Understanding the wire thickness and length requirements for your speaker system is critical to having a functional setup. Wire gauges can vary based on what a particular wire is used for. Having the wrong thickness will affect the sound quality of your speaker.
Speaker wire thickness needs to be at most 5 percent of the speaker’s rated electrical resistance. Impedance, or electrical current resistance, increases with cord length, so more powerful speakers require a thicker cord. The AWG of speaker wires is between 10 and 22, with 10 being the thickest.
Understanding Impedance
Impedance is another word for resistance in the world of speaker cables.
The term to impede, or to stop or resist, refers to the same thing when speaking about an electrical current between your amplifier and speaker. To have the highest sound quality, it is best to have as little electrical current resistance as possible when you’re connecting a wire.
To achieve this, it’s critical to understand which gauge level to use. Wire thickness affects impedance, or how smooth the sound runs through the wire, over a distance.
- The basic rule of thumb when it comes to impedance is that the thicker a wire is, the less impedance is caused.
This doesn’t necessarily mean that a thicker wire is always the best course of action, however. Higher gauge wires will work just fine for shorter setups, and having an impedance level that’s too low can negatively affect the amplifier.
Every speaker system and amplifier are rated for a certain level of impedance, or ohm.
Most amplifiers and speakers on the market today have a minimum of 4 ohms. It is not recommended to go below this impedance level without professional experience due to the risk of the amplifier’s circuit overloading. An overloaded circuit can severely damage your equipment, potentially costing you hundreds or thousands of dollars to repair/replace.
Wire Gauge Thickness and Distance
Cable thickness gets larger as the gauge number gets smaller.
For example, a 12 gauge wire is thicker than a 16 gauge wire and so on. A thicker cable allows for more electricity to pass through and has less resistance or impedance. Speaker wire is labeled under the acronym AWG (American Wire Gauge).
AWG speaker wire gauge size ranges from 10 AWG to 22 AWG, but most systems use 12, 14, or 16 AWG.
The required thickness of the wire depends on the electrical load the system requires to produce optimal sound quality. Speakers are usually rated by 4, 6, or 8 ohm, which indicates the electrical load they can safely handle, with 4 being the highest.
The AWG thickness your wire needs to be is directly correlated with the ohm load your system is optimized for and the length of the wire. The longer the wire, the thicker it needs to be to maintain the same sound quality.
| AWG | 4 ohm System | 6 ohm System | 8 ohm System |
| 10 | 100 ft | 150 ft | 200ft |
| 12 | 60ft | 90ft | 120ft |
| 14 | 40ft | 60ft | 80ft |
| 16 | 24ft | 36ft | 48ft |
| 18 | 16ft | 24ft | 32ft |
| 20 | 10ft | 15ft | 20ft |
| 22 | 6ft | 9ft | 12ft |
On the other hand, a thinner wire works just as well over shorter distances.
If you have just a few feet of distance to cover, a smaller gauge wire will do the job just fine. For example, if you have a 6-ohm system with 60 feet of distance between your amplifier and speaker at least a 14 gauge wire would be needed.
If you wanted to use the same 6-ohm system but only had nine feet to cover, a 22 gauge wire would work the exact same.
With this in mind, a larger cable will cover the needs of a smaller cable, it just has an unnecessary amount of impedance. This won’t harm your system and many find it easier to select the largest wire size and use it for all connections.
Check out this 12 Gauge speaker wire here on Amazon.
*It is important to note that leaving yourself several feet of extra wire will allow for a much easier time plugging things in and setting up. Make sure you don’t forget to calculate these extra feet into your wire gauge needs.
When to Use Thicker Speaker Wire
The 12-19 AWG range is by far the most common thicknesses that are used.
These wire gauges will likely cover the required impedance for the most common systems. Veterans of making speaker setups will usually just use one universal thickness that will cover all of their needs.
For example, a 12 gauge wire is large enough to cover up to 120ft for an ohm 8 system and will cover any smaller requirements as well. In reality, any cord that is larger than the minimum requirements of the longest wire will work well for any setup.
While getting a thicker wire to cover all of your needs is easiest, it is not the most cost-effective option because the thicker wire is more expensive and can be overkill with thick wire taking up too much space behind your setup.
A general rule of thumb when it comes to choosing your speaker wire is thicker wire (12-14) is really only needed to cover high power systems (4 ohms and above) and the cord is longer than 100ft.
So when is thinner wire needed? Thinner wire works for shorter distances just as well as thick wire and is more cost-effective. A 16 gauge wire is best used in relatively short applications, for example, if you had fifty feet to cover for a low-power 8-ohm system.
Check out this 16 gauge speaker wire here on Amazon.
When to Use Thinner Speaker Wire
Wires that are above 16 AWG are very thin and will still work well for very short length requirements. If you have a distance that is 16 feet or fewer you need to cover, 18-22 gauge wire is will work just as well as a thick wire and will cost you significantly less.
Check out this YouTube video that discusses different wire gauges.
Speaker Wires Don’t Need to Be Expensive
The speaker industry is full of companies advertising that their particular wire will make your sound system create a warmer, more clear sound and will charge significantly more for their wires. This is usually an unnecessary cost due to the simple science of impedance and speaker length.
A longer, thicker wire will produce the same sound quality at a greater length than a thinner wire will at a shorter length.
Do not waste your hard-earned money on expensive cords making wild claims that they will drastically improve your sound quality.
Speaker wire sizing and requirements can be very intimidating, but as long as you understand your system’s power, and the level of impedance needed for length, you should be just fine.
What level should I set my Speakers to?
I have written an article on this subject. You can read it here.