Series or Parallel Speakers – Which is Better?

Series or Parallel Speaker Wiring Inside

When building an amplifier cabinet, you have many different speaker and wiring options.  One wiring consideration is: series or parallel speakers – which is better?  There are pros and cons to each approach, and this brief tutorial will help you decide what is best for your project.

Series Speaker Wiring

To begin, we must understand what each of these wiring arrangements mean.  Series speaker wiring is used to connect all speakers in a chained sequence.  Here is an example with two speakers.

  • First, audio signal will exit the speaker jack of the guitar amp.
  • Next, signal will enter speaker 1 at the positive terminal and exit at the negative terminal.
  • The signal with then enter speaker 2 at the positive terminal and exit at the negative terminal.
  • Finally, the audio signal will return to the ground connection at the speaker jack on the amplifier.

Parallel Speaker Wiring

A parallel wiring arrangement works a bit differently.  Instead of one chained sequence, parallel wiring utilizes two separate, unchained audio paths.  Here is another example with two speakers.

  • As before, audio signal will exit the speaker jack of the guitar amp.
  • Next, signal will enter speaker 1 at the positive terminal and speaker 2 at the positive terminal simultaneously.
  • The signal will exit speaker 1 at the negative terminal and speaker 2 at the negative terminal simultaneously.
  • Finally, the audio signal will return to the ground connection at the speaker jack on the amplifier.

Series and Parallel Speaker Wiring

Why do Speaker Cabinets use Multiple Speakers?

In the early days of guitar amps, engineers faced an issue.  As guitarists demanded higher wattage amplifiers, the power handling of speakers needed to be increased as well.

At the time, speakers could only handle around 25 watts each.  Instead of having to design higher power handling speakers, multiple speakers were used.

There were then two different ways to configure multiple speakers, in series or parallel.  The reason you would use one or the other all comes down to impedance.  Guitarists also use more than one speaker in an amplifier for greater tonal possibilities.

What is Speaker Impedance?

In the world of electronics, speakers are classified as reactive loads.  Speakers exhibit a property called impedance which is similar (but not the same) as resistance.  For the purposes of this article, we will think of impedance working like resistance.

In basic terms, speakers resist or impede the audio signal that is flowing through them.  This impedance is measured in a unit called Ohms.  Typically, there are three common impedance values for speakers: 4,8, and 16 ohms, although others can be found as well.

Your guitar amplifier needs a specific impedance to work correctly and safely.  Therefore, the impedance of a speaker or speaker cabinet should always match the required output of an amplifier.

Measuring the Impedance of Multiple Speakers

When using multiple speakers, the total impedance of the speaker network changes.  When speakers are wired in series, their individual impedance values add together to create one total impedance.  For example:

If two 8 ohm speakers are wired in series, the total impedance will be 16 ohms.  When speakers are wired in parallel, the total impedance will be one speaker’s impedance divided by the number of speakers.  For example: If two 8 ohm speakers are wired in parallel, the total impedance will be 4 ohms.

(Special note: this calculation for parallel speakers only works when the speakers are all the same impedance value.)

Series-Parallel Speaker Wiring

There is another special wiring arrangement where speakers are wired in both series and parallel.  This is used in most 4×12 speaker cabinets.  It begins by wiring one pair of speakers in series and the other pair of speakers in series as well.  Then, the two pairs are wired in parallel.  When this is done, the final cabinet impedance is the same value as one single speaker’s impedance.

For example:

  • You first begin with four 16 ohm speakers.
  • Then, wire one pair in series and the separate pair in series as well.  Each pair of speakers is now 32 ohms total.
  • Next, wire both pairs in parallel with each other.  This will take each network’s total impedance and divide it by the number of networks.
  • Finally, the complete speaker cabinet will have an impedance of 16 ohms.  This is the same impedance value of each original speaker.

Should You Use Series or Parallel Wiring?

The two wiring methods are used depending on your needs.  There is no right answer.

If you already own two 8 ohm speakers, and your amp only has a 16 ohm output, then series is the best choice.  Alternatively, if your amp only has a 4 ohm output, parallel wiring is the way to go.  Both options are good depending on the task at hand.

Do Series and Parallel Speaker Wiring Sound Different?

Technically yes, but at an extremely subtle level.  Part of the fun of playing guitar is experimenting with different aspects of your signal chain to create new sounds.

If you have found out that series wiring gives you the tone you’ve been searching for, that’s great!  Use it.  If you find out that wiring styles make no difference, that’s perfectly fine too.

Not only can you experiment with wiring styles, but you can also try different speaker cabinet loads as well (if your guitar amp output permits.)  Some people love specific speaker impedance values, while others find they make no difference on their guitar tone.  As long as you insure your amp and speaker loads are operating correctly and safely, have fun seeing what works best for you!

Combining Different Speakers

Continuing the idea of experimentation, there are endless tonal possibilities when combining different speakers.  If you have a speaker cabinet with two or four speakers, you owe it to yourself to experiment with different speakers to achieve that perfect tone.

As long as you abide by the impedance matching rules, amazing sounds can come from combining different speaker types.  In fact, many current boutique guitar amplifier builders do this exact thing in their amps to help achieve their custom sound.

This certainly doesn’t mean you have to use two different speakers.  You may find that using identical speakers in our amplifier cabinet is perfect.  Heck, you may decide that one single speaker is the right sound for your guitar.  It’s all about personal preference!

Conclusion

Series or parallel speaker wiring schemes are great tools for guitarists.  They allow us to achieve various impedance values to ensure our rigs are running safe.  They also allow us to achieve many different tones and have fun experimenting.

I hope this article has helped understand the differences between series and parallel wiring for guitar amplifier cabinets and has increased your curiosity for trying each wiring type out for yourself.  Happy Playing!

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