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. 

Randy (Florissant, Co)

Hello, I recently purchased cheap, a Yamaha Rx-V1, Yamaha Ax-596 and some difinitive BP2002 speakers with a video projector. I started hooking up everything and found out one of the Dedicated Amps supporting the sub in one of my towers is blown. I tried finding a replacement and definitive support doesnt support these anymore. Is there an after market type amp i could potentially use. If not, what are your thoughts on running the mid and high speakers from the Rx-V1 and pulling the amps from each speaker and using the AX-596 specific for the subs? I tried this on… Read more »

Jacob (Kansas City)

What would you recommend for line arrays with multiple small speakers? Any more than a maximum of three speakers at four ohms each causes a problem either in series or parallel, the former lowering amplifier output too much and the latter overloading the amp. Is the main solution to simply use a bunch of smaller amps? Or by increasing ohms via speakers in series can you use higher wattage than the speakers are rated for?

Clif R. (Rock Hill, SC)

Quick question and I may be over analyzing. I have a Yamaha receiver RX V377 and want to add just one speaker to one of my rear channels. My speakers say they are 4-8 ohms. From what I have read should I wire this in series? I do not want to overload my receiver and I believe there is a way to set the impedance lower. I assume the default is 8 min and I know I can change it to 6 min. I do not want this one extra speaker to cause my overall sound of my system to… Read more »

Darroll (Perkins, OK, US)

Geoff, I have a Sony BDV-E2100 Blu-ray Disc Theater System w/ Wi-Fi. Due to the layout of my awkward room size I have two couches backed into each other in a corner. They are both against the walls with an end table in the corner. The TV is in the opposite corner of the room. My concern is the rear surround speakers. I have one directly above the far end of each couch mounted at the ceiling angled down toward the center seat of each couch. The problem is that unless you are sitting on the end table in the… Read more »

Ignacio (Denmark)

Hello Geoff, many greetings from Denmark. I would like to ask for your help on this matter of me needing to add just a couple of extra to add high-range sound to my existing combo. I am atracted to the possibility of buying a speaker selector with protection and separate volume control, but I am not good at understanting all the equations on your articles. Therefore I need a down to ‘idiot’ solution ,-) I got a DENON NETWORK CD RECEIVER RCD-N9, which is said to deliver 2x65watt at 4ohms. This fine product is accompained by two state of the… Read more »

Steven Scott (Lebanon, OR, USA)

Hi Geoff, Very nicely written article. I just wanted to make sure I understand everything correctly, so I don’t overload the receiver/amps. I have an Onkyo TX-NR737 7.2 channel receiver (with the Firmware Upgrade allowing for Dolby Atmos). I have a set of Onkyo HTP-590 7.1 channel 6 ohm speakers and using 5 of the 8 of them (Center, Surround R&L and Rear/Height R&L. I also have an Onkyo SKW-580 powered SUB and a 100 amp 2 channel plate amp- that drive 2 AURA AST-2B-04 transducers (in series) connected to the SUB OUT of the receiver via an RCA Splitter.… Read more »

Roger (France)

Hi have been looking at your excellent website but need clarification on one point. I have an amp rated 20w + 20w 6 ohms. There are 2 existing speakers of 6 ohms each and I want to add 2 more of 8 ohms each (85w each). So 4 speakers in total, each side having 1 x 8 ohms and 1 x 6 ohms. From your speaker calculator I get a figure of 1.71 ohms for all these speakers together, in parallel, but I don’t know how this relates to the amp. Would these work best wired in parallel or series?… Read more »

Trung (Columbus)

hi Geoff, Thank you for the article. I have a question. I have 1 channel amp rated 1.5 – 4 ohm. I have 4 speakers they are 2 ohm each. I wired them in parallel, 2’s on the left side and 2’s on the right. Based on your article, seemed that I overloaded the amp by 0.5 ohm? I do not play it loud, at most 1/2 of the volume. Am I ok with this configuration? I tried to wire the speakers in series, but the sound came out less powerful in bass and mid. Thank you in advance for… Read more »

Ben (Edinburgh)

Hi Geoff, I have been trying to get my head round your calculations, but alas mathematics was never my strong point. I have a Cambridge audio SR10 V2 amplifier rated 85 watts into 8 ohms. The amp has two pairs of speaker outputs, and until now I have been running a pair of Monitor Audio Bronze BR2s (6 ohms) from output 1 and a pair of old Kenwood ES (8 ohms) from output 2. All happy. However, I’ve now found a pair of old Hitachi HS-J2 (4 ohms). Ignoring any or all aspects of “why would you want to run… Read more »

Jishnu Anilkumar (Trivandrum, India)

Hi Geoff, we are about to do a small haunted house kinda thing. We have two home theater systems and two stereo amps. We need to provide same inpuuts to all four devices. We will give input from my laptop. We are thinking of using a cheapp headphone splitter to split input from pc to the amps and home theaters. Is that a bad idea? Can anything go wrong like blowing my pc sound card?