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Question about ohms.

Discussion in 'Amps and Cabs [BG]' started by Fawkes007, Sep 30, 2005.


  1. Fawkes007

    Fawkes007

    Sep 13, 2005
    SF Bay Area
    My amp has a 4 ohm minimum.

    I have two 8 ohm cabs, with the jack sockets wired in parallel.

    Can I add a third 8 ohm cab IF I connect the amp to the cabs thusly:

    Amp =====Cab=====Cab
    I
    I
    I========Cab.


    Thanks. Hope you like the schematic.
     
  2. Kelly Lee

    Kelly Lee Yeah, I'm a guy! Supporting Member

    Feb 17, 2004
    Marana, AZ, USA
    Nope, that equals 2.67 ohms. Sorry.
     
  3. Fawkes, your amp is going to see the same load no matter how you wire them. First off, how many speakers are in each cabinet? There is a product made by Sherlock Audio called the Speaker Mate that has helped solve similar problems but I'm pretty sure it won't work in this situation.
    Look here:
    http://www.rainbowmusicshop.com/sherlock/home_wide.html
    http://www.rainbowmusicshop.com/sherlock/images/diagram R.gif
    *this ends up being the same total load as your diagram*
    (too low for your amp)

    One recent page I linked to from this forum is:

    http://www.colomar.com/Shavano/spkr_wiring.html

    As you can see, circuits tend to favor pairs so making these three cabinets work in the way you are suggesting is no small feat, if not downright impossible. If you'll notice about 3/4 the way down the 'colomar' page there's a diagram for three speakers.

    The diagram illustrates that you can run two 4 ohm speakers in series with each other, then they can be wired in parallel to an 8 ohm speaker to make a total load of 4 ohms. The next diagram shows what would happen if you double those values; two 8 ohm speakers in series, then wired parallel to one 16 ohm speaker, giving you a total of 8 ohms.

    So the short answer is: unless you can get an amp that's stable to 2 ohms, you're outta luck. Why doesn't every bass cab have AccuGroove's AccuSwitch feature? They should've started including this feature years ago. :crying:
     
  4. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    As others have written, you'd either need something like the Sherlock box or make or have made a custom speaker cable that connects two cabinets in series.

    What are the three cabinets, what amp are you using and where do you live?