SPEAKER WIRING

Discussion in 'Cabinets & Speakers' started by Guv'nor, Nov 2, 2006.

  1. damuncha

    damuncha New Member

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    Hello

    I was wondering if I can get some help please confirming a couple of things.

    I have an angled 4x12 cabinet labeled JCM 800 lead series. There are two inputs on the back. Is this normal?

    If so, how would the two inputs be used? Surely not to two amps?

    This is how the speaker jacks are wired
    Image_1.png

    Secondly, from looking at the wiring it looks to be wired Parallel/Series. Can you confirm this please? It's making my head spin!

    Here's my hand drawn diagram:
    Image.png
     
  2. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    The cabinet has a single cup/jack in that case. It was modified.

    That is Series-Parallel. But each set of two is placed in series and then the two are paralleled at the jack.

    It was probably done to run a speaker cable from that cabinet to the next for paralleling cabinets or to run two speaker cables from an amplifier's output jacks to the two jacks in the cabinet for better cable/connection power handling to a single cabinet.
     
    Last edited: Jul 11, 2017
  3. damuncha

    damuncha New Member

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    Thanks for that. So for two cables going from the amp to the cab I'm assuming that you would keep the amp set to 16ohms. The speakers are all 16ohm.

    I was doing a bit more searching online last night and found this diagram:

    [​IMG]

    That to me seems to most closely match what I have in the cab.

    This is their diagram for series parallel:
    [​IMG]

    I just wanted to double check if it's Series/parallel or parallel/series.

    Sorry for the dumb questions. I usually just plug in and go but I wanted to try and learn more about my kit.
     
  4. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    Ha, ha. It just looks different somehow to you.

    Actually and I hate to crap on a parade but both of those Scumback diagrams are actually series sets paralleled at the jack or source. You have to look closely. They are just drawn differently. The electrical connections of the two diagrams provide the same situation.

    I know Scumback is a sponsor here, the guy is a member and lots of people like Scumbacks. I have seen these diagrams posted here before and no one ever commented on them or even noticed I guess that I remember. So I am commenting.

    For information: in electronics there are series, parallel and series-parallel circuits. There is nothing called parallel-series. There are however deviants of series-parallel which include strings, branches and banks or whatever and so on.

    So paralleled speaker sets placed in series at the jack would still be a series-parallel circuit with two banks of paralleled resistance place in series with the source. (#1 below) That is not happening in that first diagram.

    Likewise as mentioned earlier, series speaker sets placed in parallel at the jack would still be series-parallel circuit with two branches/strings of series resistance placed in parallel with the source. (#2 below)

    I found this on the net and think this may look simpler.
    upload_2017-7-11_23-23-22.png
     
    Last edited: Jul 11, 2017
    BowerR64 likes this.
  5. danfrank

    danfrank Well-Known Member

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    Which one is supposed to sound better? #2? I know a lot of people think one is better than the other, sound wise...
     
  6. Scumback Speakers

    Scumback Speakers Well-Known Member Sponsor

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    mickeydg5: I hate to rain on your parade, but Celestion thinks so. Those diagrams are just updated, easier to read versions of the diagrams they have on their site, and those are the wiring diagram names they use.

    I'm not saying Celestion knows everything, but since I provide these diagrams to help people rewire their old (pre stereo switch) cabs, I used the naming convention that Celestion used so that people knew what they had.

    If it's wrong, well, ok...but it's not my doing that it's named that way, I was just duplicating their wiring names for simplicity for others who know them as those names.

    Not taking it personally, so no harm, no foul, but let's give credit where it's due, ok? LOL
     
  7. Scumback Speakers

    Scumback Speakers Well-Known Member Sponsor

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    Using the Celestion diagram name, the parallel/series wiring has more midrange attack/bite, while the series/parallel wiring is more laid back and vintage sounding. Electrically they're the same thing, soundwise, they are different.
     
  8. Scumback Speakers

    Scumback Speakers Well-Known Member Sponsor

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  9. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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    4x12-series-par-wiring_4.png 4x12-par-series-wiring_4.png

    The red boxes represent a series. In the 1st drawing, you can see that there are 2 series connections side-by-side. In the 2nd the 2 series are paired top/bottom...

    The +, from the top left speaker, runs to bottom left +, which makes the parallel from the jack. The -, from top right goes to - bottom right...
     
    Last edited: Aug 8, 2017
  10. danfrank

    danfrank Well-Known Member

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    OK, so which one has more midrange attack/bite and which one is more vintage sounding, referring to the diagram MD5 provided in post #324. Sorry but the Celestion page doesn't work for me...
     
  11. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    I do not think one will sound better than the other if using 4 of the same speakers. All speakers will get the same basic voltage and current so therefore same power.

    A mixed set of speakers in a 4x12 will have more variances.
     
  12. danfrank

    danfrank Well-Known Member

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    OK, Thank you. The physics of it would say that both ways should sound the same.
     
  13. decoder

    decoder New Member

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    Hi

    I just bought a 1973 JMP 50 (1989) watt head and Im looking at getting a 2x12 with greenbacks, what Ohm speakers do I need?

    Thanks:)
     
  14. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    You should have a choice of output impedance for 16, 8 and 4 ohms.
    With a 2x12 there are generally three options with guitar speakers:
    two 16 (or 15) ohm speakers in parallel for 8 ohm output
    two 8 ohm speakers in series for 16 ohm output
    two 8 ohm speakers in parallel for 4 ohm output
     
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  15. decoder

    decoder New Member

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    Thanks:) So either 16 or 8 ohm would be ok. Great.
     
  16. decoder

    decoder New Member

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    hi. i have bought a 2x12 cab devoid of its speakers. i want to install a single 8ohm creamback ive bought and see how this one speaker sounds in the large cab. there the jack on tge back panel with a pair of cables soldered to it, can i just attach these to the creamback and set my head to 8ohm?

    thanks
     
  17. decoder

    decoder New Member

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    heres how it looks. thanks
     

    Attached Files:

  18. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    One 8 ohm speaker connected to the 8 ohm amplifier output is good.

    If you have a meter check the resistance at the plug on the other end of the speaker cable once connected to the cabinet jack. It should read somewhere under 8 ohms resistance.
     
  19. decoder

    decoder New Member

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    thanks. i just wasnt sure if the series/parallel thing happened inside the jack (pre wired so to say) or is something thats done after the jack. i didnt want to attach a single 8 ohm speaker to a jack that was wired for parallel for instance. i kniw nothing about this, as you can see
     
  20. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    The wiring/power flow make it either series or parallel. With one single coil speaker the only choice is series.
     
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