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A Guide to Speaker Wire: Which Is the Best Gauge for Your System? 

Speaker Wire 101 Featured Image
Updated: January 22, 2020

Speaker wire might seem like such a dull subject, right?

I mean, who cares about those annoying wires that just make your room look a bit messy? The fun stuff is the amplifier and speakers!

So, you just buy the first speaker wire you come across in your hurry to get on with the show.

Well, you might be surprised to know that there are loads of exciting things to learn about speaker wire.

Yes, as with many things in the world of home theater, there's plenty of technical stuff to get your head around. 

And, some people get very over-excited about this subject. Which is fun!

So, if you want to understand more about the exciting world of speaker wire, strap yourself in and enjoy the ride.

What Is Speaker Wire?

Speaker wire is used to connect an amplifier to a set of speakers. In some parts of the world, it is also known as speaker cable.

An amplifier sends an electrical current audio signal to a speaker. The current powers the speaker drivers and this is how they make a sound.

Therefore, speaker wire is just a means to conduct electrical current. Just like the wire that sends power to your lamp or television.

What Does Speaker Wire Look Like?

Speaker wire with the insulation stripped at the end

Speaker wire looks like the picture above - although there are many different types.

Traditional speaker wire has two conductors for connecting to the positive and negative connectors on amplifiers and speakers. Unlike the picture above, the wire usually has the same type of conductor for both cores - usually copper.

The inner core is insulated on the outside by some form of plastic. Before connecting to your speaker or amplifier, the insulation needs to be removed at the end to expose the bare wire.

The bare wire can be connected directly to the speaker connectors. Or, sometimes a form of termination is added to make the connection easier and more reliable.

See my guide on how to connect speaker wire for more information on this.

Do I Have to Use Speaker Wire?

Not really, no. 

So, what is the difference between a speaker wire and plain old electrical wire? Not a lot.

In theory, you could use anything that will pass electric current from A to B - the cable that is used to power your lamp, for example, or a wire coat hanger…

However, in practice, most people will buy 'speaker wire'. This comes in different sizes and at various price points; you just need to decide which is the right choice for your equipment.

You will hear many opinions that you need to buy an expensive audiophile speaker wire to get the best sound in your room.

I don't subscribe to that view. However, if you think it helps, you should buy whatever you are comfortable with.

What Is the Advantage of Buying Proper Speaker Wire?

One advantage of buying wire that is designed to be used for speakers is that one side will be clearly marked with a line or with ridges. 

This makes it easier to connect positive to positive and negative to negative at the amplifier and speaker.

It will also have a flexible and resilient outer insulation that makes it easy to install - and reduces interference from other electrical signals.

However, you will also see other features of dedicated speaker wire that are supposed to improve performance. Some of these include:

  • Oxygen-free copper
  • Cryogenic treatment
  • Directional cables
  • Magic fairy dust (OK, I made this one up!)

I'm not going to tell you this is wrong. There have been arguments raging for years about if it is possible to hear the difference between different types of speaker wire.

So, in the end, you'll need to make your own mind up. 

But, I've yet to be convinced there is any significant difference in performance between a simple wire and a 'special audiophile' speaker wire.

Some brands offer speaker wire with connectors already fitted at each end of the wire. This can be useful if you want a reliable connection and don't want the trouble of doing it yourself.

But, it's not necessary – and, in most cases, you can always use bare wire for the connection.

What Makes Good Speaker Wire?

The main feature that a speaker wire needs is a core with low resistance.

Less resistance means more signal will reach the speaker from the amplifier.

This is why copper has always been used as the core conductor for electrical and speaker wire. Copper is an excellent low resistance conductor for electricity.

Speaker wire should also have low capacitance and inductance – but these are less important than resistance.

Apart from that, a speaker wire should have flexible and durable insulation outside the core.

Flexibility is needed to make it easy to install the cable in tight spaces. 

The insulation should also protect the core from electrical interference and oxidization - and not deteriorate over time and contaminate the core.

What Type of Speaker Wire Do I Need?

There are two main things to look for when buying speaker wire; the material that is used for the internal conductor and the thickness of the wire.

There are other differences that you will see, but most of it is marketing smoke and mirrors to make you buy the wire. I'm going to stick to the fundamentals.

1. Wire Core Material

There are 3 main conducting materials commonly used to make speaker wire (you may find more exotic versions if you look hard enough):

  • Copper: the main option since the early days of speaker wire. It has long been used in many industries to conduct electricity. Speaker wire is typically stranded copper which comprises many thin lengths of copper bundled together. You can't go wrong with this.  
  • Copper-Clad Aluminium (CCA): as copper became more expensive, CCA became more popular because it was cheaper to make - and buy. CCA wire is also typically stranded. Each strand has an aluminum core with a thin outer coating of copper. This works just fine. However, it has a different resistance to copper, so you might need to get a thicker cable than with copper for the same cable run.
  • Silver: popular in more 'audiophile' speaker wire products. Silver has greater electrical conductivity than copper, and so is supposed to be a better solution. The cable is likely to be silver-plated copper rather than solid silver – although this does exist. However, if the resistance is low enough for the length of cable that you need, there is unlikely to be any audible difference between copper and silver. If you don't agree, that's fine, I'm not going to stop you buying silver-plated speaker wires.

2. Speaker Wire Gauge Types

The gauge of speaker wire refers to the thickness of the cable.

It is slightly confusing (for me at least) because the higher the gauge, the thinner the cable. This has always seemed a bit counter-intuitive to me.

Still, nobody asked my opinion when they came up with the idea, so I guess I'm going to have to suck it up!

The American Wire Gauge (AWG) is the standard used in North America. It hasn't been specifically created for speaker wire but is used in a range of industries that use different wire types. 

You might also hear it called the Brown & Sharpe wire gauge.

Although the AWG specifies a wide range of sizes, the most common sizes for speaker wire are probably 12, 14, and 16-gauge. These will be ideal for most wiring duties in an average home theater and stereo music system.

Speaker wire gauges - AWG and DiameterSpeaker Wire Gauges - AWG and Diameter (not to scale)

I would like to say that this standard is recognized around the world. Wouldn't that be easy? But, it's not.

There are several different wire gauge standards used worldwide. Here is a wire gauge comparison download which might be useful if you want to compare wire sizes around the world.

In the UK, speaker wire is often measured by cross-sectional area in square millimeters. This is not the same as the diameter. And, sometimes the AWG is quoted.

How confusing is that?

Here is a chart which shows the comparison of the most common AWG speaker wire sizes and cross-sectional area:

Speaker Wire AWG & Cross Section Comparison
AWG Cross Section (mm²)
10 5.3
12 3.3
14 2.1
16 1.3
18 0.82
20 0.52
22 0.32
Source: sengpielaudio.com

The common wire sizes for speakers in the UK are:

  • 0.5 mm²
  • 0.75 mm²
  • 1.5 mm²
  • 2.5 mm²
  • 4.0 mm²

So, it's not an exact match to the table above, but you can see the approximate equivalent size in AWG.

For example, 1.5 mm² is about the same as 16 AWG - and 2.5 mm² is roughly equivalent to 14 AWG.

The gauge of speaker wire is the most important feature when deciding what to buy.

Why? Because as the wire gets thicker, the resistance decreases. And, to get the best audio performance, we want the resistance to be below a certain level.

Is Thicker Gauge Speaker Wire Better?

Sometimes.

A thicker gauge wire will have less resistance (impedance).

Less resistance is good.

If resistance is kept below a certain level in your system, then it won't degrade the audio passing from your amplifier to your speakers.

If you need long cable runs, then it is more important to use thicker wire to keep the resistance low.

However, it isn't really a case of thicker wire being better or worse, it's a case of getting the right gauge wire for the job.

Depending on the length of the speaker wire that you need, a thinner speaker cable may have the same audio performance as a thicker one.

But if you need to run a cable for a longer distance then, yes, a thicker speaker wire might be better.

What Is the Best Gauge for Speaker Wire?

What is the right size speaker wire for your room? Well, it depends on a couple of factors. The best speaker wire gauge for your system will depend on:

  1. how far you want to run the cable
  2. the type of material that the conductor is made from
  3. the impedance of the speakers

Respected loudspeaker engineer Roger Russell says that the ideal resistance for a speaker wire is less than 5% of the rated impedance of the connected speaker.

If so, then there will be no audible effect on the sound coming from the amplifier.

I know what you're thinking. "That's all very well, Paul, but how the heck am I supposed to figure that out?".

Fortunately, Roger has also produced a simple table to make this clear.

Here are his guidelines for 4, 6 and 8-ohm speakers connected with two-conductor copper wire. That should cover most speakers designed for the home.

Roger also has the numbers for 2-ohm speakers on his site, so check that out if you need those.

Maximum Speaker Wire Length*
Wire Size (AWG) 4 Ohm Load 6 Ohm Load 8 Ohm Load
10 100 feet 150 feet 200 feet
12 60 feet 90 feet 120 feet
14 40 feet 60 feet 80 feet
16 24 feet 36 feet 48 feet
18 16 feet 24 feet 32 feet
20 10 feet 15 feet 20 feet
22 6 feet 9 feet 12 feet
*For Two Conductor Copper Wire. Source: www.roger-russell.com

As you can see from the speaker wire gauge chart above, if you have 8-ohm speakers, then even a skinny 22 AWG wire can be run up to 12-feet with no loss of audio fidelity.

That might be plenty for your front left, front right and center speaker.

Not that I would necessarily suggest you buy 22 AWG wire. Most systems will use 16, 14 or 12-gauge AWS wire.

16-gauge copper wire can run up to 48-feet with 8-ohm speakers. So, if you want a wire size that will suit most circumstances, then a 16-gauge copper wire is probably a good fit.

For speakers with a lower impedance, then you might go with 12 or 14 AWG just to be safe.

Even though the table refers to lengths up to 200 feet, you wouldn't want to run cable this far. Roger suggests a maximum cable run of 50-feet.

What About CCA Wire?

You shouldn't forget that this data refers to copper speaker wire.

If you buy copper-clad aluminum wire, then this will have an increased impedance compared to copper.

Roger Russell doesn't provide these figures, but just bear this in mind when you are buying your cable.

As a rough rule-of-thumb, I would get the next thickness up to be on the safe side. 

So, if 16-gauge copper wire is fine for your room, then maybe get 14-gauge if you are buying CCA.

Of course, this may cancel out the cost savings of buying CCA instead of copper! Life is full of tough decisions.

For short cable runs – say 6-feet and under - it really doesn't matter which you buy. You are unlikely to hear a difference. 

If in doubt, and assuming you can afford it, just buy copper cable.

My Speakers Are Rated at 8-Ohm but They Go Lower than This – Which Gauge Wire Should I Buy?

Great question! 

Previously I said that the wire gauge that you buy depends on the impedance of the speaker.

However, a speaker's given impedance is nominal. This means that it is an average value and at certain frequencies, it can go above and below the nominal figure.

If so, how do you work out the best wire gauge?

First, I would find out from the manual/manufacturer of my speakers what the minimum impedance is.

Then, if I wanted to be sure of getting it right, I would use this as the impedance for my speakers. 

Now, you have plenty of slack when working out the best wire gauge for a cable length – so the chances are it won't make a difference.

But, if you are close to limit for a particular gauge, then you might want to consider the minimum impedance of the speaker rather than the nominal value.

Either that or just get the next size up anyway.

What Is the Recommended Speaker Wire Gauge for Home Theater and Surround Sound?

Choosing the correct speaker wire gauge might seem important for audiophile stereo speaker systems. 

But what about home theater and surround sound? What is the correct speaker gauge for this?

Well, the rules are the same. We are still using amplifiers, speakers and wire.

So, just select the correct gauge depending on your speaker impedance and the length of the cable run.

If you want a quick answer, 14-gauge AWS speaker wire should cover most solutions with no problems. And, most people will be fine with the cheaper 16-gauge AWS.

But, if you want to be sure, take a look at the maximum wire length table above and make the right decision for your room.

What Is the Best Speaker Wire?

If you have read the previous points, you will know that I don't think buying expensive speaker wire is worth your time – and money.

If you haven't read the previous points, then before buying speaker wire, I think you should.

Are expensive brand name products the best speaker wires that you can buy?

Well, if you think that it improves the sound in your room, and it makes you feel better buying it, then that is the best speaker wire for you.

But I'm not going to recommend any brand, as I don't think you need to overthink this.

Buy a reputable brand if you wish - but their basic wire is all you probably need. You can also get unbranded copper speaker wire very cheaply that will do just fine in most cases.

Just get the right gauge for the job.

In my opinion, the best speaker wire is simply the correct gauge for your system while taking into account:

  1. the impedance of your speakers.
  2. how far you need to run the wire from amplifier to speaker. 

Then, it just needs to be well-made with a copper conductor.

If you want to save some money, then buy some CCA wire. But copper is the best way to go if you can afford it.

If you want to pay a little more for pre-terminated speaker wire with banana plugs or spades already connected on the end, then that's fine.

But what happens if you change your speakers or amplifier and want a different termination on the end?

It's not difficult to connect the termination yourself. While you can solder these connectors in place, most will just screw on and are perfectly acceptable.

What Is OFC Speaker Wire?

OFC stands for Oxygen-free Copper.

OFC is copper that has been refined to reduce the level of oxygen. However, it still contains a very small amount of oxygen and so it isn't technically 'oxygen-free'.

The theory is that this purity will aid electrical conductivity – and therefore it has become popular for making speaker wire. 

It's another way to convince you to buy the wire. Because your sound system will improve if you buy OFC speaker wire.

The copper that is regularly used for electrical purposes (C11000) has a purity of 99.9%. OFC has a purity of 99.95%.

Will that extra 0.05% actually make a difference to the sound coming from your speakers?

Probably not. 

There's no harm buying OFC speaker wire. It might be all that is available. Just don't believe the hype.

I Really Hear a Difference with Expensive Speaker Wire

That's great. You can spend your money how you like. Whatever works for you.

How Much Should I Spend on Speaker Wire and Interconnects?

A common rule-of-thumb is to spend 5%, or maybe 10%, of the cost of your sound system.

That's a reasonable ballpark if you want something to go by, I guess.

However, I don't really feel the need to set a fixed number. Just buy the right cable for the job.

For speaker wire, just work out the right gauge for your system and get some basic copper wire.

Should I Install Expensive, Thick Speaker Wire for My Front Speakers and Cheap, Thin Wire for My Surrounds?

This is a common way of thinking. In the past, I've done it myself.

The thinking is that thicker wire is better quality, so I should use this on my most important speakers at the front.

The surrounds are less important, and further away, so I can save some money and buy cheaper, thin speaker wire.

The funny thing is the opposite is true. 

The thicker wire has less resistance and so should be used in the longer cable runs. For the shorter runs, you can get away with much thinner wire.

In the end, don't overthink this.

If your maximum cable run is less than 48-feet – and you have 8-ohm speakers – just buy some simple 16-gauge copper wire and use it for everything.

Should I Buy Copper or CCA Speaker Wire?

If money isn't a problem, just buy copper. It's tried and tested, and you can sleep easy at night.

If you want to save money, then CCA (copper-clad aluminum) is fine. Just make sure that you consider the higher resistance compared to copper when you calculate the best gauge to buy.

If you only need short cable runs, or you only have a budget amplifier and speakers, you're unlikely to hear the difference whichever you buy.

What Is the Maximum Length for Speaker Wire?

There is no exact number on how far you can run speaker wire. General opinion seems to be that over 50-feet might begin to give audible differences in sound quality – regardless of the thickness of the cable.

Should the Length of Speaker Wire Be the Same to Both Speakers?

Try to make it roughly the same, but don't lose any sleep if it's not exactly right.

In theory, you might get a slightly different sound from two speakers if one has a different impedance in the cable run.

But it's unlikely to make much difference in the real world.

Of course, try not to go to extremes. You know, by having a 3-foot wire to your left speaker and then have the whole 50-foot reel of wire connected to the right.

That would just be silly.

And anyway, if you are connecting surround sound speakers around your room, it might be impossible to get these matched exactly. 

Who knows what manner of furniture and wall furnishings you will need to avoid while running wire back to your amplifier? Your room is hardly likely to be exactly symmetrical now, is it?

Which Is Positive and Negative on Speaker Wire?

Speaker wire doesn't have a positive and negative.

The speaker and amplifier connections have positive and negative terminals.

You just need to make sure that the positive terminal on the amplifier is connected to the positive connection on the speaker. The same with the negative side.

Positive and negative terminals on a spring clip speaker connectionPositive and Negative Spring Clip Speaker Connections

This is why speaker wire has one side marked in some way. Usually a line or maybe with a + and – sign. Or, some other marking. Look closely and you will see it.

Just make sure the side with the marking is connected to the corresponding terminal at either end.

But it doesn't really matter which way round you do it. You can swap them around if you like.

Is the same piece of wire connected to positive at both ends? Is the other wire connected to negative at both ends?

Yes? Sorted. Make sure you do the same for every speaker.

Should I Replace Old Speaker Wire and Connectors?

I wouldn't get too hung up about this. However, if your cable and connections are a year or two old, and they look dirty, then it will do no harm to give your system a bit of TLC.

If you are using bare wire, then just cut off the end and strip a new section of insulation. That is, assuming you have enough slack to spare!

Speaker wire inside a banana plug or other type of termination should be protected and clean. That's one advantage of using these types of connectors.

But, if the connectors on the wire – or on the speaker and amplifier – are dirty, then give them a clean.

I have always used Isopropyl alcohol cleaning fluid. There are many brands that you can pick up cheaply enough.

This is perfect for cleaning all types of electrical components.

Should I Solder Connectors or Tin Speaker Wire?

I don't. Although that's partly because I'm really bad at soldering.

My take is that you don't need to, but you can if you want.

Tinning the bare ends of speaker wire can help to prevent oxidation and keep rogue copper strands in check. But it also might make it harder to get a solid connection with a binding post or screw-in plug.

Once the bare wire is tight inside the binding post or banana plug, then it shouldn't get dirty anyway.

A soldered connection for a plug might give you less chance of oxidation and a more reliable connection. But you need to be sure your soldering skills are up to the job, or you might make it worse.

Some people do. I would say most people don't.

Many banana plugs will have a screw-in connection which will work just fine. Just go with what you are comfortable with. It's not worth losing sleep over.

Conclusion

So, there you were, thinking that buying some speaker wire for your system was the easy bit!

Not so fast. As with most things in the world of home theater, if you want to dig into the detail there are plenty of fun things to learn.

As you now know, there are a few things that you should understand before getting some speaker wire.

But, it's not that difficult.

First, work out how far you need to run the cable – and what the impedance of your speakers are. Then, you can purchase the correct gauge wire for your room.

It doesn't need to be more complicated than that.

If you want to go for some expensive 'audiophile' wire, then that's up to you. I'm not convinced that there is much to gain in that respect.

I would keep it simple and put that extra money towards a better amplifier or speakers. But, at the end of the day, it's your choice.

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About Home Cinema Guide

Paul started the Home Cinema Guide to help less-experienced users get the most out of today's audio-visual technology. He has worked as a sound, lighting and audio-visual engineer for around 20 years. At home, he has spent more time than is probably healthy installing, configuring, testing, de-rigging, fixing, tweaking, re-installing again (and sometimes using) various pieces of hi-fi and home cinema equipment.