We all strive to have a great sound system but may not be able to afford a high-priced stereo system.
Four speakers systematically placed in a room to produce the best sound possible can however produce a listening experience that most single speaker stereo systems can’t compare with.
Connecting multiple speakers to one amplifier can overload and damage your speakers especially if you want to play your audio at loud volumes. If you want more speakers then it is advised to have a 2-channel amplifier with 4 speakers.
You can connect 4 speakers to a 2-channel amplifier in two different ways:
- Connecting the Speakers in-Series.
- Connecting the Speakers in Parallel.
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Determining Impedance Ratings
Deciding on which way to connect your speakers depends on the impedance levels of both your amplifier and speakers. Speakers wired in series raises the impedance delivered to the amplifier, whereas speakers wired in parallel lowers the impedance to the amplifier.
It is important to stay within the minimum and maximum impedance levels specified for both amplifiers and speakers. For amplifiers, these limits can be found by referring to the owner’s manual or an online specs table. Impedance levels are measured as Ω (ohms)
Most speakers have labels on them indicating the minimum and maximum impedance ratings but if not displayed, refer to your manual.
Calculating in-Series Impedance Rating
To determine which way to connect the speakers: add the impedance of the two speakers you will connect with one channel together. If the sum of impedance of both speakers lies within the impedance limits of the amplifier, then connect the speakers in series.
For example, if you have two speakers each rated at 4-ohm the sum of impedance of both speakers will be 8-ohm. If your amplifier is rated as handling 8-ohm per channel, then you can safely connect the speakers in series.
Calculating in-Parallel Impedance Rating
If the impedance levels add up to a rating that is higher than what your amplifier can support, then you must determine if it is possible to connect the two speakers in parallel.
Multiply the ratings of the two speakers and divide that number by the figure you got by adding them together. For example, if you have two speakers rated at 4-ohm then 4×4 = 16, divide that by 4+4 =8 which gives you 2 ohm when connected in-Parallel.
If 2 ohm falls within the minimum impedance guideline for your amplifier. then you can wire your speakers in parallel. If this is lower than the recommended guideline then wiring the speakers in parallel is not recommended.
An impedance that is lower than the recommended level will draw more power than your amplifier will be able to provide and could cause overheating and possible cutouts.
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Connecting the Speakers in-Series
The following steps will help you wire four speakers to a two-channel amplifier in series:
- Connect a wire from the amplifier’s left-side positive terminal to the positive terminal of your first left-side speaker.
- Connect a wire from the negative terminal of your first left speaker to the positive terminal of the second left speaker.
- Route the third wire from the left-side negative terminal on your amplifier to the second left speaker’s negative terminal.
- Repeat steps 1-3 to add the right-side speakers to your setup.
Pros and Cons of Connecting Speakers in-Series
Pros:
- Due to it increasing the equipment’s overall resistance, in-series connections allow the amplifier to run more efficiently and cooler.
- A constant specific amount of amplified output is received by each speaker.
Cons:
- If one connection fails it can cause all the speakers to stop working.
- Sounds tend to be not as crisp and vibrant as with an in-parallel connection.
● Higher frequencies are not as clear. They tend to get lost.
Connecting the Speakers in-Parallel
Use the following steps to connect four speakers to a two-channel amplifier in parallel:
- Connect the left-side positive and negative amplifier terminals to the positive and negative terminals on the first left speaker.
- Connect two more wires from the same left-side positive and negative terminals of the left-side amplifier to the positive and negative terminals of the second left speaker.
- Repeat steps 1-2 for the right-side speakers.
It is critical to ensure that wires do not cross within the terminals as this could cause you to not receive the quality of sound you are looking for.
Pros and Cons of Connecting Speakers in-Parallel
Pros:
- When one speaker fails, the other speakers can continue to function.
- Due to a lower impedance rating the sound produced is of a higher and crisper quality.
- The speaker volume or output can be increased in conjunction to the amplifier doing the same.
Cons:
- Overheating can occur if there is a short circuit within the setup.
- To produce the best audio quality, you must get the load impedance to the lowest setting your amplifier will support.
Types of Amps
There are two main types of amps in use:
- Solid-State Amplifier
With this amplifier, the power rating is difficult to control with a multi-speaker in-parallel wiring installation. The power rating adjusts as the impedance changes meaning you could get more power with lower impedance and the amplifier could overheat.
- Tube Amplifier
In the case of a tube amp, the power rating will not change when the impedance is adjusted. It is therefore a more versatile amplifier to use as it can be used for in-series or in-parallel connections without worrying about power changes.
If you want to connect four speakers to a two-channel amplifier you will need a minimum of an 8-ohm rating if you want to connect four 4-ohm speakers.
Conclusion
Whether you decide to connect your four speakers to a two-channel amplifier in-series or in-parallel is dependent on the quality and most importantly the impedance rating of both the amplifier and the speakers.
Never overload the amplifier or it will be damaged. Always try to keep the load of the amplifier within the specified impedance levels to get a clear sound. Overloading can lead to damage to the amplifier or distorted sound.
The sound of your system cannot be increased solely by increasing the number of speakers. It is dependent on the power of your amplifier. If you want an improved audio system you need to upgrade your amplifier and speakers.