What’s the Difference Between Series Wiring and Parallel Wiring?

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What’s the Difference Between Series Wiring and Parallel Wiring?

Running wire for a car audio or home entertainment system can get confusing. It is important to keep in mind some wiring basics when starting a rewiring project. The two most common types of wiring are series wiring and parallel wiring. Each has its own best use, so shoppers should know the ins and outs of both types in order to make the correct decisions when choosing the right wiring solution. This is especially important when wiring for a speaker system in a car where the process may involve removing many panels and working in small places. Deciding on the wiring system before beginning the project can save the buyer time and trouble.

When searching for wiring, buyers should research available options before making a purchase and learn about the different gauges of wiring, because each component might require a different gauge. It is also important to know which situations are best for series or parallel wiring.

History of Wiring

The earliest form of speaker wire used was stranded copper wiring insulated by cloth tape, rubber, or wax paper. This type of wiring was fine for home applications. However, for mobile applications, lamp cord twisted in pairs was used. The ends of the cables were soldered to hold them in place. The 1920s and 1930s saw the introduction of 0.25-inch tip-sleeve jacks as a more convenient type of termination than soldering. More modern speaker wire, commonly known as zip cord, is still made from copper, just like older wire.

Understand Series and Parallel Wiring

Choosing the correct method of wiring and using the right stereo wire for the task at hand leads to a more effective outcome. In this case, it results in better sound quality from the vehicle audio system. When deciding on whether to use series or parallel wiring, keep the following things in mind, and when it comes to wiring, make sure to consider resistance first and foremost. The greater the load placed upon a speaker system, the more power is required to make it function properly.

Half of a speaker’s efficiency is lost to heat energy. It is important to keep in mind that more speakers included in the sound system means that the more heat will be generated. Also, a larger load creates more distortion, affecting overall audio quality. The sections below detail series and parallel wiring, and when it is best to use each.

The Difference Between Series Wiring and Parallel Wiring

Series wiring and parallel wiring essentially achieve the same result but in different ways. Basically, choosing between the two methods of wiring boils down to what a user wants to do with the chosen wiring method. In essence, serial wiring raises the impedance level delivered to the amplifier, while parallel wiring lowers the impedance.The list below describes the key differences between serial wiring and parallel wiring.

Series Wiring

Electrical circuits are arranged in a series, and resistors are arranged in a chain. If one circuit is taken out of the series, the whole series will not work and power will not get to the component. For example, say that there are four cells in a row, but one is out. The result of this is that electricity will not flow, because the electricity flows from one circuit to the next. If one of the circuits in the series is removed, then the current cannot flow to any of the other circuits. In an audio system, having more speakers present will increase the level of impedance.

For batteries, the series arrangement means that each cell in the battery is responsible for part of the voltage, and that all of the cells together make up the total voltage in the battery. For example, a 12v battery contains 6 cells in a connected circuit, and each cell has 2v each. Connecting two 12v batteries in a series will then result in 24v of energy.


Parallel Wiring

Each individual circuit can operate independently of any other circuit in the series due to the way the wiring is installed. A parallel circuit begins with a hot and neutral wire connected to the circuit. The other circuits in the series are connected to each other, neutral wire to neutral wire, and hot wire to hot wire. Regardless of whether a single circuit is broken or nonfunctional, the working circuits in a parallel circuit keep functioning. In audio terms, the wiring is done in such a way that all speakers operate on the same voltage when playing sound.

For batteries, the parallel arrangement means that the total voltage of the battery is equal to the voltage of each cell, rather than of each cell added together. Parallel-connected batteries are now rarely used, since series batteries are favorable in terms of capacity.


Stereo wiring works under the principle of using an electric current to carry the audio signal from the receiver or amplifier to the speakers. In order to successfully wire an audio system, the minimum and maximum impedance levels of the amplifier need to be determined, which are usually located on a label on the bottom of the amplifier. This allows whoever installs the system, and more specifically the wiring, to know which wiring method best suits their needs. Using a car audio system as an example, we will describe in the sections below the different wiring types and when it is best to use them.

When it Is Best to Use Serial Wiring

The more speakers that shoppers have connected through series wiring, the higher the load that the wiring must carry. Shoppers can improve this impedance through the use of an amplifier, with 4 ohms usually equating two subwoofers to one amplifier or one speaker per channel. But users should be careful to not have too large of a load in ohms. One of the drawbacks of low impedance is that the more power pushed through the amplifier, the more distortion and heat is created. This heat can shorten the life of the amplifier as well.

When using serial wiring for a car audio system, it is best to keep the size of the system small because the higher the impedance created by using more speakers, the lower the speaker output created when it is connected to an amplifier. When trying to determine if serial wiring is the way to go, shoppers should first add up the impedance levels of the speakers to be used. In the case of a two-channel amplifier, as long as the impedance level of the speakers used is within the amplifier's limits, then any number of speakers could be used. If this sum is greater than the impedance range of the amplifier channel, then shoppers could potentially still use the parallel wiring method found in the next section to wire their sound system.

When it Is Best to Use Parallel Wiring

Parallel wiring is best used for a larger audio system. Since all of the speakers are wired to operate on the same voltage level, the current sent through the wiring does not have to be divided among the various speakers. This allows for the utilization of more speakers in the audio system.

However, if the sum of the impedance level of the speakers exceeded the limits of only one channel of the amplifier, then parallel wiring becomes the preferred method. Parallel wiring allows for two speakers, such as subwoofers for example, to be safely connected to one channel of an amp. This is accomplished by first making sure that the quotient of the two speakers does not exceed the limits of the amplifier. Do this by adding the impedance levels of the two speakers together. Next, multiply the same base impedance levels and divide that total by the first sum. If this number falls within the impedance limits of the amplifier, then the speakers can be connected using parallel wiring.

Lengths of Speaker Wire

The shorter a wire is, the closer it approaches the ideal wire, which has no resistance, capacitance, or inductance (also known as the three components of a wire). The list below includes some wire terms and their definitions.




A combination of three factors that help determine the load a wire carries. Usually this ranges from 4 ohms to 16 ohms.


The amount of resistance to the electric power sent through a wire. Measured in ohms.


The capacity of a wire to lose energy between two conductors, such as a speaker and an amplifier. The higher the capacitance level of a wire, the less signal that is lost.


The resistance of the wiring to changes in the signal. Generally, the quicker the change, the higher the resistance.


Standard Wire Gauge


American Wire Gauge

Knowing what factors determine the audio capabilities of a particular wire type and gauge allows shoppers to pick the best gauge of wire for their particular needs.

Max Wire Length

As indicated in the section above, the shorter a wire, the closer it comes to the ideal wire. In most cases, though, length is not a matter of preference. It is determined by the needs of the audio system being wired. The thicker the wire gauge, the more power it can safely handle. Listed below are the different gauges of speaker wire available and the recommended lengths based on an impedance rate of 5 percent.

Wire Size

2 ohm Load

4 ohm Load

6 ohm Load

8 ohm Load

22 AWG

3 feet

6 feet

9 feet

12 feet

20 AWG

5 feet

10 feet

15 feet

20 feet

18 AWG

8 feet

16 feet

24 feet

32 feet

16 AWG

12 feet

24 feet

36 feet

48 feet

14 AWG

20 feet

40 feet

60 feet

80 feet

12 AWG

30 feet

60 feet

90 feet

120 feet

10 AWG

50 feet

100 feet

150 feet

200 feet

Shoppers should have an idea of how much stereo wire they need for an audio project. This allows them to buy the proper gauge and overall length of stereo wire dependent on the system requirements. With these facts in mind, the buyer can then find the shortest possible wire for the project.

Wire Materials

Stereo wiring can also be made of a variety of metals. The three most common metals used in the making of stereo wires and terminators include copper wires, silver wires, and gold terminators:

Wire Material


Copper Wiring

The universal metal used in the making of stereo wires. Its low resistance and cost-effective price make it a top pick over other metals.

Silver Wiring

Silver, while having a lower resistance than copper, is more expensive than copper wiring. Its lower resistance allows silver wiring to be thinner than copper.

Gold Terminators

Gold has more resistance than either silver or copper. Its preferred use in audio applications is as a plating material for wire terminations due to its resistance to tarnishing and corrosion.

While copper is the most common wiring material, shoppers can also consider silver wiring for special applications or gold terminators for their non-corroding properties.

Find Stereo Wire on eBay

Once shoppers know what type of stereo wire they want to purchase, they can go to eBay and perform a keyword search for that specific wire. Type in broad terms like "stereo wire," then filter results as desired, or key in more particular search terms to provide more relevant results, such as "10 gauge speaker wire," then filter by wire brand, wire length, price range, or condition. Make sure to purchase the right amount of wire, and any tools or other parts you require to install wire, such as harnesses, connectors, terminals, and other cables. 

Buy Stereo Wire Online with Confidence

Before bidding, carefully read the details in the stereo wire listings, including delivery costs. When buying a more expensive 250 foot roll of Stinger Pro 4 gauge red stereo power wire, for example, make sure the seller insures the product when it ships. And for more information about wire products, ask a seller questions by clicking the Ask a
Question link on the listing page.

Know the eBay Seller

Research the eBay seller to ensure a positive and secure transaction when purchasing stereo wire. Locate the answers to these questions before purchasing.

● Look for the seller's feedback rating from previous buyers, especially in regards to stereo wire

● Find out if the seller offers a money back guarantee for stereo wire

● Ask the seller about the terms and conditions when it comes to purchasing stereo wire


Installing a custom stereo system allows shoppers to get the audio performance that they want. When choosing a parallel vs. series wire, consider specification preferences and overall budget. Correctly wiring an audio system is important, mainly to get the quality of sound desired and to keep the amplifiers used from overheating due to
carrying too big of a load. 

Before buying stereo wire, remember to investigate available options, learn about the different gauges of wire, determine the length needed, and find out how to buy stereo wire safely and securely on eBay.

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