Audio accessories like cables and speaker wire are some of the most overpriced and hyped things you can buy.
Should you spend a lot of money on a “magical” speaker wire or audio cable? Does it make a difference in the sound quality of your home or car audio system?
I’ll tell you this and more in clear & simple terms. Read on!
- Quick answers: Does speaker wire affect sound quality?
- The science of speaker wire and sound quality
- What is in speaker wire?
- Does splicing affect sound quality?
- Does the length of speaker wire affect the sound?
- Copper-clad aluminum vs copper speaker wire quality differences
- Cases where speaker sound response, volume, or quality can be affected
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 cable (like RCA cables), video cables, and even computer & data cables.
It’s not limited to home loudspeaker or video use, either – there’s been plenty of it in the car stereo world as well.
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 esoteric, fancy technical advantage. The problem is that there’s no scientific test data to back it up. Most of the time it’s just marketing for higher profits.
In fact, when it comes to electronics, audio accessories like RCA patch cable, headphone cables, and speaker cable 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 in 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 others have a much more significant impact on sound quality – 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 cables (like individually insulated conductors) can impact sound – but they’re not speaker wire.
- The electrical conductor phenomenon known as the 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. The tests are almost always severely 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 the people in it having different levels of hearing.
- The gauge you need depends on the power delivered from your amp or stereo and the length.
- Thicker speaker wire has lower resistance, capacitance, and inductance when compared to thin wire as it has a larger cross-sectional area (more conductance/less resistance).
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. However, it’s so insignificant it can be difficult to measure it with even very expensive and accurate test instruments.
You can think of speaker wire, like other electrical wires, 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) electrical signal like music, but extremely useful in things like speaker crossovers.
You might think, “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. Certainly 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 capacitor’s impedance (or resistance to current flow) decreases with the frequency, meaning that lower frequencies are reduced 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 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 (very similar to 18AWG or 16AWG wire) has only about 10-20pFarad capacitance per foot, giving it less than 1% loss in the audible range for a 50 foot length.
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.
Speaker wire vs electrical wire
Both electrical hookup wiring (similar to lamp cord) and those sold for speakers often use small strands of conductors and flexible insulation. In fact, in many cases, you can use either. However, you can find audio wire that’s even more flexible and has its polarity marked with red or black as well as printing. Some also have even finer copper conductors to make installation easier around tight spaces or curved areas such as cars and trucks.
Does splicing affect sound quality?
This diagram, like the speaker wire electrical model, shows how you can think of a speaker wire connector. Both wire conductors and connections 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 wiring by splicing, soldering, crimp connectors, or other ways doesn’t normally affect sound quality. It can’t – it’s just another path for the flow of power & and the audio signal to flow through.
However, an unusually poor connection can 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 splices when extending speaker wire. Soldering is the best, 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 important and you won’t hear the difference.
Good quality crimp connectors (left) and soldering (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)
A good option that’s affordable, simple to use, and makes a great connection is a pair of banana plug connectors if your stereo system can use them.
Does the length of speaker wire affect the sound?
It’s possible to lose sound quality a little bit by using a wire or cable length that’s excessively long or not large enough.
- A much greater speaker wire length (say 50+ feet [15.2m], especially 100ft [30m] or more) has more resistance. It can cause a small volume & power drop, especially at maximum amplifier power levels. It can also affect a parameter called the damping factor, although it’s not usually an issue.
- 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.
- It depends on the power because more power means higher amps pass through the conductors. A lower speaker impedance like 4 ohms or 2 ohms will draw more current than a higher impedance like 8 ohms for the same power.
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 speaker’s impedance. 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
|Car and home speakers up to 25 ft with average power levels (50W RMS and below)
|Longer speaker runs for car & home stereo speakers; Moderate power subwoofers (under 225W)
|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 rarely 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.
When running it a relatively short distance with low to average power (for example to a rear speaker pair in your home or car) don’t stress out over it.
Does using small speaker wire affect sound quality?
Using a thin wire won’t exactly affect sound quality – meaning you won’t hear a noticeable difference – but it 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 as you’ll see below.
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 cable go up one gauge in size.
For example, to replace 18 gauge copper speaker 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 type) leads to bad performance:
- 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 connection
- 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 connection or solder to eliminate this. Note that covering it with electrical tape isn’t enough.
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 that instrument cable you’ve got lying around, cables are often 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.