Speaker wire, also known as loudspeaker wire, is primarily used for connecting amplifiers to main speakers and surround speakers in home theater systems. It connects the amplifier to the speakers. Compared to video and audio cables, it carries a larger current signal, and due to the high signal amplitude, speaker wires often do not have shielding.
For this type of cable, the key is to reduce its resistance. Since modern amplifiers have very low output resistance, the requirements for speaker wire have also increased, such as using wires with larger cross-sectional areas or multi-stranded twisted wires.
1. Differences in Speaker Wire Materials
In audio equipment, there are specific cables designed for connecting amplifiers and speakers. Speaker wire mainly transmits real power signals, so it is required to have excellent conductivity and high-quality transmission capabilities.
On the market, speaker wires are divided into copper-clad aluminum and oxygen-free copper. While copper-clad aluminum is still in use, it has significant line loss, so we need to be cautious when selecting wires.
Currently, oxygen-free copper speaker wire is more mainstream, with lower resistance. This is commonly referred to as gold-silver wire.
Speaker gold-silver wire typically does not have shielding because the current signals flowing through it are greater than those in audio and video cables, resulting in a large signal amplitude.
For gold-silver wire, the most important factor is to reduce the wire's resistance, as the impedance when the amplifier outputs is very low.
The reason for the different materials on either side of gold-silver wire is to distinguish between the oxygen-free copper and tinned copper, as well as combinations of copper-clad aluminum and tinned copper, primarily to clarify the ± polarity.
Gold-silver wire is mainly used in various types of speakers, PA projects, home theater connections, and public space broadcasting systems. Oxygen-free copper provides better audio transmission performance compared to ordinary cables.
2. The Difference Between Speaker Cables and Audio Cables
The audio cable directly transmits power signals. Due to the high current, the copper core of the cable is usually thicker. To ensure high-frequency transmission and reduce resistance loss, most cables are made of silver-plated, gold-plated, or oxygen-free copper.
Audio cables transmit low-power, low-current signals, and due to their high impedance, they are easily susceptible to interference. Therefore, they are generally shielded cables, and the wires are relatively thin.
Audio cables typically have shielding, while speaker wires often do not. The key is to reduce resistance. Among speaker wires, the more expensive option is oxygen-free copper speaker wire, which is characterized by good conductivity and low resistivity.
Audio cables generally come in two types: copper-plated audio cables and oxygen-free copper audio cables. Audio cables are categorized by the number of strands, such as 100 strands, 200 strands, 300 strands, 500 strands, and 600 strands. The "strands" refer to the cores of the audio cable. For example, a 100-strand audio cable consists of 100 copper cores inside. Generally, the more strands there are, the better the performance, and naturally, the price is higher. However, for home use or standard speaker applications, choosing cables with 200 to 300 strands is usually sufficient.
III. How to Choose Speaker Cables
The power is not directly related to the number of cores in the speaker wire; it is directly related to the cross-sectional area and material of the conductor in the speaker wire.
The number of cores shouldn't be too many, but it shouldn't be too few either. Single-core cables provide sufficient strength, but they can be harsh and lack separation. Multi-core cables offer good separation, but they may lack power. Therefore, there isn't a specific recommendation for how many cores to use; it depends on your current speaker requirements. If you feel that the low frequencies are lacking power, you might opt for fewer cores. If you find that the sound lacks layering and three-dimensionality, and the audio seems muddled, then you should use multi-core cables. As for the exact number, it requires gradual adjustment on your part.
1. Recommendations for Choosing Audio Cables
For the 100W speaker, use 1 square millimeter or 100-150 strands of oxygen-free copper speaker wire.
A 200W speaker can be used with 1.5-2 square millimeter or 200-300 core oxygen-free copper speaker wire without any issues.
For 300W-500W speakers, using 2.5-3 square millimeter wire is sufficient.
If you need to conceal the speaker wires, it is best to use PVC conduit for installation.
The difference between 200 cores and 300 cores is not significant. If the wiring distance is relatively long, it is advisable to use thicker speaker wire to avoid excessive power loss along the line.
2. What does it mean for an audio cable to have 100 cores?
Before understanding how to calculate the square of speaker wire, let's first take a look at the number of conductors in speaker wire.
The audio cable is dual-core, and the 100-core audio cable comes in two scenarios.
The first type is: single-core 100 cores, so for dual-core it would be 100*2.
The second type is: dual-core 100 cores, single-core 50 cores. That is, 50*2.
So what is the situation with the 100-core audio cable?
This refers to a single 100-core cable. Whether it can be used depends on your distance and the rated power of the speaker. The longer the distance, the thicker the wire gauge should be. Generally, a 100-core speaker cable is suitable for distances of around 5 meters, while a 300-core speaker cable is appropriate for distances of 20-40 meters. Additionally, the power of the speaker should not be too high; the greater the power, the thicker the wire gauge needed. For ordinary full-range speakers, a rated power of up to 400 watts can be transmitted within a distance of 40 meters. If the power or distance exceeds these limits, a thicker wire gauge should be used.
If used for public broadcasting, it doesn't matter (70~110V constant voltage speakers, sound systems). Generally, a 300-core cable can be used within 80 meters.
Many merchants now combine two wires and count them as a certain number of cores, which confuses the concept. They aim to sell a 100-core*2 wire at the price of a 50-core*2 wire, and many users do not understand this. A true 100-core wire consists of a single wire with 100 copper strands, which is the first type, meaning that each wire contains 100 cores, or 100*2 parallel wires.
Having understood this, the Low Voltage Master will now calculate the square with everyone.
3. How to convert the speaker wire to square millimeters?
For 100 strands (core), the diameter of audio cables on the market is generally around 0.1mm. How do you calculate its square?
The formula for the cross-sectional area of a single core: π*R² = which is 3.14 times the square of the radius.
Just multiply by the number of cores.
The formula for converting speaker wire gauge is:
The conversion formula is: Area = 3.14 * (Copper wire diameter / 2)² * Number of single strands of gold and silver wire.
For 100 speaker wires, the copper wire has a diameter of 0.1mm, so its cross-sectional area is:
Area = 3.14 * (0.1/2)² * 100 ≈ 0.8mm²
Thus, the cross-sectional area for 100 strands of gold and silver wire is 0.8mm².