Help with Ohms equation

Discussion in 'Amps and Cabs' started by grantford, Jan 12, 2008.


  1. Jan 12, 2008 #1
    grantford

    grantford Member

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    8ohms amp into 8ohms cab = perfect

    8ohms amp into 16ohms cab = ok

    8ohms amp into 16ohms hotplate into 8 ohms cab = ???

    heat and smoke? what will happen???

    THanks!
     
    grantford, Jan 12, 2008
    grantford, Jan 12, 2008
    #1
  2. Jan 12, 2008 #2
    rockon1

    rockon1 Member

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    Dont really know. I have read that an attenuator can be straining enough even when its matched properly. With a load mismatch it sounds like it would be dangerous. Bob
     
    rockon1, Jan 12, 2008
    rockon1, Jan 12, 2008
    #2
  3. Jan 12, 2008 #3
    xray

    xray Gold Supporting Member

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    It should be fine. Lets say you are attenuated about half way to 8db or so. 50 % of your amps "sees" the 16 ohm load of the hotplate the other 50 % "sees" the correct 8 ohm load. Its never going to "see" more than 16 ohms and should be safe given that 16 ohms is safe to begin with.
     
    xray, Jan 12, 2008
    xray, Jan 12, 2008
    #3
  4. Jan 12, 2008 #4
    Ed DeGenaro

    Ed DeGenaro Supporting Member

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    8 into 16 into 8...fine
    8 into 8 into...fine
    8 into 4 into 8...not fine
     
    Ed DeGenaro, Jan 12, 2008
    Ed DeGenaro, Jan 12, 2008
    #4
  5. Jan 13, 2008 #5
    grantford

    grantford Member

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    Thanks Ed (and others):AOK
     
    grantford, Jan 13, 2008
    grantford, Jan 13, 2008
    #5
  6. Jan 13, 2008 #6
    freaksho

    freaksho Member

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    fwiw, the THD Hotplate manual specifically states not to mismatch at all.
     
    freaksho, Jan 13, 2008
    freaksho, Jan 13, 2008
    #6
  7. Jan 13, 2008 #7
    trazan

    trazan Member

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    Would any of these be preferred:

    4 into 8 into 4

    or

    8 into 8 into 4

    ?
     
    trazan, Jan 13, 2008
    trazan, Jan 13, 2008
    #7
  8. Jan 13, 2008 #8
    grantford

    grantford Member

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    Yeah I saw that too. I do however trust Ed D. with his experience with THD.:BEER
     
    grantford, Jan 13, 2008
    grantford, Jan 13, 2008
    #8
  9. Jan 13, 2008 #9
    bluto0251

    bluto0251 Member

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    What about 4 into 8 into 8

    The 4 being a bandmaster reverb
     
    bluto0251, Jan 13, 2008
    bluto0251, Jan 13, 2008
    #9

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