Speakers in Parallel Calculator

Simple 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).

\large{R_{Total}}=\frac{1}{\frac{1}{R_1}+\frac{1}{R_2}+...}

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 calculators below.

Simple Calculator for Speakers in Parallel

Below is a separate calculator for 2, 3 and 4 speakers wired in parallel. Following these simple calculators is another calculator which can be used for more complex series/parallel configurations.

Simply type the impedance of each speaker into the white boxes of the appropriate calculator. The total impedance for those speakers connected in parallel will be calculated.

Also for each speaker is a calculated percentage. The shows how the power output of the amplifier is shared between the speakers. Power sharing is a consideration when using speakers with different impedance. See How Multiple Speakers Share Power for further details.

 

These calculators 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.

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.

Calculator for Series/Parallel Speakers

This calculator can be used for a series/parallel configuration or for two speakers in parallel. It goes a step further than the calculators above and allows you to enter the maximum power output of your amplifier for the calculated total load impedance. The maximum power through each speaker is then calculated. Also the difference in power between the highest power and the lowest power in the speakers is given as a ratio and in decibels.

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

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154 COMMENTS

  1. I have a 6 speaker kit “3 in each tower” the kit says the impedence once assembled is 4 ohm. The tweeter is 8ohm, the mid 4ohm, and the sub 4 ohm. So if I wire the mid and the sub in series that would be 8 ohms, and then the tweeter in parallel that would bring me to 4 ohms. Is this correct. I used the calculator above for series/parallel and I place the mid ohm value “4 ohm” in speaker box one, the sub ohm value “4ohm” in speaker box 3, and the tweeter value “8ohm” in box 6. Is that correct, meaning I have calculated my sub and mid in series, and then the tweeter in parallel? Thanks so much in advance.

    • Hi Kyle,

      You have used the calculator correctly.

      However I assume the “kit” also involves a crossover of some type. The crossover allows the speakers to be wired in parallel, but not every speaker gets to see every frequency – only the frequencies they are optimized for. As impedance is frequency dependent, any one frequency will mostly see only one speaker. But this all gets complicated, and it is not as easy as a simple calculation of speakers in parallel – that is why speaker designers get the big bucks, and as installers we trust them.

      Geoff

  2. Hi Geoff, I am trying to tackle an “out of the box” setup…I am wanting to use a car cd/dvd player with speakers that would connect to my television in my bathroom for when taking a long soaking bath. I already know and have purchased a converter for allowing me to power the cd/dvd player, my question is first can I use a waterproof “indoor” speakers or do I need to stay with car speakers or more likely marine style speakers. Also in dealing with ohms, if the cd/dvd player is rated for 4ohm speakers, can I still use 8ohm speakers in parallel to equate to 4ohm. Also assuming that I stay within the given watt ranges for both the speakers and the cd/dvd unit.

    • Hi Tim,

      You seem to have the basics sorted.

      As you say, you can technically run any speaker with any amp, as long as the impedance and the power are thought about.

      You can run two 8 ohm speakers in parallel to make 4 ohms, or the amp will also work fine with only an 8 ohm speaker – it just wont have as much maximum power – but that shouldn’t be a problem for you.

      Enjoy your bath!

      Geoff

  3. hello,
    I have 4 speakers by 4 ohm and one subwoofer by 8ohm. My amp range is from 8 to 16
    can i fix this ?

    • Hi Darius,

      I assume the amp is stereo, so you only need 2 speakers on channel (left and right). Therefore you could connect two speakers in series, this will give you 8 ohms for each channel.

      If the sub has speaker in and out connections. Then you could connect both channels to the sub, then from the amp to each set of series connected speakers.

      hope this helps

      Geoff

  4. Hi Geoff,

    I have an old set of LG speakers HX995TGW. The main unit is broken and i was wondering if i could reuse them and pair them with my Denon AVR 1800 receiver. Below is all i could get from their manuals.

    Satellite & center speaker specs:
    Type: 2 way 3 speaker
    Impedence: 4ohms
    Input power: 180W
    Max. Input power: 360W

    Receiver specs—
    Rated output: stereo (2ch driven)
    75W + 75W (8ohms w/ 0.05 T.H.D)
    110W + 110W (6ohms w/ 0.7 T.H.D)
    Dynamic power:
    100W x 2ch (8ohms)
    145W x 2ch (4ohms)
    170W x 2ch (2ohms)
    Output Terminals: 6-16ohms

    • Hi Bernardo,

      According the the specs you supplied, the speakers should be fine.
      It is highly probable that the old amp system was not as powerful as the Denon, so don’t run the Denon at full power or you will over power the speakers.
      As I often say, always listen for distortion. Distortion is the early warning sign that something is about to break, so turn it down.

      hope this helps

      Geoff

  5. Hello Geoff… In my church I have an Power AMP – StudioMaster DJA 800 which has 2 channels and it give out @ 8ohms. I can connect 2 x 8 Ohms Speakers @165W RMS and @4ohms I can connect 2 Speakers @250W RMS. I mean connect 1 speaker on channel 1 and the other on 2

    The problem is the folks have given me 12 speakers of Quest MS801W whose power handling is between 120 to 240W @8Ohms…so I have to connect 6 speakers to one channel and then other 6 to the other channel….
    So if I do a series/parallel connection on both side I will get 5.33ohms in total on each side which is between 4-8 ohms

    Is is a good connection and also how much power will each speaker drive, I assume the power for each speaker will be somewhere between 30-40w, but isn’t this less that the min requirement of each speaker as per the specs……or will it just work fine.

    • Hi Darren,

      You seems to have it all worked worked out.

      Connecting them ins series parallel will work. Although as you know it will reduce the power going to any one speaker.

      A speaker will work fine with less power than the recommended. The recommended power is for best performance, but they will still work.

      My question is why? Adding more speakers can mess the sound if you can hear more then one speaker at any one time. The only reasons to have more speakers is to spread the sound – it will not make the sound louder overall.

      Geoff

  6. If I have 2 200watt 8 ohm speakers and an amp that will provide 400 watts rms @ 4 ohms x 1 then am I all good to wire in parallel?

    • Hi Jordan,

      Yes you are correct, everything adds up.

      Just be aware that even when all the figures adds up, if you try hard enough you can still blow either the speakers or the amp. Always listen for distortion. Distortion is the early warning sign that something is about to break, so turn it down.

      Geoff

  7. I have a speaker. On which neither the Ohm nor the watt have been written. So how do I know ohm and watt?

    • Hi Sandeep,

      Without any marking or information it is very difficult to know.

      All you can do is assume the impedance is at least 4 ohms.

      Sorry I can’t help any more

      Geoff

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