Why Speaker and Instrument Cables Aren’t Interchangeable

Introduction

Sometimes, we just want to plug in speaker and instrument cables interchangeably; in the end, they’re all cables, right? All that talk of shielding, impedance, metal types used, and so on can get tedious and confusing, especially for rookies! It’s good that manufacturers usually label these cables correctly because using an instrument cable for a speaker can be dangerous!

You might have, in the past, wondered why a cable well-suited for connecting an amp to a speaker isn’t well-suited for connecting a guitar to a mixer. Generally, instrument cables are usually smaller gauge (GA) wires with shielding, while speaker cables are large GA, unshielded wires.

In this blog, we will explore in depth why these two types of cables are not interchangeable. We will cover the following topics:

· Understanding Shielding in Cables

· Why Instrument Cables Shouldn't Be Used as Speaker Cables

· Wire Gauge: Smaller GA vs. Larger GA

· Applications of AWG in Audio and Video

· Conclusion

Understanding Shielding in Cables

What is Shielding?

Shielding is the act of insulating one or more insulated (coated) conductors/wires that share a common unenclosed layer. Coating/shielding aims to prevent the switching or interference of electronic signals between nearby cables. Shielding reduces crosstalk, which explains why instrument cables are shielded. Crosstalk occurs when a signal transmitted on one cable creates an undesired effect on another nearby cable. This interference can cause noise and signal degradation, which is particularly problematic in audio applications.

Why Shielding is Essential for Instrument Cables

Shielding in instrument cables is mainly to prevent interference; it also makes cables work with weak signals (high impedance) coming from instruments (like a guitar). These weak signals are susceptible to picking up noise from other electronic devices and cables in their vicinity. The shield acts as a barrier, protecting the signal from external noise sources.

In contrast, speaker cables handle the amplified (i.e., low impedance) electronic signals that come from the amp. These signals are much stronger and less prone to picking up external noise. As a result, speaker cables do not need shielding.

Why Instrument Cables Shouldn't Be Used as Speaker Cables

Electrical Buzzing and Damage

Using an unshielded cable (speaker cable) for an instrument will likely cause lots of electrical buzzing. The buzzing probably won’t hurt anything, but using an instrument cable (shielded cable) to connect your amp to your speaker can BLOW UP your amp!

Instrument cables are not designed to handle the high power levels that speaker cables carry. When used inappropriately, the excessive power can cause the cable to overheat, potentially leading to a fire hazard. Moreover, the higher resistance of instrument cables can strain the amplifier, causing it to fail.

Signal Strength and Compatibility

The audio signals coming from instruments are relatively weak compared to the audio signals received by your speaker. You risk damaging a device when you use a cable designed to accommodate the wrong signals. Running a weak current through a cable intended for massive signals won’t hurt anything, although you might hear some noise. However, doing it the other way round will likely hurt your instrument.

Using an instrument cable as a speaker cable can also result in a significant loss of audio quality. The high resistance and inadequate power handling capacity can lead to signal degradation, resulting in poor sound performance.

Wire Gauge: Smaller GA vs. Larger GA

Understanding Wire Gauges

Earlier, we talked about instrument cables being smaller gauge (GA) wires with shielding, while speaker cables are larger GA, unshielded cables. You might have come across wires labeled 12GA, 14GA, or 18GA, in stores. Wire thickness is represented by its American Wire GA (AWG) number, and a higher number indicates thinner wire. I.e., the smaller the number, the thicker it is.

The thickness of a wire is crucial because it determines how much electrical current the wire can safely carry. Thicker wires (lower AWG numbers) can handle more current without overheating. This is particularly important for speaker cables, which carry significant amounts of power from the amplifier to the speakers.

The Importance of AWG

Wire thickness is determined by the American Wire Gauge (AWG) number. AWG is the standard used for determining the cross-section of an electrical wire with the aid of a gauge. A lower AWG number indicates a thicker wire, while higher numbers indicate thinner wires. AWG has been the standard used by users for determining current-carrying ratings since 1857.

With AWG, a stranded wire usually takes up more space than the solid wires because you can only measure them by adding up a cross-sectional area of the wire strands. In between these strands are what is referred to as air pockets, thus the reason for the larger space in the stranded configuration.

AWG usually measures electric wires, specifies the diameter of the wire, and determines their electrical resistance. With the help of AWG, you can determine the capacity of different types of nonferrous wires such as copper, aluminum, and copper-clad aluminum. You can also determine the diameters of other wires like solid, round, electricity conducting wires, etc.

Applications of AWG in Audio and Video

Speaker Circuits

Wire gauge is a very critical aspect of any cable, including speaker circuits. The frequencies of speakers vary significantly, from very high, nominal, or very low, and the level of power to be transferred by the cable depends on the frequency level. The lower the speaker impedance, the higher the energy absorbed by the cable, and the higher the impedance, the higher the power delivered to the speaker. As a result, excessively high resistance in any speaker will lead to the loss of high-frequency signals, which will cause the speaker to sound differently. Knowing the right wire gauge will help prevent poor-sounding speakers due to excessive speaker impedance.

Audio Interconnects

Generally, audio interconnects circuits operate with high impedance. AWG is necessary in this case, as it would determine the capacitance of cable. Audio interconnects, unlike speaker circuits, require less AWG, which means the AWG of the center conductor has to be reduced for the efficiency of the signal quality.

Parallel Digital Video and Analog Video Interconnects

Parallel digital videos also require less resistance, as high resistance could reduce the performance level in some critical aspects, such as capacitance, return loss, crosstalk, or skew. Analog video interconnects, on the other hand, require high frequency, and consequently, an increase in resistance of the center conductor.

Uniformity in Installations

Lastly, but equally important, is the need for professionals to install a uniformly rated wire in any circuit, whether for power, home stereo speakers, or car stereo. AWG ensures that even if you order online, the AWG rating will match the existing wires in terms of quality and size. This way, you can trust your purchase and rest assured that it will serve your specific needs.

Conclusion

AWG is related to resistance, and thicker wires have less resistance and can transport higher voltage. Thus, when using small gauge sizes, they should be combined with higher AWG numbers due to their flexibility. In summary, understanding the differences between speaker cables and instrument cables, along with the significance of wire gauges, is crucial for anyone dealing with audio equipment. Proper cable selection ensures the safety and longevity of your devices, providing the best possible sound quality.