Learn About Speaker Wires
“Oh, right. The speaker wire.”
It’s easy to forget that speakers, amplifiers and receivers don’t come with speaker wires – until you’ve got everything positioned just right and realize that you’re not going to be able to actually sit back and enjoy your new A/V setup or home theater without buying wire to hook up the speakers.
Let’s be honest. Any copper wire you have hanging around the house will do at least a passable job of carrying audio from your source to your speakers. But you’ve probably laid out a ton of money on the right components – so it only makes sense to figure out what type of speaker wires will let you get the most from your sound system.
Why Speaker Wires Are So Important
You obviously know the purpose of speaker wires: they carry electrical current from audio components to speakers, in order to produce sound. Theoretically, any wires could do that job, in the same way that you could use a drinking straw or a large metal pipe to carry water from a faucet to your flowers – but you’ll get the best results with a flexible garden hose that’s the proper size and made from the proper materials. In your home theater you’re transporting current and not water, but the same concerns come into play; you want to choose speaker wires that are the right size and made from the right materials, in order to produce the best results.
When speaker wires aren’t chosen properly, the speakers don’t get all of the electrical information they need to faithfully duplicate the audio from source material. The sound quality may be “good,” but with all of the money you spent on your audio system you don’t want “good,” you want great.
Here’s what you need to know to get it.
Characteristics of Speaker Wires
There are three electrical characteristics of speaker wires which have an effect on performance: capacitance, inductance and resistance. They are all interrelated and the most important of the three is resistance, which defines how easy or difficult it is for current to pass through the wire to the speaker. As you’d probably guess, the less resistance there is in the wire, the better the speaker’s performance will be.
Several factors combine to determine a speaker wire’s resistance. The first is conductivity, or to say it another way, how well the wire’s base metal conducts electricity. Almost all quality speaker wire is manufactured from either pure copper or copper-clad aluminum (aluminum with a thin layer of copper surrounding it, known as CCA), because copper is an excellent conductor and aluminum is a very good one. Pure copper is the best choice, but the combination of copper and less-expensive aluminum lowers the overall cost. The conductivity of CCA is about 70% that of pure copper; however, most listeners can’t tell the difference between the two. You’ll also see aluminum speaker wire, which is even less expensive and has about 60% the conductivity of pure copper.
The other two factors to consider are the length and thickness of speaker wires. The longer the wires are, the more resistance they present (since current has to travel further to reach the speakers). Conversely, the thicker they are, the lower the resistance (because there’s more of a cross-section through which the electricity can travel). That leads to two important conclusions: you shouldn’t use longer speaker wires than you need, and thicker speaker cables are generally a better choice than thinner ones. “Thicker” is an even better choice when using aluminum speaker wires, because the lower resistance of thick cable will compensate for aluminum’s lesser conductivity.
We won’t waste your time discussing length, since we’re sure you know how to use a ruler. However, you do need to know more about thickness because the way it’s measured is counter-intuitive.
Wire thickness is measured by “gauge” and sometimes referred to as AWG (American Wire Gauge). Here’s the somewhat-confusing part: the lower the number, the thicker the wire. Speaker wire is commonly seen between 12 and 18AWG, with 12AWG the thickest and 18AWG the thinnest. As you’d expect, the thicker gauges are also more expensive and a little harder to work with.
The AWG scale is logarithmic (if you remember your high school or college math, you might recall what that means) so you need formulas if you want to calculate relative resistance or the ideal gauge for your speaker installation. One often-cited formula from speaker wire expert Roger Russell is that “wire thickness should be selected so that the total speaker wire resistance is no more than 5% of the speaker's lowest impedance.”
The easier way to figure out what gauge of wire to buy is to use simple rules of thumb. If you’re running speaker wire over a long distance (50 feet or more) or if you have low-impedance speakers (such as 4 ohms), go with thicker 12 or 14 AWG speaker wire. Shorter runs, or ones connecting to 8 ohm speakers, don’t require thick cable; 16 or even 18AWG is more than sufficient. Even audiophiles can’t agree on the pure copper vs. CCA debate, so go with pure copper if you can afford it and want the highest-quality audio, but don’t worry if you choose CCA.
Oh – and one other answer to a question people often ask: speaker wires don’t care if your audio is standard analog or if you have the very latest high-definition digital surround sound system. They’ll work with both analog and digital signals just fine, as long as you buy high-quality cables.
Other Considerations When Buying Speaker Wires
Other choices you’ll have to make when buying speaker wires are logistical ones based on your specific needs.
For example, you can choose two-wire or four-wire speaker cables. Two conductors are all you need to connect to most speakers, but four conductors can come in handy if you’re running cable to an in-wall volume control, or if you want to use just one long run of speaker cable with two of the wires attaching to a closer speaker and the other two continuing on to a speaker that’s further away.
Most speaker wire has a durable PVC outer jacket suitable for everyday wear and tear, but you can also buy speaker cable with jackets that are rated to be run inside walls and ceilings, or run outdoors. You’ll usually see jackets in white, black or clear colors, offering a choice between traditional or “high-tech” looks. Some speaker wires are pre-terminated with connectors like banana plugs, while others terminate in bare wires which are the most flexible choice.
And if you purchase speaker wire from a reputable company like Cmple, you won’t have to worry about the little things that make life easy like color-coding or easy-to-read polarity (+/-) indicators, since any manufacturer whose products are well-made will include those touches automatically.
Speaker wire may seem like a simple matter, and it is – if you deal with a company that produces quality cables, and if you understand the gauge, length and type of conductor that you’re looking for. It’s only when you grab a roll of speaker wire off a shelf without any forethought, or when you spend way too much for unnecessary, overpriced “Giant” cables, that you might run into problems or regrets.