Resistor Question.

Discussion in 'Home Theater Projects' started by Brett DiMichele, Jun 5, 2003.

  1. Brett DiMichele

    Brett DiMichele Producer

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    Okay this is probably a stupid question but I may as well
    make sure...

    If you can not find the specific value of resistor can you
    gang two resistors together to arrive at the total value
    you need?
     
  2. John E Janowitz

    John E Janowitz Second Unit

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    Hi Brett,

    Yes, you can do this. If you're going to series resistors to come up with the value you need, then just pick any 2 values to get to the overal value you need. If you're going to parallel, then pick 2 resistors with equal values to get an equal voltage drop through each. For example two 4ohm in parallel gets you 2ohm overall. Also one 3ohm and one 6ohm in parallel gets you 2ohm overall, but you may risk burning up the 3ohm before the 6ohm.

    John
     
  3. Hank Frankenberg

    Hank Frankenberg Cinematographer

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    Brett, you sure can. Two or more resistors in series: add each resistor value to get the total resistance. For 2 parallel resistors, total resistance = 1 divided by the total of (1 divided by R1) + (1 divided by R2).
     
  4. Brett DiMichele

    Brett DiMichele Producer

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    Thanks fellas.. That's what I thought [​IMG]

    I never even thought about paralell though (duh to me..)
    I will stick with Series [​IMG]

    [​IMG]
     
  5. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    But remember before you series a hand full of resistors... The more components in your network, the more poop in your signal path (Even if it is high quality mills poop). [​IMG]

    Sorry I havn't been on aim in a while, I've been a busy bee. Keep us updated with operation upgrade AR9. [​IMG]
     
  6. Jeff Meininger

    Jeff Meininger Second Unit

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    Would three 12 ohm resistors in parallel yield a 4 ohm total?

    Also, as far as "poop factor" goes, which situation is preferable?
    1. Use three 10W audio grade resistors in series to achieve the desired ohm value with 30W power handling.
    2. Use three 10W audio grade resistors in parallel to achieve the desired ohm value with 30W power handling.
    3. Use a single sand cast / wire wound resistor for 25W power handling.

    The best sounding crossover I've ever designed (and I've only designed 3) used a single sand cast / wire wound resistor. But I haven't actually tried options 1 or 2... my other 2 crossover designs just use a single audio-grade resistor and have lower theoretical power handling.

    By the way, the fact that my 3rd crossover sounded the best was surely because it was my 3rd crossover and I've learned some stuff. Not attributing it to the restistors, just threw that out there to say that the madisound wire wound's don't automatically equal superpoop.
     
  7. Jonathan M

    Jonathan M Second Unit

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  8. Brett DiMichele

    Brett DiMichele Producer

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    For me I don't think it's the issue of a certain resistor
    sounding better. I am replacing the oem sand casts with
    Mills simply because we know the Mills *IS* a better resistor
    with a much tighter tolerance than the sand cast. The price
    isn't really that much higher for a mills vs a PE non inductive
    sand cast and the tolerance factor is much tighter. Anything
    you can do to make the whole crossovers tolerances closer
    to one another has to be a positive improvement.
     

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