CL2 vs CL3 Speaker Wire | What’s the Difference?

CL2 (Class 2) and CL3 (Class 3) speaker wires are two of the most commonly used cable types in home audio installations. CL2-rated wires are designed for residential environments, whereas CL3-rated lines are intended for commercial and industrial settings.

Quick Comparison: CL2 vs CL3

The main difference is how much voltage they can handle at once. For speaker installations, the trustworthy 150-volt threshold of CL2 is usually adequate. But if your needs require more voltage than this, you must choose the improved 300-volt capacity using a certified CL3 cable. Both cables work just fine, so don’t worry. Remember that if you want to jump from “adequate” to “outstanding,” you’ll need some strong 300 volts.

The insulation material for CL2-rated cables is typically made of PVC (Polyvinyl Chloride), while CL3-rated wires are typically made of FT-6 (Fire Retardant) rated materials. The connectors used for CL2 and CL3 rated cables also differ, with CL2 using non-metallic connectors and CL3 using metallic ones.

In terms of cost, CL2-rated cables tend to be less expensive than CL3 due to their more straightforward construction and materials. However, when it comes to safety, CL3 lines are much safer than their CL2 counterparts as they have been specifically designed for use in environments where a fire is more likely to occur.

CL2 Speaker Wire

The term “Class 2 speaker wire” is referred to as CL2 The CL2 rating on the speaker wire designates that it is only secure for low-voltage connections. Speaker wire with a CL2 rating can withstand a voltage spike of up to 150 volts and is safe to install inside a wall or ceiling. The speaker wire won’t likely burn out or catch fire within this range, especially if there are sudden power surges.

Non-Metallic Connectors

CL2 cables feature non-metallic connectors that are easier to install. It also prevents a potential fire hazard in the event of an electrical short.

Used for Residential Applications

CL2 cables are generally used for residential applications in dry locations, such as data networks, security systems, and audio/video systems. It makes them ideal for use in home theaters and other areas where a fire is less likely to occur.

Not Suitable for Aerial or Direct Burial Applications

CL2 cables do not have the same resistance to weather and moisture as other wires, so they are unsuitable for aerial or direct burial applications. It means these cables should only be used indoors in dry areas. However, they can be run through walls if the appropriate sheathing is used.


CL2 cables are also cost-effective compared to other cables, such as plenum or CAT6 cables. The materials used in their construction are generally cheaper than those found in higher-end cables, and the installation costs are lower due to the ease of installation.

Not Suitable for High-Performance Applications

Although CL2 cables are economical for data and power transmission, they could be better for high-performance gaming or streaming video applications. The maximum bandwidth of these cables is limited to 10 Mbps, and the signal strength may degrade over longer distances. For best results, use a higher-grade line for these purposes.

Limited range of applications

CL2 cables are best suited for short-range applications, such as connecting devices within a room or linking speakers in the same building. Using these cables in applications that require longer runs, such as wiring an entire office, is not recommended. The signal strength will degrade over long distances, and this could result in data loss or other performance issues.


  • Durable
  • Easy installation
  • Inexpensive
  • Widely available


  • Limited speed
  • Low signal strength over long distances
  • Not recommended for large-scale applications.

CL3 Speaker Wire

The CL3 security cable is a class 3 cable for power-limited circuits with a 300-volt rating. Some examples of typical applications are signs, intercom wiring, security, room and wall speakers, internet, and TV wall installations.

Higher Resistance to Fire Hazards

CL3 Speaker Wire is designed for use in areas where fire safety is a primary concern. The cables feature an additional layer of insulation which helps them resist the spread of fire should it occur, making them much safer than other types of wiring.

Greater Protection from Tampering or Damage

The thicker insulation of CL3 cables makes it more difficult for tampering or damage to occur, as the insulation is much broader than that found in other types of wiring. It helps ensure that your wiring system remains secure and intact over time.

Lower Installation Costs

The cost associated with installing CL3 Speaker Wire is generally lower than higher-end wiring, as it is easier and faster to install due to its thinner insulation. Compared to other types of wiring, CL3 cables have a lower resistance rating, so they consume less power to function properly. It helps reduce your energy costs over time.


CL3 Speaker Wire is compatible with both new and existing systems, making it an ideal solution for those looking to upgrade their sound system without completely replacing the wiring. You can enjoy more accurate and detailed audio reproduction thanks to CL3 cables’ wider frequency range than other types of wiring.


The insulation is solid, so it can handle the high temperatures that come with running your sound system for long periods without any degradation in performance.


CL3 Speaker Wire may be more expensive than other types of wiring, but the cost savings from its energy efficiency and durability make up for the higher initial expense.


The screw terminals make for a secure connection that can be easily modified. CL3 wiring is often sold in pre-cut lengths, making installation even more straightforward.


  • Energy Efficiency
  • Durability
  • Easy Installation
  • Pre-Cut Lengths


  • Expensive Upfront Cost

Choosing between CL2 and CL3 Speaker Wires

When it comes down to choosing between CL2 and CL3 wires, the main thing to consider is the application. If you install a residential system with relatively undisturbed wiring, then CL2 may be sufficient. However, if you are installing a commercial or industrial system with more risk of physical disturbance, then CL3 is the best option. In addition, CL3 may be necessary for meeting specific fire safety codes and regulations. Ultimately, the decision should be based on your particular needs and requirements.

No matter which type of wire you choose, it’s essential to make sure you purchase from a trusted manufacturer to rest assured that your wiring is of the highest quality. Look for certifications from UL or other independent organizations to confirm that your wiring complies with regional codes or regulations.  You can decide which type best suits your speaker needs by understanding the differences between CL2 and CL3 wire differences. CL2 wire is affordable and fantastic for general-purpose wiring, while CL3 wire is better suited for high-voltage applications requiring a higher degree of fire safety.


What does a rating of CL2 mean?

A cable with a CL2 rating has completed the necessary NEC test for a high fire resistance rating. The components of the cable and the cable itself won’t burn under a sudden surge of electricity up to 150 watts.

What’s better, CL3 or CL2?

NEC 725.2 states that CL2 provides some electric shock protection while CL3 provides a little more due to its higher voltage rating.

What is the speaker wire’s CL rating?

The CL rating identifies the cable as suitable for speaker wire or HDMI wiring, which is typical for audio and video signal types.


In conclusion, the environment and voltage difference between components should be considered when selecting wiring for any application. The CL2-rated wire is suitable for low-voltage applications, and CL3 wires are recommended for high-voltage installations. Both types of wiring offer sufficient defense against risks of electric shock, and installation should be done properly to guarantee security. For safety purposes, it is crucial to consider both the speaker wire gauge and the classification rating of the wire. Running speaker wires inside a wall or ceiling is ideal for both CL2 and CL3 speaker wires.


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