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Connecting Multiple Speakers To An Amplifier

Connecting Multiple Speakers To An Amplifier
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When building a home audio system on a budget, you may need to connect multiple speakers to one amplifier.

However, connecting multiple speakers to an amplifier may prove a bit challenging. You may encounter a few issues, especially if you have no experience in this area.

How Many Speakers Can You Connect To An Amplifier?

Most amps can handle two speakers perfectly well. If you add one or more speakers, you can overload them. However, you should use the number of channels that your amp support as a guide. You should also check the impedance of your amp and speaker to determine the safest way to make the connection.

As a general rule, a parallel connection is ideal if the impedance of your speaker system is 8 ohms or more. If it’s less than that, you should opt for a parallel connection.

Connecting 6 Speakers to a 2-Channel Amplifier

You can connect six speakers to a 2-channel amplifier through parallel or series. Due to impedance issues, a parallel connection is ideal. It’ll put less pressure on the amplifier.

Multiple Speakers On A Single Amplifier

It is important to first realize that by connecting more than one speaker to an amplifier, you are virtually making the amplifier handle more power than using a single unit.

One common configuration is connecting 4 speakers to a 2 channel amp. For example, two similar speakers will double the electric load of your amplifier.

The good news is that most amplifiers can comfortably handle the output of two speakers of similar power requirements.

Multiple Speakers On A Single Amplifier

While most amplifiers can handle the power of two speakers of similar power requirements, they tend to overload if you add more than three speakers.

In fact, some amplifiers will encounter damage if you even connect two powerful speakers. With modern units, there is a limiting circuit that stops the amp from working if that happens. In most cases, the amplifier may blow a fuse or just turn off automatically.

Let’s explain a little further:

Speakers are electrical load devices that use electric current to generate sound. The more powerful the speaker, the greater the electrical current it will normally require.

If a speaker is connected to an amplifier, it will be pulling its power through the amplifier. Of course, the more speakers you connect to the amplifier, the more power the amplifier will need to deliver.

The more power the amplifier needs to deliver, the more electrical current is required. However, every amplifier has a maximum current rating.

If you connect loud, powerful speakers or too many speakers that drive the current through the amplifier to the max, then the amplifier’s fuse will blow, or other components in the device will get damaged, bottom line, the device will simply stop working.

With all that in mind, it’s essential to note that many amplifiers can cope with several speakers connected at a low volume.

At low volumes, the speakers will not be pulling too much power. However, you will start having issues when you run the speakers at high volume.

That said, there are several ways to connect multiple speakers to an amplifier without causing damage. That mainly involves using speaker selector switches.

Amplifier and Speaker Power

It is important to keep in mind the power concerns when it comes to connecting multiple speakers to an amplifier. Your amplifier must be able to provide twice the total power of the speakers. To learn more, check our guide on amplifier and speaker wattage. We answer the question, should your speaker wattage be higher than the amplifier wattage?

Connecting Multiple Speakers To An Amplifier Using Speaker Selector Switches

Speaker selector switches offer the simplest and safest way of connecting multiple speakers to a single amplifier.

Often cost-effective, they are suitable for multi-room installations around your home or while working with a low-power amp (under 100 watts). For example, it’s a great way to connect two 8 ohm speakers to equal 8 ohms

The switch acts like a splitter or a hub, allowing you to power four or even eight speakers with a single amplifier.

To use a selector switch, you simply need to connect its inputs to the right or left channel output of your amplifier.

You can then connect the speakers to the outputs of the switch to start enjoying the sound from multiple speakers. That will protect your amplifier from low impedance issues that may permanently damage the amplifier.

Let’s explain;

Electrical impedance is a measure of the degree to which current is allowed to flow through the speaker.

Connecting Multiple Speakers To An Amplifier Using Speaker Selector Switches

Image Credit: Geoff the Grey Geek

In other words, the lower the impedance, the more current the speaker will allow. To protect the amplifier, speaker selector switches use two main technologies:

1. Series Resistor

Series resistors are common in low-cost selector switches. The resistor (4-6 ohms) protects the amplifier against damage by maintaining the minimum resistance of the amplifier when connected to multiple speakers.

These resistors are very effective in protecting your amplifier, but they tend to get hot in high volume levels. That’s why speaker selectors that use series resistors come with air vents.

speakers and amp series

Given the amount of heat that the resistor emits, it’s obvious that there is a significant loss of energy. For that, speaker selector switches that use a series resistor have an impedance protection switch.

Series Resistor connect multiple speakers

Image Credit: Geoff the Grey Geek

The switch helps you to easily control the series resistor by either including or excluding it in the circuit.

So, how does it work?

To keep the amplifier safe, you should keep the impedance protection activated when using multiple speakers.

You can switch off the series resistors to allow direct connection with zero signal losses when using only one set of speakers or impedance matching volume control

2. Impedance Matching Transformer

This technology is mainly available with cutting-edge speaker selector switches designed to handle a significant amount of power.

Impedance Matching Transformer

The Thevenin equivalent is just a simplified view of the amplifier as a source. It shows its voltage and internal resistance.

The impedance matching switch multiplies the impedance of each connected speaker, keeping the total impedance at the same level as in individual speakers.

That means that they work by maintaining the safe operating load of an amplifier while circulating maximum power in the system.

When buying the connector, you will need to pay attention to the speaker connection compatible with your speakers (types of speaker connectors).

That will ensure that you pick the right speaker selector for your amplifier. Please note that the volume of the amplifier may affect the audio quality of your speakers.

Learn more about impedance matching here.

What If I Have Two Amps With One RCA Jack Each?

If you want to connect multiple speakers and you have two amps with one RCA jack, you can use an RCA splitter, daisy chain the connection, or use a LOC. Learn more about hooking up tow amps with one RCA jack.

How to Use a Speaker Wire Splitter Box

A speaker wire splitter box allows you to play audio from multiple stereo speaker sets.  They also allow you to control your amplifiers and play any combination of your speakers at once.

How to Use a Speaker Wire Splitter Box

As an example, you can use it to control your ceiling speakers, wall speakers, home theater room speakers, and more. In fact, you can use it with speakers of all sizes including 4 6 8 12 inches.

The advantage of these splitter boxes is that each input has an on/off switch. Protection circuitry keeps it running smoothly and prevents speaker burn-out. 

To use a speaker wire splitter box:

  1. For splitter boxes that are passively powered by your stereo, just connect the amplifier to the amplifier ports.
  2. Connect the speakers to the speaker ports (using speaker wires or whatever cable type of speaker connector your splitter uses)

Of course, when using a speaker wire splitter box, you need to check how many 100 watts per channel it can handle and the minimum impedance. You need to also check the gauge of the wire that the speaker box accepts. For example, does it accept 16 gauge or 14 gauge wires

Important Tip:

Make sure that the cables you are using are of the same gauge. If not, the audio signal will be distorted.

Best Multiple Speaker Connector Adaptors

To connect multiple speakers, you’ll need multiple speaker connector adaptors. There are many different types of multiple-speaker connector adaptors on the market, but our top three picks are the best for connecting two or more speakers.

We’ve chosen these three adaptors because they’re quality, affordable, and have a lot of potential applications.

1. Multi-function 3.5mm Stereo Audio Cable

The 3.5mm stereo audio cable is one of the most common multiple-speaker connector adaptor options on the market.

Multi-function 3.5mm Stereo Audio Cable (with 2...
  • ★USE: Angel mall Multi-function audio stereo cable, 3.5mm interface with 2 RCA adapter to achieve more...
  • ★MATERIAL: High-quality oxygen-free copper ensures high fidelity sound quality and provides maximum...
  • ★QUALITY: 5 Feet Black Audio Cable, The quality was far superior to other brand used cables, Gold connectors...

It’s a good choice for connecting two or more speakers because it has three functions: output, input, and microphone. This cable is easy to use and works well with most audio devices. It’s also affordable, making it an excellent option for home theaters.

2. BUDI Cable Multi-Headphone Splitter 3.5mm 5 Jack Multi-Headphone Splitter Adapter

The BUDI Cable Multi-Headline Splitter 3.5mm 5 Jack Multi-Headphone Splitter Adapter is perfect for connecting two or more speakers. It comes with a 5 jack input, ideal for connecting headsets, speakers, and other audio devices.

BUDI Cable Multi-Headphone Splitter 3.5mm 5 Jack...
  • 5 AUX ports for connecting earphones or auxiliary cables, which can easily share sound with up to 5 people
  • A hard-wired auxiliary cable used to connect the device, connect multiple music players at once to mix music
  • Connector type: 3.5mm to 3.5mm

Additionally, the adapter has three different audio outputs so that you can connect them to different speaker sets or amps. The BUDI Cable Multi-Headline Splitter 3.5mm 5 Jack Multi-Headphone Splitter Adapter is an excellent buy at a great price.

3. Gadget-Wagon 3.5 mm Stereo Jack EP Splitter Adapter

The Gadget-Wagon is a 3.5 mm stereo jack adapter that can connect two or more speakers. It’s made from durable plastic and comes with a 3.5 mm stereo jack Adapter. This adapter is perfect for connecting laptops, TVs, and other audio devices to your speaker system.

Gadget-Wagon 3.5 mm Stereo Jack EP Splitter...
  • Use This Cable To Distribute Audio Content In Stereo Format From 1 Source To Many Other Sources
  • Oxygen Free Cables To Ensure 0 Signal Loss And Noise Reduction
  • Fits Snugly And Tightly Into 3.5 Mm Stereo Jacks As Found In Mobiles, Smartphones, Mp3 Players, Led Tv, Set...

It’s easy to use and is excellent for connecting multiple speakers. It’s affordable and has a lot of potential applications. The Gadget-Wagon is easy to use and Connector W3C- compliant, so it’s perfect for connecting your favorite audio devices.

Conclusion

Depending on the amplifier rating and the impedance of your speakers, you should be able to connect a pair of speakers to a single unit easily.

However, it’s wise to use selector switches when connecting more than two speakers in a single unit. That will not only help you to connect the speakers safely, but it will also protect your amplifier from overloading.

Keep in mind that it’s not advisable to run the speakers at high volumes when connected to one amplifier.