Electrical engineering question: speakers

Discussion in 'Digital Audio' started by Sdashiki, Nov 30, 2006.

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  1. macrumors 68040

    Sdashiki

    Joined:
    Aug 11, 2005
    Location:
    Behind the lens
    #1
    I know this is a computer forum, but i also know there to be lots of electrically geared people on here, so I have a question many might be able to help with.


    I have two speakers that are 8 ohms, 150w RMS each.

    I have one channel on an amplifier rated at 300w RMS @ 4 ohm.

    Is it possible to wire these two speakers into this one channel so that both speakers "see" 150w and not the full 300w?

    thanks! :D :eek:
     
  2. macrumors 6502a

    elfin buddy

    Joined:
    Sep 16, 2001
    Location:
    Tuttlingen, Germany
    #2
    Wire the two speakers in parallel and your amp will "see" a 4 ohm load. Since they should each be able to dissipate 150W, you should be able to use your amp to pump out 300W without blowing them.

    I'm not overly familiar with speaker technology, but I think you'll only get mono sound out of them.

    Oh, and I'm not warranting that this will work. I assume no responsibility if you wreck your speakers.
     
  3. thread starter macrumors 68040

    Sdashiki

    Joined:
    Aug 11, 2005
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    #3
    the basic question is thus:

    a single channel (mono +/- connections) outputs 300watts.

    2 speakers (whose wiring config equals 4ohms) wired to the one channel.

    do the speakers see the full 300 watts at each speaker, or half that, 150w?


    does wiring a mono channel between two (or more) speakers take the channels output and divide by the number of speakers?
     
  4. macrumors 6502a

    elfin buddy

    Joined:
    Sep 16, 2001
    Location:
    Tuttlingen, Germany
    #4
    If each of the speakers took 300W, then your amp would have to be outputting 600W, which it won't do.

    If both speakers are identical, then the current coming out of the amp will be evenly split between both speakers in a parallel configuration. Since P = I^2 x R, at 300W and a 4 ohm load, I = 8.66A coming out from the amp at max power. That means each speaker branch takes I/2 = 4.33A. Power dissipated by a speaker is also P = I^2 x R. I = 4.33A, R = 8 ohm, so P = 150W for each speaker.

    Hence, I think wiring them in parallel will make them work the way you want.
     
  5. Moderator emeritus

    Rower_CPU

    Joined:
    Oct 5, 2001
    Location:
    San Diego, CA
    #5
    Thread closed due to bumping/rudeness.
     
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