Ohms Question?

Discussion in 'Speakers & Subwoofers' started by Tom McDonald, Jan 1, 2004.

  1. Tom McDonald

    Tom McDonald Stunt Coordinator

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    I'm abit confused by the ohm issue, could someone please in non technical terms explain to me what difference 4 ohm speakers have with 8 ohm speakers and if sonically there is a big difference. I hope this is not a stupid question I just need to be enlightened by what Ohms really mean since I am considering upgrading soon and want to get the best bang for my buck, thanks.
     
  2. John F. Palacio

    John F. Palacio Supporting Actor

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    OHM is a unit used to indicate electrical resistance. It has nothing to do with the sonic qualities of a speaker.

    In a solid state, transformerless amplifier this means that more power will be delivered to a lower impedance loudspeaker.

    Again, this means little because speaker efficiency (acoustical power out vs electrical power in) is not accounted for.

    Lower impedances tend to place greater demands in power amps (again, tranformerless designs) so one must make sure that a given amp can handle the load. Speaker impedance ratings are of the "nominal" variety meaning that is sort of an average rating as it varies with frequency.

    Hope this helps.
     
  3. Ian-Fl

    Ian-Fl Second Unit

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    Something I look at is the sensitivity of a speaker. If a speaker is rated at 86db it will require twice the power to drive them than a sensitivity of 88db. So if you have a entry level receiver you'll want to go for speakers greater than 88 db. The same happens with ohms. A 4 ohm rated speaker requires more power than a 8 ohm speaker.
     
  4. Shane Martin

    Shane Martin Producer

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    Correct don't focus so much on the Ohms as much as the sensitivity. My 4 ohm speakers are 104db efficient. It doesn't take much to make them go loud.
     
  5. John F. Palacio

    John F. Palacio Supporting Actor

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    Not quite. A 4 ohm speaker DRAWS more power form the receiver. But it does NOT REQUIRE more power. Power requirements are based on efficiency and room volume/acoustics.
     
  6. Tom McDonald

    Tom McDonald Stunt Coordinator

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    Thanks guys for explaining things to me in a way I can understand and is useful knowledge.[​IMG]
     

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