Series Or Parallel Speakers – Which is Better + Pros And Cons

Ever wondered why there’s a difference between series vs parallel speaker wiring? How about how it affects power, sound, and the speaker (Ohms) load your radio or amp sees?

There’s a lot more to series vs parallel speaker wiring than you may realize. I’ll explain it all here in a way anyone can understand.

Read on to find out what you need to know.

Which is better series or parallel speaker wiring?

series vs parallel speakers which is better man thinking image

Here are the main points you need to know for series vs parallel speaker wiring:

  • In nearly all cases speakers should be wired in parallel for the best results and sound.
  • There are a few cases where certain types of speakers can be used in series without hurting sound quality (or other disadvantages).
  • Before wiring speakers in parallel, it’s important to be sure you pay attention to your stereo or amplifier’s minimum Ohms rating.

The main thing to remember is that there’s a list of reasons why you don’t want to use most speakers in series – all of which I’ll explain in more detail as we go.

What sounds better parallel or series wiring?

parallel vs series speaker wiring sound quality problems diagram

When it comes to sound quality you may not be aware of it but parallel speakers maintain their sound quality while series connected speakers can have a bad or “odd” sound.

That’s because many coaxial speakers as well as 2-way or 3-way speaker cabinets or car speaker systems use speaker crossovers in their design. Speaker crossovers are used to block unwanted sound frequencies from reaching speakers that aren’t well suited for them.

For example, tweeters can’t handle low bass or midrange as it causes terrible distortion and even damage. Woofers or midrange speakers, similarly, cannot produce treble (high frequencies) well and sound poor. When combined, crossovers create a better-sounding speaker system that gets the best performance from them.

How series resistance affects crossovers

Crossovers (electrical components called capacitors and inductors) block sound based on a particular speaker load resistance in Ohms. When that speaker load is changed, something called crossover shift occurs. 

This means that the crossover frequency changes greatly, allowing unwanted sound to pass to a speaker or speakers. Knowing this you can understand why series-connected speakers can have poor sound: you’re connecting more speaker load (Ohms) than should be used.

It’s also adding extra capacitance and inductance in series and parallel that can cause some odd problems I won’t go into here. That’ll affect the sound as well.

Note that there is an exception to this and you can use some types of speakers in series without any noticeable sound quality problems. (I’ll explain more later)

Are speakers louder in series or parallel? What about power?

series vs parallel speakers power and volume explained diagram

As a general rule, parallel speakers are louder than series speakers. That’s because:

  1. Wiring speakers in series increases the total speaker impedance (Ohms) load, decreasing how much electrical current (amps) can flow. This means the amp or stereo’s power output will be lower.
  2. Series speakers receive a portion of the power delivered and won’t be driven as much as parallel speakers.

Note that this is the normal situation when you’re using speakers rated for the amp or stereo you have. It’s a different case when purposely using lower impedance speakers in order to add keep the total speaker load low.

I’ll explain what I mean below.

Does series or parallel give more power?

As I mentioned above, wiring speakers in series means (in most cases) that you will be increasing the total speaker load above that recommended for the amplifier, receiver, car amp, etc. There’s nothing harmful about having the total Ohms load be higher but it comes with a price when it comes to power.

For example, let’s say you have an amplifier with the following power specs:

  • RMS power @ 4 Ohms: 100W/channel
  • RMS power @ 2 Ohms: 200W/channel

If you were to wire two 4Ω speakers in series you’d have 4Ω + 4Ω = 8Ω total. This means that:

  • The total power output to the 8 ohm series speaker load would be only 50W maximum.
  • The total power would be divided between however many speakers you have. In this case, that’s 50W/2 = 25 watts per speaker.
  • Each 4Ω speaker would have only 1/4 of the 4 Ohm power rating (100W) available to it meaning the volume will be a few times lower also.

As you can see, wiring speakers in series decreases the total power, the power to each speaker, and also the volume to each speaker.

Cases where series speaker wiring doesn’t have less volume

It is possible to purposely wire speakers in series to get the same power output from a stereo or amp. Taking our same example from above, we could do this:

  • We can wire two 2Ω speakers in series for a total of 4Ω.
  • The amp would still deliver up to its rated power at 4 Ohms (100W).
  • The power to each speaker would be 1/2 of that, or 50W each.
  • Each speaker will have 3 decibels (dB) lower volume than one 4Ω, but since they’re in series the volume would be the same as one speaker. 
Note: Speaker volume doesn’t add together like Ohms or other things. Doubling the power to a speaker (or using two speakers in series with 1/2 the power each of a single speaker) doesn’t double it – it increases it by 3dB due to how our hearing works.

That means two 50W speakers in series will have the same volume as a single speaker of the same impedance w/ 100W power.

Speaker Ohms for parallel vs series wiring

series vs parallel speaker ohms diagram

The important thing to understand about wiring speakers in series or parallel is the total speaker load (Ohms) must be equal to or higher than the minimum Ohms rating of the amp or stereo.

That’s because using multiple speakers in a way that drops the total Ohms (impedance, or resistance to the flow of electrical current in other words) will cause excessive current that can permanently damage an amp, receiver, or stereo. The electronics used in audio equipment has a limit that it can’t exceed.

Here are the basic rules to follow:

  • When speakers are connected in parallel the Ohms load divides by the number of speakers.
  • When connected in series the speaker Ohms add together.
  • It’s ok to use a higher total speaker Ohms load but not lower.

What type of speakers sound ok with series wiring?

diagram with examples of speakers that are ok to use in series for sound quality

There are some speakers you wire in series without sound quality problems. These are:

  • Single-cone midrange or single cone full range speakers (see the examples shown above) that don’t use a tweeter with crossover attached
  • Some horn tweeters (piezo tweeters, for example)
  • Subwoofers & woofers

These types don’t have crossover components that will affect the sound.

Although it’s true that speaker voice coils have some inductance due to their wound wire, it’s not much, and wiring these types of speakers in series works pretty well. However, be aware that any time you wire speakers in series both the total power delivered and power to each speaker will be lower because you’re changing the speaker load.

When wiring speakers in series the power and volume loss is a compromise you have to live with.

That being said, it’s still useful for different sound projects like a simple ceiling speaker setup, making a speaker array design, and some other unique designs. Also for amplifiers, receivers, or home stereos with lots of power available it’s less noticeable since they can make up the difference a bit.

Using regular speakers in series

You can also use regular single speakers such as tweeters or mids with a custom crossover designed for them. There are a few situations where this is handy or even necessary but it’s critical to do the math and use the correct crossover components since the total speaker Ohms load will be higher.

Wiring speakers in parallel vs series – pros and cons

series vs parallel speakers pros cons section image

There are a few pros and cons I’ll summarize for you here, as while parallel speakers are generally the best choice sometimes series has advantages.

Parallel speaker pros & cons:

PROS:
  • Best for maximum power and volume
  • Best sound quality for most speakers
  • If one fails, others will still have sound
CONS:
  • Not always possible due to the Ohms load
  • Harder to add extra speakers (min. Ohms required)
  • May require more amp channels etc.

Series speaker pros & cons:

PROS:
  • Higher series speaker Ohms safe for stereos & amps
  • Easy to hook up
  • Cheap, simple solution for ceiling speakers, speaker arrays, etc.
CONS:
  • Lower power & volume
  • Bad sound quality for 2-way or similar speakers
  • Lose sound to all speakers with a single failure point

One thing to bear in mind is that when a connection is lost with series speakers, all speakers lose sound since they’re no path for the electrical current to flow unlike parallel speakers.

Additionally, if series speakers are spaced apart it can be a bit of a hassle to connect them to each other.

Your comments are welcome.
  1. Let me rephrase the question can you put a 4-way crossover into series-parallel circuit via
    String one consist of four 8-inch Subs known as A, B, C, and D, and all 8-ohm
    String two is four 8-inch woofers known as E. F, G and H, and all 8-ohm
    String three is four 6-inch midranges known as I, J, K, and L, and all are 8-ohm
    String four is four 4-inch by 4-inch Horns known as M, N, O, and P, and all are 8-ohm. Wired in this fashion.

    String One: Positive power feed from Sub-woofer crossover is ran to Speaker A, then a Jumper wire from speaker A positive to speaker C positive, the negative side of Sub-woofer from crossover goes to Negative side of speaker D and a wire is ran from negative side of speaker D to negative side speaker B. Then a Wire is run from Negative side of Speaker A to positive side of speaker B, and the negative side of speaker C is run to positive side speaker D.

    String Two: Positive power feed from woofer crossover is ran to Speaker E, then a Jumper wire from E positive to G positive, then the negative side of woofer from crossover goes to Negative side of H and a wire is ran from negative side of H to negative side F. Then a Wire is run from Negative side of Speaker E to positive side of F, and the negative side of G is run to positive side of H.

    String Three: Positive power feed from midrange of crossover is run to Speaker I, then a Jumper wire from I positive to K positive, then the negative side of midrange from crossover goes to Negative side of L and a wire is run from negative side of L to negative side J. Then a Wire is run from Negative side of Speaker I to positive side of J, and the negative side of K is run to positive side of L.

    String Four: Positive power feed from Tweeter of crossover is run to Speaker M, then a Jumper wire from M positive to O positive, then the negative side of tweeter from crossover goes to Negative side of P and a wire is run from negative side of P to negative side P. Then a Wire is run from Negative side of Speaker M to positive side of N, and the negative side of O is run to positive side of P.

    Does that achieve 8-ohm across the crossover?
    And remember every speaker is 8-ohm to begin with

    Reply
    • Hello James. If the crossover was designed for 8Ω drivers, then yes you can do that since the series-parallel configurations (when you’re using 8 ohm drivers) will still equal 8Ω total each.

      The power to each speaker in that case will be 1/4 of the power delivered (1/2 x 1/2) but still add up the same. The net SPL(decibel) output of them can be different, however, although that’s a more complicated subject. It’ll definitely work, though.

      Best regards.

      Reply
  2. Loudness produced by a speaker connected to an amplifier is found to be inadequate. Another speaker is then connected in parallel to the first speaker in an attempt to improve the loudness. However, the loudness of the speakers is found to be even weaker. Carry out a study to determine the relationship between maximum -power delivered, the load resistance of the circuit and the internal resistance of a d.c. source.
    Hello sir, can you explain about this experiment and how to draw a diagram for this experiment ?

    Reply
    • Hello Vimalan. Well, maybe there’s some information missing..I’m not 100% clear. There are some things you *might* need to know:

      1. The speaker impedances.
      2. (Ideally) the amplifier power available, which can be used to solve for the max. amplifier voltage if needed for calculating power to a load.

      Amplifiers aren’t DC – they’re AC, so I’m not sure what the mention of a “DC source” is referring to. Audio amplifiers ideally have almost zero DC output.

      If you know the amplifier power and the load resistance/impedance you can calculate the power/current to each speaker and go from there. Best regards.

      Reply
  3. Is it ok to use an 8 ohm speaker in a 1973 radio that used an original 10 ohm? It’s really hard to find 10 ohm speakers. Would it be better if I added a 2 ohm resister if I can locate ant

    Reply
    • Hi Mike. I’m going to say that it’s most likely ok but it’s better to be careful. If it were me I’d monitor it for a few minutes to see if it begins to get very warm or hot, and if it does then yes I’d add ~2Ω or so resistance.

      Best regards.

      Reply
  4. Hi, I have 2, 8 ohm, JBL D140 15 in speakers from the 70s.
    From what I have read, they were rated at 75 watts RMS each.
    I want to use them in a 70’s sunn amp that is rated 300 watts at 4 ohms.
    I don’t want to blow the speakers, so what would be the best way to wire them up.
    I know parallel would match them to 4 ohms, but I don’t understand the power and sound dynamics.

    Reply
    • Hi Robert. Ok, so basically the power rating of the amp at 4 ohms will not be the same as 8 ohms. In this case we don’t have to try and get a 4 ohm load. The power at 8 ohms should be 150W, which is still more than your speakers can handle, so you can use one per channel at 8 ohms.

      However, if you’re worried about blowing them use a speaker fuse/protector of the correct rating to avoid blowing the JBLs. Based on the Sunn amp that would be a fuse with a rating of around 2 amps (I got 2.16A with my math). Slightly less if you want to be more conservative with it.

      Basically the speaker load (Ohms rating) affects how much current flows from the amp and therefore how much power can be delivered at full output. Knowing that we can figure out the current at whatever power we want to limit the speakers to (~75W in this case). A fuse/speaker protector will open when it hits that limit and prevent more power from being driven to the speakers.

      Reply
    • Robert,

      This tube amp, even though rated at 300W is actually able to pumps over 800W when pushed because this 6×6550 combined with its huge Power Supply is capable of moving mountains.

      I would NOT combine two vintage 75W speakers with such a monster.

      I would highly recommend however an Ampeg Portaflex which is a 50W tube amp and would carry these vintage speakers to heaven with an incredible full tube tone.

      Reply
  5. One major advantage for series in “simple” single speakers, like no extra components just speaker, is that since the power is lower, you can drive the speakers with more power to get higher overall sound. So you could use a powerful amp, connected to individually underrated speakers in series, and the total resistance will be higher. So each speaker will receive lower voltage individually. This would be useful if it’s easier to have an amp that has a higher output voltage output to a large speaker array than one that can just handle more current.

    Reply
  6. What a great article, i wish i would have researched this question out years ago. It answers the question of sound quality and volume when wiring new speakers or specking out new speakers to buy, one could potentially make many purchase blunders not knowing what your article teaches us today. Thank you!! one would think that a speaker manufacturer would want folks to know this info instead of living with their product with a compromised sound quality . The next thing i am going to read up on is understanding cross overs. I am building a home studio sound system, my wife and i are rookie drum and base guitar players and i like to put together music on CD’s and play it through the system , it has to sound great and have the volume to carry. Our house is good sized and amazingly sound proof meaning you can be cranked up down in the music room, travel upstairs in any of the back bedrooms and just barely hear it. It all seems to come down to power and how you use it because it make a huge difference!! Thanks again

    Reply
    • Hey there Kent and thanks for such an awesome comment! I’m extremely happy that you found my humble article helpful. :)

      > It all seems to come down to power and how you use it because it make a huge difference!!

      You’re absolutely right. It’s funny how much good sound you can get from even budget speakers and a modest amount of power if they’re used correctly. That was a hard lesson I learned when I was young, inexperienced with speakers & audio, and especially before I was an engineer.

      I’m really happy to hear you and your wife are sound/musically oriented and I respect your talent and ear for acoustics. That’s really cool.

      Side note: If you enter “crossovers” in the search box on my website you should find a handful of helpful articles I think will help you. Don’t hesitate to reach out if I can ever be of help. ;)
      Best regards!

      Reply
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