time that hardcore audiophiles would use 3 core cable – that’s cable with a solid core – to service their system. But those days are long gone!

If you have a hi-fi or home cinema system, the chances are you’re going to come to blows with wiring at some point. It can get a bit hot and heavy at times, so we’ve come up with a little guide on the whats, whys and hows of wiring, to help guide you through the process. Starting from the top…

What is speaker wire?

Speaker wire is used to create a connection between the loudspeakers and the amplification. The most common – and the most effective – core material is copper: inexpensive and conducts beautifully. Most speaker cables feature two or more electrical conductors, and some form of insulating casing, often made of some sort of plastic.

The world of speaker wire is very varied, and there are dozens upon dozens of options to consider – none of which we will be going into here (we like to keep it simple, where we can!). But the the three most important things to consider when it comes to selecting your wire are these basic principles:

  • Conductivity

  • Length

  • Thickness/Gauge

The best thing to aim for his a high conductivity and a high thickness, with a lower length. Practicality will often dictate otherwise length-wise, but by keeping the length low, you keep the resistance low. This means less power is required. Of course having a relatively short speaker cable isn’t always a possibility, but all that means is you’ll require a more powerful amplifier. Another thing to remember is the lower the gauge, and the lower the gauge, the thicker the wire.

gauge

Which gauge to chose is very dependent on a number of factors, other than length, and will involve some calculations involving the impedance . And it’s times like this that a chart says it better than we ever could. An AWG (American Wire Gauge) is the unit in which the gauge of the wire is measured. The lower the gauge, the thicker the cable. We’ll get onto ohms in a moment.

guage_chart

Ohms & Impedance

ohms-law-illustrated

To answer the ‘what are ohms and impedance and why are they calling all the shots?’ If you want an in depth answer to that question, this is a good place to find it. But we’ll give you as close a summary as we can!

In short, an ohm is the unit in which impedance is measured, and the property of a speaker that restricts the flow of electrical current. The impedance of a unit is fixed, which means it is a reliable unit of measurement for loudspeakers. It is pretty imperative to understand the output of ohms from the amplifier and the impedance of the speaker, as not doing so can result in a blown power amplifier. Or worse: poor sound quality from the speakers!

Ohm’s Law states that in an electrical circuit, current flow is directly proportional to voltage and inversely proportional to impedance.  Mathematically, this becomes: Current (in amperes or I) equals voltage (in volts) divided by impedance (in ohms).

By knowing the voltage and the total current, it is possible calculate the total impedance of all the speakers together by dividing the voltage by the total current. To quote from the above linked article:

‘As an example, if a (solid state) amplifier is producing 10 volts AC to an 8 ohm speaker, the current in the speaker will be 10 volts / 8 ohms or 1.25 amperes. If the amplifier output is increased to 20 volts to that 8 ohm speaker, the current becomes 20 Volts / 8 ohms or 2.5 amperes. So increasing the voltage increased the current. If the voltage decreases back to 10 volts, the current will decrease back to 1.25 amperes. Now, if our amplifier with 10 volts output is connected to a 4 ohm speaker, the lower impedance will allow more current to flow. The amount will be found by 10 volts / 4 ohms = 2.5 amperes.  If we use a 2 ohm speaker, even more current flows: 10V/2 ohms = 5 amperes.’

You got that? Great. Admittedly the above is only important when you’re selecting the gauge and length of your wire, or when wiring up multiple speakers (as the output will be evenly distributed between them, potentially resulting in too low an impedance for speaker performance. The impedance of the speaker and the output ohms of the amplifier will almost always be clearly stated, it’s just a case of remembering to check when selecting your wire.

Moving very swiftly on…

Wiring Options – Single or Bi?

When selecting your wires, you can chose from either single-wired, or bi-wired.

wiring_options

 

A single-wired wire is, as the name suggests, a single wire consisting of two cores, typically. Bi-wired wires typically consist of a four-cored wire with two wires at the amp end and four at the speaker end, each feeding the drivers separately from their own insulated conductor.

Bi-amping is the next step up from bi-wiring, and is only of use to those who have two separate power amps in their system. A bi-amping wire involves four wires on the amp end and four on the speaker end, each their own insulated conductors.

Amping Options

Many loudspeakers will only require a single pair of standard speaker cables. However, as always, there are exceptions to that rule, particularly with higher end systems which feature clever little hacks to improve the sound quality.

Bi-Wiring

bi-wiring

In a regular, single-wired system, a single pair of wires carries the full-range signal from the amplifier to each loudspeaker. Simple. A bi-wired system, however, uses two pairs of wires per loudspeaker: one carries the higher frequencies and the second carries the middle and low frequencies. As with everything else hi-fi, separation is the key to improved sound. This is a fairly easy tweak to accommodate though, and only requires an extra set of speaker cables.

Bi-Amping

BI-AMPING

As the name suggests, bi-amping typically involves the use of two power amplifiers, each used to separately power a loudspeaker. There are a two main subdivision of subdivisions of bi amping:

 

  • Active – involves the use of an active crossover which will split the electrical signal into high and low frequencies before it reaches the amplifiers, allowing each channel to only reproduce the range of frequencies required
  • Passive – there will be passive crossovers built into the speakers which passive bi-amping will utilise, with each amplifier channel reproducing a full-range signal to drive separate high and low frequencies

Active bi-amping is more sonically beneficial than passive, as active bi-amping will allow for a greater level of separation between the frequencies. Passive bi-amping doesn’t involve any extra input, bar the extra pair of speaker cables and the second power amplifier and active will require the purchase of an active crossover (if you want one of those, it’s best to get in touch).

Termination

Plugs (1)

We have already got a dedicated blog to the termination of cables, but it’s always worth a refresher!

Banana Connectors

Most commonly referred to as a banana plug for the male and a banana jack for the female, the banana plug is typically a four leafed spring tip that enables a single wire to be connected firmly to the equipment. These have been in common use for speaker-to-amp connectivity since the mid to late 1920s.

Spade Connectors

Shaped like a crab claw, the spade connectors – commonly referred to as spade lugs – are the next most common type of speaker cable termination. Spades are a popular choice, owed to their tight fit, and expansive surface area. They not quite as easy to swap around as banana cables, but still offer heaps of convenience over bare wire.

BFA Connectors

Much less common – but still worth a mention – are BFA connectors, also known as Deltron plugs. Although use of these connectors has gradually fallen out of favour, you will still find them in use in Cyrus and some older Linn units.

Some brands, such as Naim, offer their own specially designed connections and terminations on their products too, which is certainly worth looking into if you are the owner of such a product.

High End Speaker Cable

genesis_silver_spiral

High-end cables are – and will likely continue to be – one of the most hotly debated topics in the world of both hi-fi and AV. But we have come to believe that the same rule applies to cables as it does to everything else hi-fi related: the more you spend, the more you get. Speaker cable technology has improved hugely over the years. Gone are the days when a solid copper core and a waxed paper or fabric jacket were thought to be enough – tweaks to the materials, to the connections, to the wrapping and to the core. All of which are designed to lower the resistance, improve the conductivity and – quite crucially – shield the wire from interference. And it’s this lack of interference which forms the basis of one of the fundamental principles of hi-fi: isolation is key to a pure, unadulterated sound.

Any hi-fi dealer worth their salt will recommend putting aside 10% of their budget for the cabling. An investment in a hi-fi system means an investment in all of the components – including the cabling.

 

Wiring Speakers

how_to

The actual act of wiring up your speakers is very simple, the tricky part us making sure you have the correct wires for your speakers. Check for:

– Gauge – the thickness of the cable, dictated by the output of the amplifier and the impedance of the speakers, and the length of the cable

Wiring of speaker – your speaker will either have two or four outlets on the back, which will dictate whether or not you require bi-wired cables

– Termination – banana plugs and BFAs will be inserted into the outlets, while spades will ‘hug’ binding posts. Most speakers will accomodate both of these

– Keeping the phase – each wire consists of two conductors, a positive and a negative. If you connect these ‘out of phase’ i.e. the positive to the amplifier and the negative on the speaker and vice versa, sound quality will be poor as this will effect the sound stage. To combat this, most speaker cables are colour-coded, or feature a white stripe on the jacket of one of the conductors (in the speaker wire)

– Tightness – tightly wiring your speakers is essential. It ensures a continuous, and solid connection, which means your getting the absolute most out of the arrangement. Correct termination is essential in ensuring your connection will last, and sound quality will last for years

– Length – resistance plays a huge factor in the performance of speaker cables, as we said before, the longer the cable the higher the resistance. Now, it’s not always possible to keep the length of the cable down, but it’s always worth remembering: the shorter the cable, the lower the resistance. The lower the resistance, the better the performance. The better the performance, the better the sound quality

The world of speaker wiring is vast and complex. So much so, this overview is exactly that: an overview. As always, if anything is unclear, it’s always best to speak to someone who knows what they’re talking about – and luckily we have a few of those at your disposal.

You have your speakers, you have your amp, you have something to play through it all. Don’t let the cables get between you and some beautiful high-fidelity music.

Nobody wants to be that guy.

Frustrated man with tangled wires

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