A Beginner’s Guide to PA’s- The Difference between Speaker Cables and Shielded Guitar Cables

Some people still connect the shielded guitar cable between a power amplifier and a speaker in a PA system.
In this issue, I am writing about the differences between speaker cables and instrument cables again but making this one more accessible to beginners.

■ Contents

1. Features of Speaker Cables
2. Characteristics of Shielded Guitar Cables
3. When used in the wrong way

1. Features of Speaker Cables

What is a speaker cable?

A speaker cable is used to connect a power amplifier to a speaker. It sends and receives audio signals (electrical signals) with large electric power in a low impedance.
Therefore, they are designed to pass a large current safely with little loss.

Here are some standard speaker cables.

Belden / 8470 Speaker Cable

• Number of conductors: 2
• Conductor cross section: 16AWG
• Maximum current: 18A (room temperature 30℃)
• Rated voltage: 300V

Manufacturer’s product page

Canare / 4S6 Speaker Cable

• Number of conductors: 4
  *4 conductors have the effect of suppressing emitted noise.
• Conductor cross section: 20AWG
• Withstanding voltage: 500V AC for 1 minute, no abnormality

Manufacturer’s product page

Closer Look at Speaker Cables

Speaker cables are mostly 2- or 4-conductor, with no outer conductor (in other words, the shield part). The cross-sectional area of the center conductor is often around 14-20 AWG. (The smaller the AWG number, the larger the area.) As for the maximum current, Belden 8470 is designed to withstand a fairly high current of 18A. 4-core cables can be used with a 4-pole pin assignment of +1/-1 and +2/-2 at the Speakon terminals, and they can also be used for other applications. As for the actual feel of the cables, both cables give the impression that the wiring is firm and the core wires themselves are quite sturdy.

2. Characteristics of Shielded Guitar Cables

What is a shielded guitar cable?

It is a cable used to connect an electric guitar and other musical instruments to an instrumental amplifier. It receives and transmits high-impedance, weak audio signals (electrical signals), with instruments like electric guitars. Since weak signals are easily affected by external noise, shielding (an external conductor) is used to deliver signals with superior sound quality. Shielded guitar cables are also characterized by their ingenuity in consideration of playability during performance.

Here are some standard shielded guitar cables.

Belden / 8412 Shielded Guitar Cable

• Number of conductors: 2
• Conductor cross section: 20AWG
• Outer conductors: Rayon and thin copper wire
• Maximum current: 4A (room temperature 25℃)

Manufacturer’s product page

Canare / GS4

Canare / GS6

• Number of conductors: 1
• Conductor cross section: 22AWG (GS4) 18AWG (GS6)
• Outer conductors: Conductive vinyl and OFC (Oxygen-free copper)
• Withstanding voltage: 500V AC for one minute, no abnormality

Manufacturer’s product page

Type	Model	Sales Units	Outer Diameter	Weight	Center Conductor		Insulator	Outer Conductor	Electrical Characteristics
					Cross Sec. Area (AWG) Configuration	Outer Diameter	Outer Diameter	Shield Configuration Density of Braid	Resistance of Inner Conductor	Resistance of Outer Conductor	Electrostatic Capacity
		m	mm	kg /100m	mm2 (AWG) Q’ty/mm	mm	mm	mm/Ends/Carriers (%)	Ω/100m	Ω/100m	pF/m
Sheath Color /  GS-4 : Black GS-6 : Black Red Orange Yellow Green Blue	GS-4	200	4.0	2.7	0.39 (22) 50/0.1(OFC)	0.82	1.82	Conductive Vinyl + 0.1(OFC)/6/16 (93%以上)	4.7	3.1	-
	GS-6	100 200	5.8	5.0	1.0 (18) 127/0.1(OFC)	1.3	3.0	Conductive Vinyl + 0.1(OFC)/8/16 (92%以上)	1.8	2.5	160

A Closer Look at Shielded Guitar Cables

The main difference from speaker cables is the presence of an outer conductor (what is called a shield). The presence or absence of this shield is an important factor because it sends weak signals. The conductor area is also 18-22 AWG, which means that the area is smaller than that of speaker cables = thinner wires. As for the maximum current, the Belden 8412 is 4A, so the maximum current that can flow is about 1/4 of that of speaker cables. The cables are more flexible and easier to handle than speaker cables, and are designed for playability so as not to affect performance.

3. When used in the wrong way

When a shielded guitar cable is connected between a power amplifier and a speaker

Considering the (electrical) durability of the guitar cable, it is designed to pass weak signals and is not intended to carry a large current. If the guitar cable continues to receive high power signals from the power amplifier, the power that cannot be received by the guitar cable will be converted into heat. If heat energy builds up in the guitar cable, the worst case scenario is that the cable may burn out. Therefore, speaker cables must always be used.

When a speaker cable is connected to a guitar and a guitar amplifier

Speaker cables have no problem passing weak electrical signals from the guitar. However, the guitar cable has a shield (outer conductor), while the speaker cable has no shield. Therefore, there is a risk that external noise or, conversely, noise generated by the cable may affect other equipment. After all, it is definitely advantageous to use a guitar cable in this case as well.

Meaning, it is very important to use the right cable for the right application. Appropriate use is the key to bring out the performance of each device, and I hope you will find this information useful.