Audio accessories like cables and especially speaker wire are one of the most commonly overpriced and hyped things you can buy. But what’s the truth? Does speaker wire affect sound quality?
Should you spend a lot of money on “special” speaker wire? What do you need to know for the best sound for your car or home speaker systems?
I’ll tell you this and more in clear & simple to understand terms – along with all the facts you need. Read on!
Quick answers: Does speaker wire affect sound quality?
Audiophile & hyped-up wire & cables
One of the largest problems I’ve seen over the years is the amount of hype & exaggeration used to sell overpriced cables of all types: speaker wire, audio interconnects (like RCA cables), video cables, and even computer & data cables.
It’s not limited to home stereo & video either – there has been plenty of it in the car stereo world, too.
Fancy audio cables & wire are based on nonsense
Often claims are made by companies & audiophiles that their highly-priced cables offer better sound because of some type of technical advantage over standard wire or cables. The problem is that there’s no scientific test data to back it up. Most of the time it’s just for making a larger profit.
In fact, when it comes to electronics, audio accessories like cable and wire are one of the most profitable categories for retailers!
The science of speaker wire and sound quality
Here’s a list of reasons why you won’t notice any difference with sound quality due to speaker wire. There are a few exceptions that aren’t typical which I’ll explain later.
Speaker wire sound quality facts:
- While it’s true that many electrical components & conductors do have capacitance and inductance that can affect the sound, the speaker wire has very little. Far less than what is needed to have a real impact on sound quality & the frequency response of a speaker system.
- Things like speaker performance, voice coil inductance, speaker crossovers, and more have a much more significant impact on the sound quality of a system – hundreds of times larger, in fact.
- Speaker wires are made up of a bundle of thin conductors that touch each other which keeps capacitance and inductance to a level so small it’s negligible for audio. Other types of cable (like individually insulated conductors) can have an impact on sound – but they’re not speaker wire.
- The electrical conductor phenomenon known as skin effect doesn’t apply to the audio frequency range. It’s not a concern until dealing with much higher frequencies (megahertz and higher ranges). Audio frequencies span about 20Hz to 20kHz in range.
- While it’s true that blind listening tests have been done to try and “prove” that special audio wires or cables sound better to people, they’re never able to prove it. In fact, the tests are almost always badly flawed and have no hard scientific audio test data to back them up. To make matters worse, the placebo effect has an impact on the test along with people have different levels of hearing.
Speaker wire electrical resistance, capacitance, and inductance explained
A diagram showing a model of how you can think of speaker wire or other conductors. The wire has a very small amount of resistance, inductance, and capacitance in it.
You can think of speaker wire – much like other electrical conductors, as being made up of a resistor, an inductor, and a capacitor, as nearly all conductors have at least a tiny bit of each. Resistors oppose the flow of electrical current and cause some voltage to be lost.
Capacitors and inductors are sort of like resistors but their “resistance” (called impedance in this case) changes with frequency. Because of it, they’re bad to have in wires that carry an alternating current (AC) signal like music, but extremely useful in things like speaker crossovers.
You might be thinking, “If speaker wire has some inductance and capacitance, wouldn’t that hurt the sound?”
The answer, in this case, is no.
That’s because unlike speaker crossovers where we use large values of capacitors and inductors to filter out or block certain sound ranges to speakers, speaker wire has an incredibly tiny amount. Not enough to have any real effect in most cases.
For example, we could use a capacitor in line with a tweeter to block distorting & damaging bass from reaching it. That’s possible because the impedance (or resistance to electrical current flow) decreases with the frequency, meaning that lower frequencies get reduced a lot and effectively filtered out.
Even basic speaker wire is good!
In the case of speaker wire, if the capacitance were a high value it would be possible for higher frequencies that reach the speaker to be greatly reduced & cause a poor sound quality.
Likewise, if the inductance were high enough to matter it could affect sound quality too. As I mentioned before, however, speaker wire has very low values of each. Ordinary lamp power wire (extremely similar to 18AWG or 16AWG wire) has only about 10-20pFarad capacitance per foot, give less than 1% loss in the audible range for a 50 foot length.
(For comparison, a picoFarad is .000 000 000 001, or a billionth of a Farad unit of capacitance. Capacitors used in audio speaker systems are around a few hundredths of a Farad.)
What is in speaker wire?
Speaker wire is made up of fine strands of wire, usually copper or copper-clad aluminum (CCA), that are bundled together and electrically separated from each other inside flexible insulation. Other kinds exist too, like those that are also bundled with a thin shield or other special features.
The insulation usually has a thin section in the middle which can be torn easily for separating the wires when stripping it, connecting it, and so on. Most of the time one wire is marked with a positive indicator of some kind.
Does splicing affect sound quality?
This diagram, like the speaker wire electrical model, shows how you can think of a speaker wire connector. Both the wire and the connector do have some resistance, although a tiny amount that’s negligible when used correctly. Sound quality isn’t a problem unless there’s an unusually bad connection.
Adding a connector to speaker wire by splicing, either by soldering, crimp connectors, or other ways doesn’t normally affect sound quality. It can’t – it’s just another electrical path for the electrical current & audio signal to flow through.
However, it is possible for an unusually poor connection to have a bad enough resistance that the speaker could have noticeably less volume & power loss. That’s because when a very bad connection causes a high amount of resistance to the flow of current, it also causes a large voltage drop across it, too.
That means less power is available to the speaker than normally would be at the same volume setting. It’s a waste of power.
To avoid this:
- Always use a high-quality connection for speaker wire splices. Soldering is the best of all, but good quality crimp connectors are excellent too.
- Wire connection strips (wire terminal barrier strips) with clean nickel or other plated metal contacts are suitable as well for speaker systems.
- Gold plating is not very important and won’t make a large difference in practical use.
Good quality crimp connectors (left) and solder (right) are great choices for speaker wire.
The most important thing is to make a tight & clean connection with great wire-to-wire contact.
In some cases like marine & boat use, connectors can corrode & galvanize, causing other issues that do limit sound quality. That’s much less common, however. (In that case, using an anti-corrosion liquid or spray can keep the wire from getting to that point)
Does the length of speaker wire affect the sound?
It’s definitely possible to lose speaker sound quality a little bit by using an excessively long wire that’s not large enough.
- Very long lengths of speaker wire (say 50+ ft in length, especially 100ft or more) have more resistance and will cause a small volume & power drop especially at maximum amplifier power levels.
- Very long lengths of wire will have more capacitance that can slightly affect the frequency response at the speaker. It depends on the particular wire.
Unfortunately, even if you’re technically inclined, almost no speaker wire makers offer any technical specs to help you figure out what you can expect for very long lengths. We can, however, use the American Wire Gauge (AWG) standard to know the resistance per foot for most stranded wire.
How long can you run speaker wire without impacting quality?
The length depends on a few things & the AWG size (wire gauge) you’re using. There are a few things that make a big difference:
- The impedance (Ohms rating) of your speakers. This is usually 6-8 Ohms for home stereo speakers and 4 or sometimes 2 for car audio.
- Amplifier power level you’ll use.
Here’s a basic wire size & length chart to help.
Simplified speaker wire size & length table
|Wire Size||Recommended For|
|18 Ga.||Car and home speakers up to 25 ft with average power levels (50W RMS and below)|
|16 Ga.||Longer speaker runs for car & home stereo speakers; Moderate power subwoofers (under 225W)|
|14 Ga.||Long (100ft+) speaker runs or higher power applications such as high-power 2 or 4 ohm subwoofers.|
This does make a few assumptions, though: most people almost never use their amplifier & speakers at maximum power & volume, so you’re generally fine with the recommendations listed here.
Also, most people do not run extra pairs of speakers in parallel on the same wire which would require wire 2 gauges bigger due to twice the power (and electrical current) being supplied on the same wire.
Does using small speaker wire affect sound quality?
Using a smaller speaker wire than you need won’t exactly affect sound quality, but instead can cause you to waste power and lose speaker volume. Typically, most people need about 18AWG wire for speaker systems up to 50W for 4 ohm speakers & about 100W for 8 ohm speakers in relatively short distances (25ft or less).
One thing to bear in mind is that you can’t use copper clad aluminum (CCA) wire for the same power levels as you can copper wire.
Copper-clad aluminum vs copper speaker wire quality differences
Copper clad aluminum (CCA) wire has, in the last few years, become more and more common as the price of copper wiring has gone up. It’s one of those “little things” you might not know when buying that companies aren’t telling you.
Unlike pure copper wire, copper-clad aluminum uses an aluminum wire core with a thin copper plating. From the outside, it misleadingly looks the same because of the plating.
Aluminum offers a lighter weight and lower cost than copper, so it’s at first glance it may seem like a great way to replace more expensive copper wiring. However, there’s an important difference that wire makers often won’t tell you!
How good is copper-covered aluminum speaker wire?
The good news is that CCA wire has the same sound quality as copper wire, meaning it’s fine for great sound. The problem is that aluminum isn’t as good of an electrical conductor as copper.
Aluminum has only 61% of the conductivity of copper (in other words, it has 39% more resistance) meaning it will take larger aluminum wires to get the same wire quality.
What to know before buying CCA speaker wire
In most cases like average listening & typical power levels, it’s not really a problem in day-to-day use. However, if you’re going to drive speakers at higher power levels or want the absolute best for your money, you’ll need to be sure to look for packaging that clearly states 100% pure copper.
Otherwise, copper-clad aluminum will work just as well if you follow this rule: when buying CCA speaker wire, to get the same quality as true copper wire go up one gauge in size.
For example, to replace 18 gauge copper wire use a 16 gauge CCA wire.
Cases where speaker sound response, volume, or quality can be affected
For best results, do not coil up excess lengths of speaker wire. Keep the free wire straight & curved instead. Coiled wire can act as an inductor and potentially affect the sound in some cases. (An inductor is a coil of wire that builds magnetic fields)
There are some cases where using wire the wrong way (or using the wrong kind of wire) lead to bad sound quality:
- Using non-standard wire or cable as speaker wire
- Winding long lengths of wire into a loop, creating a coil (creating an inductor basically)
- Breaks or cuts in speaker wire that cause problems with power flow
- Poor connections like twisting wire together instead of using a proper connector or solder
- Heavily oxidized wire
- Loosely connected speaker box posts or terminals
To avoid nicking the wire inside, avoid using a razor or utility knife to strip wires. Use a stripper or other tool instead.
Exposed copper wire can oxidize badly over time and cause a very poor connection, especially after being exposed to moisture and especially other air outdoors. Be sure to check and cut & re-strip if necessary or use a nice clean connector or solder to eliminate this.
Speaker wire terminals in speaker boxes can become loose and get hot once the connection is bad enough, causing a lot of power to be lost and give poor sound. It’s a great idea to check and tighten or replace terminals if you’re having sound quality issues.
Even though you may be tempted to save money by reusing some extra wire or cable you’ve got lying around, some times of cables are bad choices for speaker wire. Coaxial cable, for example, can have higher capacitance and cause sound quality problems.
Microphone and network cables usually have much smaller conductors that can’t carry the power you need for speakers, as well as being more susceptible to break if they’re solid conductors.
More speaker wire articles
I’ve got more helpful articles related to speaker wire, too:
- A detailed guide about what size speaker wire you need including speaker wire power chart
- Ran out of enough wire? Here’s how to extend & lengthen speaker wire the right way.
Feel free to leave any comments or questions below – I’d love to hear from you!