trying to get ohms right

Discussion in 'Speakers' started by victor.b, Nov 8, 2005.

  1. victor.b

    victor.b Auditioning

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    I have 3, 8ohm speakers. can someone tell me how to wire them on one channel and achieve an ohm between 8 and 16? thanks
     
  2. John S

    John S Producer

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    You generally would not want to do this...
    Can you elaborate some on your purpose?
     
  3. John Garcia

    John Garcia Executive Producer

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    You can wire two in series and that will give you 16, but there's no easy way to add the third and get where you want to be. The impedance isn't the only factor there though, because you will still be drawing current to drive three speakers no matter how you wire them.
     
  4. David_Rivshin

    David_Rivshin Second Unit

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    You can wire two in parallel, and the third in series to those two, which will give you a total of 12 Ohm impedance. However, the third speaker will get twice the signal as the first two, which (if memory serves me) will make it 6dB louder.

    Picture:
    Code:
     
     /---- +S1- --- 
     A+ --< >--- +S3- -- 
     ---- +S2- ---/ | 
     | 
     A- ------------------------------/ 
     
     
  5. John Garcia

    John Garcia Executive Producer

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    You can get impedance matching volume controls or a IM speaker selector and you will have an 8 Ohm load at the receiver.
     
  6. victor.b

    victor.b Auditioning

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    well i'm installing a new system for a customer. they have speakers already installed in the ceilings. i am installing a reciever that runs 8 ohms and she had 3 speakers in the master bedroom. I was just making sure i didn't make a math error in figuring ohms, i didn't think it could be wired. thanks
     
  7. David_Rivshin

    David_Rivshin Second Unit

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    If this is a pre-existing background music system then make sure the speakers aren't the 70V type. I don't know much about such systems, other than they need some special electronics or transformers to make them work. I believe Niles makes such things, and might have info on their website.

    BTW, I'd expect that if you just wired all the speakers up in series to get overall 24 Ohm impedance that everything work work just fine. Of course I've never tried something like that, but I can't think of any reason it wouldn't work for low-volume settings.

    -- Dave
     

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