The calculator below is useful in determining the total impedance of speakers in parallel. It also calculates how the power is shared between the speakers. If all the speakers have the same impedance, the calculation is relatively simple.

### Simple Impedance Calculation for Speakers in Parallel

If all the speakers in parallel have the same impedance, then the calculation is easy. Simply divide the impedance by the number of speakers in parallel.

Example 1: Four 8 ohm speakers in parallel: 8 divided by 4 = 2 ohms.

Example 2: Two 4 ohms speakers in parallel: 4 divided by 2 = 2 ohms.

### Not so Simple Calculations for Speakers in Parallel

For calculations involving speakers in parallel with different impedance, the following formula is required (it can be used with speakers of similar impedances too).

If you have a calculator with *1/x* button then this calculation is not too difficult. If you don’t have that function on your calculator, or if you don’t like formulas, check out the calculator below.

### Using the Calculator

The calculator can be used for 2, 3 or 4 speakers wired in parallel.

Simply type the impedance of each speaker into the white boxes (or use the drop-down values). Use N/A for unused speakers in this calculator. The total impedance will be calculated for the entered speakers.

Also calculated for each speaker is its percentage share of the amplifier’s output power. This is useful as power sharing is a consideration when using speakers with different impedance.

“Power Differential” is the final calculation. This calculates in dB (decibels) the power level difference between the highest and lowest power as it is shared across the speakers. This shows the power level difference when using speakers with different impedance.

###### Amplifier Power Calculator

The bottom section of the calculator helps in matching the speaker combination with your amplifier. This is not necessary if you only want to know the total impedance and/or the power ratios.

However if you are connecting these speakers to your amplifier, it may be helpful to input the amplifier power and the associated speaker impedance. In the specifications for your amplifier, it should say something like:

Amplifier power: 80 watts continuous average power @ 4 ohms (2 channels driven, THD 0.08%, 20Hz-20kHz)

This tells you the maximum continuous power the amplifier will deliver into a 6 ohm load is 80 watts. In the calculator below, for this example, you type in 80 for the power and 6 for the impedance. Be aware, some specifications state RMS power rather than continuous power. These are effectively the same.

The calculator will display the effective power of the amplifier for the calculated total impedance of the series speakers. Also displayed (under each speaker’s power %) is the actual maximum power the amplifier will supply each connected speaker. A comment on the suitability of the calculated total impedance for your amplifier is also provided.

Download Calculatoras Excel File |

`Prices in US$` |

Note: the calculated output power for the amplifier is based on a theoretical “ideal” amplifier. In practise, your amplifier may produce slightly more power.

###### Further Reading

This calculator will help you understand the total speaker load on your HiFi amplifier. For a better understanding of this and what to do about it, read the articles How do I Connect Multiple Speakers to my HiFi Amplifier and How to wire four HiFi speakers or How to connect 2 speakers to one amplifier or watch the video in the article Understanding Speaker Impedance.Also see How Multiple Speakers Share Power for further details about the percentage power calculations. For more details about the effective amplifier power at higher impedance loads, see How Impedance Changes Amplifier Power.

Please Note: all these calculations are for connecting manufactured speakers (boxes). They are not used when building your own speaker boxes and connecting multiple speakers in a cabinet using a crossover circuit. A crossover splits the signal into different frequencies for each of the speakers and makes the total impedance calculation complex (as impedance is frequency dependent). That is why speaker designers get the big money, and as installers we benefit from their expertise.

If you need further advice on connecting speakers (boxes) in parallel, please read the FAQs before submitting your question. You may also find an answer in the comments below.

*Disclosure: If you buy through this Amazon USA link Geoff receives a small commission from each sale.*

European and Australian readers can use the links on the side panel - Thanks for the support

Hi,

We are building 2 boxes with 8 4″ full range speakers and 2 12″ woofers in each. The 4″ speakers are 8ohms. Here’s our dilemma… How can we wire the 8 4″ 8ohm speakers and end up with an overall impedance of 8ohms(not counting the 12″s. Those are fine.)? We need to get as close to 8ohms as possible. Thanks in advance.

Hi Erik,

As you have found out, it is not possible to arrange 8 x 8 ohm speakers and get 8 ohms as a total impedance. The only real alternatives are 16 ohms or 4 ohms.

An option would be to use only 4 x 8 ohm speakers.

Sorry, that is the way it is.

Geoff

hello sir

i got 8 speakers i wanted to connect them to my amp (4 to 8 ohms and 360 watts) i was gonna connect them to 1 channel since the 2nd channel is broken every channel got left and right (devided the speakers to each side )

the speakers : 2x(6ohms-45watts) 2x(4ohms-80watts) 2x(4ohms-60watts) 2x(4ohms-30watts)

the amp : onkyo(model:A-08) 4 and up to 8 ohms per channel-360 watts

can you tell me if its ok to connect them to the amp and if it is how should i do it Series or Parallel

thanks for helping in advance 😀

best wishs john

Hi John,

Connecting 8 speakers in one room is not a normal thing to do, and will not make it sound any louder, as the power is shared by all the speakers. However if you want to do this, there are several ways you could connect the speakers.

One way would be like this:

This would give an overall load impedance of 6.2 ohms, which the amp will cope with nicely.

Hope this helps

Geoff

hello geoff

thanks for your help but the amp is a sterio amp (left and right )

there is 2 channels A and B

i wanted to connect them to A channel only with left and right (4 at the left side and 4 at the right side )

Sorry John, I thought one side was faulty.

To connect four speakers to one channel, there are a few series/parallel combinations you could use. This one gives a total impedance of 4.4 ohms.

Does this help?

Geoff

yes perfect it sound great

thank you alot for your help i wouldn’t have done it without you my kind friend

best wishs to you in your work

john gazoulie

Hello Geoff,

Is it possible to take 8 8ohm speakers and turn them into a 2ohm load, my amp is a 1ch 2ohm stable amp so I need one single wire at the end, I tried to do some calculations and I couldn’t figure out a way to get it below 4ohms, if you could help that would be great, Thanks

Hi Jonathon,

You are right, there is no easy way of connecting them to make an equivalent 2 ohm load. Of course the amp will still work well with a 4 ohm load, it just wont be at its possible maximum power, but it will still work fine. If you want maximum power, can you use just 4 speakers, as this way all 4 will have more power than using 8 speakers.

Geoff

Hi Geoff,

I’m not an expert and I must realize a musical background in a shop.

I plan to buy a Marantz M-CR611 that writes in the back from 4 ohm to 16 ohm

In the specification sheet is written 60W 6 Ohm (2 channels) that means probably 30W 6 Ohm on 4 channels.

I plan to buy also 4 pair of speakers Yamaha NS-IC600 8 Ohm

I think is better to connect the 2 speakers in parallel for each channel, what do you think?

Thank you.

Vittorio

Hi Vittorio,

From my understanding what you say is correct. Wiring the speakers in parallel will give you the most power in all the speakers, yet it does not compromise the amp as it is within its parameters for total load impedance.

Geoff

Hi Geoff……. I have two sets of 15 inch subs one set is dual voice coil 2 ohm, the other set is dual voice coil 4 ohm, how can I wire them all together 2 ohm if possible……..

Hi Rahshan,

Can you wire the 2 ohms voice coils in series, that will make that sub 4 ohms, then that one in parallel with the other 4 ohm one will give you the 2 ohms total you are after.

Geoff

Hi Geoff: I am using an Onkyo TX-RZ800 (135 watts per channel x 2 into 8 ohms) to power a 2 channel speaker setup. I will have 4 Polk Audio rc80i (8 ohm) speakers in-ceiling. How can I maximize power output to the speakers? My thoughts are to run these speakers in parallel which should decrease resistance to 4 ohms (which the amplifier can handle) and which should bring current to approx. 225 watts or so. My other option is to hook one pair up to the front speaker outputs and hook the second pair up to an assignable output… Read more »

Hi John,

Your thought of wiring them in parallel is the normal way of doing this. Given that the Polk Audio brochure states your speaker’s recommended amplifier is between 20-100 watts, it seems to be a perfect match without trying to put more power into them than they can handle.

60 watts into these speakers will produce 106dB of sound when standing underneath them. That is pretty loud for a domestic install.

hope this helps

Geoff

Hi Geoff,

Like all your other requests I’m in need of help as maths or physics were not my strongest subjects. I have a Yamaha A3050 av Reciever and am running a centre, two front and 4 ceiling speakers. The two front speakers are KEF Q900 towers, the 4 ceiling speakers are Jenson ceiling speakers 6 ohms each. The centre speaker is an old 8ohm Onkyo model. I am also using the Reciever to run a separate zone out doors which will only be running 2 Jenson ceiling speakers. What’s your recommendation on wiring this set up?

Hi Angelina, From my understanding of your setup, there is no maths or physics required as each speaker will have its own amp (there are nine individual amps in the A3050). The surround sound room will be wired as a 7.1 system, as shown on page 22 of the manual (of the amp’s manual). The two outdoor ceiling speakers will be run from the zone two amp. The front and centre speakers will connect to the front and centre amp. The ceiling speakers will be connected to the surround and surround back amps. The outside speakers will be connected to… Read more »

Mr.Geoff

We have 12 Bose 251 speakers of 8 ohms each, 6 speakers for channel 1 left and 6 speakers channel 2 right in ceiling but I’m not sure regarding for wiring if its series or parallel they make with the contractor. But they use home theater receiver amplifier and is not working properly. So my question is what kind of amplifier is required?

Thanks,

john

Hi John, The main problem is the total impedance for each channel. You say the Bose 251 are 8 ohms each, however the manual says they are 6 ohms each. Either way, having 6 of them wired in parallel gives a total load impedance of around 1 ohm. This is four times what most amps can work with. This can be overcome by wiring the speakers in a series/parallel combination. For each channel, you need 3 lots of 2 speakers in series. That is, 3 pair of two speakers in series should be wired in parallel. This sounds complicated, but… Read more »

What is the best way to wire my four Control 65 P/T speakers to my JBL 2120 Amp/Mixer?

The speakers are 8 ohms each. From what I have learned from your articles, I plan to wire them in parallel.

Thanks,

Rob

Hi Rob,

I assume you don’t have the optional transformer box to make the output into a 70 volt system, so you will need to make sure the selector switch on the top of the speakers is switched to 8 ohms and not one of the 70 volt settings.

Each amp (left and right) will work fine into a total load impedance of 4 ohms. Therefore you can connect 2 speakers in parallel to each amp as you say, as two 8 ohm speakers in parallel gives a total load impedance of 4 ohms.

All good,

Geoff

Excellent. Thanks for your advice.

hello

I have a 6/8 ohms amplifier YAMAHA RX 479 – 80/115 watts.

I want to connect the surround channels with serial speakers. 1 speaker 60 watts 3 ohms + 1 speaker 15 watts 8 ohm.

Is that a good choice. I know the 15 watts speaker will go louder than the 60 watts one but it’s just for surround, I listen to decent volume in surround. My question is: is the receiver protected this way from damage?

Thanks

Hi,

The amplifier will have no problems if you want to connect both speakers in series to the surround sound output.

However I wonder why you want to. The 60 watt speaker on their own will be better than being in series with the 15 watt speakers.

Geoff