How to Connect 2 Speakers to 1 Amplifier

In this article we look at how and when to connect 2 speakers in parallel or series. Both the theory and practical points on how to connect 2 speakers are discussed. Connecting 2 speakers in parallel or series to your amplifier is useful when:

  • you don’t need to turn each speaker on or off individually, or
  • you don’t need to have separate volume controls for each speaker.

If you need to turn each speaker on or off individually or have separate volume controls, you may need a speaker selector switch. In this case you should read the articles on connecting multiple speakers, wiring 4 speakers, and/or my summary of speaker selector switches.

Many people get confused when we talk about a stereo amplifier. A stereo amp simply has two amplifiers built into the one box. We are not talking about connecting two speakers to a stereo amp, as that simply involves connecting one speconenct 2 speakers to stereoaker to each amplifier (left and right). There are many cases when you want to connect four speakers to a stereo amp, that is, to connect 2 speakers to each amplifier – or four speakers in total. For the rest of this article, when we talk about an amplifier, we are talking about either the left or right amplifier only.

You may want to connect 2 speakers to one amplifier without individual switching or volume controls if you:

  • have a large living area with four ceiling speakers, or
  • want to cover a large backyard with four speakers, or
  • have any situation where two speakers are not enough.

The are two basic ways of connecting two speakers together – either in series or parallel.

Should 2 speakers be connected in Series or Parallel?

Whether 2 speakers connected to one amplifier should be in series or parallel mostly depends on the impedance of the speakers.

The impedance of the speakers should be written on the back of the speaker Connect 2 speakers 8 ohmsor speaker box. The impedance of a speaker is normally 4 ohms, 6 ohms or 8 ohms. If it isn’t written on the back of the speaker, check any paper work that might have come with the speaker, or look up the specifications on the web. The Ω symbol is often used instead of writing “ohms”.

If both speakers are 8 ohms or more, then the speakers can normally be wired in parallel.

If the speakers are less than 8 ohms, then to be safe, you should wire them in series.

Connect 2 Speakers in Parallel

To calculate the total load impedance of speakers in parallel, see my Speakers in Parallel Calculator.

If both speakers are 8 ohms or more, then it is normally safe to connect them in parallel. This is because two 8 ohm speakers in parallel makes the total load impedance 4 ohms. Most HiFi amps are designed to have a total load impedance of 4 ohms or higher, but not lower than 4 ohms. If your amp is not specified for 4 ohms (some are 6 ohms or 8 ohms minimum), then you should consider wiring your two speakers in series.

This diagram helps show why speakers connected this way are called “in parallel”

Connect 2 speakers in parallel

They are known as being in parallel because, well, they are wired in parallel. Admittedly, I’ve drawn them so they look like being in parallel. However, in practice, we wouldn’t use so many cables and connections. For practical ways of connecting 2 speakers in parallel, see the table below.

If your amplifier has an A and B speaker selector, you can use this for a simple way of connecting two sets of speakers in parallel.

Connect 2 Speakers in Series

To calculate the total load impedance of speakers in series, simply add the impedances together

If both speakers are less than 8 ohms, or the amplifier requires a total load impedance greater than 4 ohms, then it is best to connect the speakers in series. This is because two 4 ohm speakers in series makes the total load impedance 8 ohms. Two 6 ohm speakers in series makes the total load impedance 12 ohms. Most amps work fine with a load impedance of 6-16 ohms.

This diagram helps show why speakers connected this way are call “in series”

Connect 2 speakers in series

As you can see, the two speakers are in “series” with the each other.

How to Connect 2 speakers in Parallel and Series

Below is a table showing how to wire up two speakers in parallel and series for common scenarios. Keep in mind these diagrams are for one amp only (let’s say the left amp), you will need to duplicate this for the right amp also.

If you double click on a diagram you should see a slightly larger version for easier viewing.

Practical Ways to Connect 2 Speakers in Parallel and Series
When all cables are run back to the amplifier location
Connect 2 speakers in parallel
Parallel: Both speaker cables are connected directly to the amplifier
Connect 2 speakers in series
Series:Join two of the wires as shown separate to the connections on the amp.
When the second speaker needs to be connected off the first speaker
Connect 2 speakers in parallel
Parallel: Join the cables of the second speaker to the cables on the first speaker
Connect 2 speakers in series
Series: Cut one wire near the 2nd speaker, and connect the 2nd speaker "in series" with the cut wire.
When there is a (long) cable run to be split to go to both speakers
Connect 2 speakers in parallel
Parallel: Join the cables from both speakers to the cable from the amplifier
Connect 2 speakers in series
Series: Join the two speakers in series, then join this to the feed cable
When the cables from each speaker come back to a wall plate
Parallel: Simply join the terminal as shown
Parallel: Simply join the terminal as shown
Connect 2 speakers in series
Series: The series connection is made with one join

You may have noticed that no matter which scenario is used, all the parallel diagrams are technically wired the same as each other – if you doubt me, trace the connections with your fingers on any two of the parallel connection methods. You can do the same for the series connections below as they are also the same as each other.

Keep in mind that changing the total load impedance of an amplifier will increase or decrease the power output of the amplifier. Connecting in parallel normally increases the output power, while a series connection normally decreases the power output of an amplifier. See Multiple Speakers Change Amplifier Power for more details.

Each speaker may have a different sensitivity which may mean there will be a level difference between them. For more on this see Understanding Speaker Sensitivity.

Also if the speakers each have a different impedance, then there will be different power levels available to each speaker. For more detail see How Multiple Speakers Share Power. 

Summary of Connecting 2 speakers

There are only really two ways to connect 2 speakers to one amplifier – either in parallel or series.

If each speaker has an impedance of 8 ohms or more, then you can generally connect them in parallel.download article

If each speaker has an impedance below 8 ohms, you should wire them in series.

If you need to switch each set of speakers on or off, or you want separate volume controls, see my articles on connecting multiple speakers, wiring 4 speakers and/or my speaker selector switch summary

If you still have a question on how to wire two speakers, please read the FAQs before submitting your question. You may also find an answer in the questions and answers below. 

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Kyle G (Bakersfield)

I have a Yamaha PA system Stagepas 300. The 2 speakers I have now are not cutting it for our oudoor conferences. Do i need a whole other amp so i can run 2 more speakers? or is there some kind of adapter I can get that will allow me to add additional speakers. Not sure what adapter/hookup I would need. Thanks for any input

Tom

Hi Geoff, I’m completely new to this sort of thing so this is probably a very simple question.

I have a two pairs of speakers that I need to wire into one amp.

I have:
NAD 7125 Stereo Receiver
Wharfedale XP2 (6 ohm)
Wharfedale Modus Cube (6 ohm)

My XP2’s are currently direct into the amp but I’m unsure on how best to wire up the Cubes.

From reading this article, I think I’ll be ok wiring these up in Series – can you confirm this?

Cheers, and great blog – it’s been very useful.
Tom.

Holly (Grand Isle)

Hi Geoff, I just got an audio technica lp60 turntable, and after many hours of comparing and contrasting speakers, I decided to go for a pair of Pioneer SP-BS22-LR Bookshelf Speakers. I’m extremely new to this whole thing, so I’m trying to figure out how or if I can pair these two together. I was wondering if you could fill me in on the other accessories I would need to connect these two things, and maybe even some visual aids to help me connect them? Based on my research, I believe I need to also purchase an amp, but I’m… Read more »

Justin Stuhlsatz

First off, wow, the amount of simple, easy to understand information here is amazing. Thank you for all of this! I think you’ve answered my questions, but I just want to make sure I’m on the right track. I’m using the OnQ LryiQ audio system at my house… it will by no means ‘rock the house’ but its good enough for background music and to make some noise while you’re cleaning the house. I’m ready to add a zone to my living room/ kitchen. It’s a u-shape around a staircase, so I want to use 1 keypad (the amps are… Read more »

Damien (Dublin, Ireland)

Hi Geoff.
I have recently bought 4 ceiling speakers and a power amp desperately of the Internet. The amp is a SPL 400 it has 2 channels boosting 200 watts each, these are the specifications of the amp: Output power:8 Ohms: 2x 150W, 4 Ohms: 2x 200W, Impedance: >4 Ohm.
The 4 speakers I have are 100v line speakers and are rated at 50 watt each and are each set at 8 ohms on the speaker, do you think this will work Geoff ?
Many thanks
Damien

Jishnu Anilkumar (Trivandrum, India)

Hi Geoff,
I have a 2 channel car music system in my car with 50 watt for each channel. I already have a pair of 300 watt peak power front speakers with 4 ohm impedance. I want to connect two more speakers (jbl cx s679, 4 ohm impedance, 400 watt peak power). So I am thinking of connecting it in series. But my question is this, whether the sound gets bad because of the lack of amplifier power? Buying an external amp is not going to fit my budget.

Nick

Hello Geoff, Great site very informative, My question is: I have a Samsung 2.1 120watt soundbar model hw-j355 techspecs are: Main unit: 30watt/channel, 8ohm, thd=10%, 1khz subwoofer 60watt, 3 ohm What. I would like to do is connect one extra speaker to each channel. The speakers i have are rated 4ohm 6watt. From what I have understood is that I should connect them in series ,with total impedance on each channel at 12 ohms. I would like to know how will this affect the loudness of the system. For example as it is now I have the volume at 40%… Read more »

Patrick Campbell (Robinson, USA)

Geoff, I am new to stereo audio componentry and had a friend install an amplifier and two speakers for me. I have used simple systems in the past for computers and bose consumer grade stuff, so I’m not sophisticated. The audio engineer installed the following: Amplifier, Technical Pro, AX1200, 1200 watt 2 channel Speakers, 2, Rockville, RSG-10, 8 ohms I’ve always seen speakers hooked up with each channel going to each speaker, so each speaker is stereo. My friend installed one wire to each speaker however, left channel on left speaker and one to right speaker. I’ve never seen this… Read more »

Dan

Hi Geoff,

I have read through this and would like to ask some questions I have a denon PMA-250III it’s has 25 watts per channel at 8ohms and a speaker load of 4-16 ohms am I right in saying I can put 4 of my pioneer speakers that are 40 watts and 8ohms into my amp (2 in parallel in each channel)?

Kind regards

Dan

Sujith V (India)

Hi Geoff. This is sujith from India. I am having an Old DENON DHT-390 , 5.1 AMP and speaker system. I recently got 2 Yamaha NS-8390 speakers, which was lying unused at my bro’s place. Now I wish to connect these to the AVR, and also keep my existing speakers. I am planning to do the following. connect the Yamaha speakers in the front channel (speaker is 8 Ohms) whereas my Denon Speakers are 6 Ohms a piece. so I think replacing 6 ohm speakers with 8 Ohms will be ok. Center and SW stays where they are. now the… Read more »