Speaker Wiring Impedance Balancing

Discussion in 'The Workbench' started by Neil Cawley, Jun 6, 2021.

  1. Neil Cawley

    Neil Cawley Member

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    I thought I understood the basics of speaker wiring, parallel vs series and I was hooking up my speakers, but math is not agreeing with reality. I have two 8 ohm speakers and one 4 ohm. I wired the two 8 ohm speakers in parallel, then tied those to the 4 ohm in series (notice the sign change in the graphic). I expected the total impedance to be 8 ohms, but I measure 2 ohms.

    What am I missing?

    Speaker wiring.jpg
     
  2. Michael Roe

    Michael Roe Well-Known Member

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    All three are in parallel but the 4 ohm speaker is out of phase.
    You would need to run the first 4 ohm speaker and the 2nd middle 8 0hm in series.
     
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  3. Michael Roe

    Michael Roe Well-Known Member

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    From jack positive to "4 ohm" positive.
    From 4 ohm negative speaker to 8 ohm positive (middle speaker.
    From 8 ohm negative (middle speaker) to jack negative.
     
  4. Michael Roe

    Michael Roe Well-Known Member

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    Think of "Series" as power in and power out to next speaker.
     
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  5. Dogs of Doom

    Dogs of Doom >>> Moderator <<< Staff Member

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    Here's what you need to do:

    series.jpg
     
  6. Neil Cawley

    Neil Cawley Member

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    Thanks for the reply Michael, is the "jack" the hookup to the amp? I am still confused.
     
  7. Neil Cawley

    Neil Cawley Member

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    Ok that graphic popped in as I was answering, I will try that, interesting
     
  8. Dogs of Doom

    Dogs of Doom >>> Moderator <<< Staff Member

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    yeah, after I posted it, I thought, I should have added this text:

    series.jpg
     
  9. Michael Roe

    Michael Roe Well-Known Member

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    This is it...dogs drew the pic :)
     
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  10. Neil Cawley

    Neil Cawley Member

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    Dang you guys are smart! That works, I now have the 8 ohms. Thanks
     
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  11. Michael Roe

    Michael Roe Well-Known Member

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    The jack would be on the speaker cab jack that you would connect your amp speaker out to the cab input ( or jack).
     
  12. Michael Roe

    Michael Roe Well-Known Member

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    Not really, lol, just old and been there done that!
    Now, you pass it on!
     
  13. Dogs of Doom

    Dogs of Doom >>> Moderator <<< Staff Member

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    you've just got to remember, that to have series, you need a loop, as illustrated on the right ½ of my drawing. To be parallel, all +'s are connected together & all -'s together. The loop goes + to -, to + to -

    parallel:
    +/+/+
    -/-/-

    series
    +/-/+/-

    here, you have a mix, of series, w/ 2 of the speakers hooked up parallel.
     
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  14. Neil Cawley

    Neil Cawley Member

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    I wanted to close out this thread with the rest of the story. I have a Valvestate S80 (8240) combo and a stereo 412 cab I was putting together. The S80 did not come with speaker out jacks only DI jacks. I used the wiring in this thread and all works good. The combo and cab are wired as a stereo system. Very happy with my new practice amp.

    S80 Front.JPG S80 back.JPG
     
  15. shredless

    shredless Well-Known Member

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    Now we can discuss sensitivity and how much power each speaker will get
     
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