Question about parallel resistors

nduitch
nduitch Posts: 316
edited May 2013 in DIY, Mods & Tweaks
I have two 1 Ohm resistors in parallel, why does my VOM still read it as 1 Ohm?
Post edited by nduitch on
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  • Face
    Face Posts: 14,340
    edited May 2013
    They could be out of spec.

    http://www.1728.org/resistrs.htm
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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  • nduitch
    nduitch Posts: 316
    edited May 2013
    According to that calculator, 2 x 1ohm resistors in parallel is 1 ohm. So that changes a lot in all those crossovers using 2 x 1ohm mundorf mox resistors in place of a 2 ohm resistor, if that is true.
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  • blairfrischx
    blairfrischx Posts: 259
    edited May 2013
    How did you get the calculator to spit out 1 ohm for two 1-ohm resistors in parallel? It [correctly] says 0.5 ohm for me.

    Crossovers using two 1-ohm resistors in place of a 2-ohm resistor would have them in series.
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  • nduitch
    nduitch Posts: 316
    edited May 2013
    Yes, 0.5 correct.

    blairfrischx wrote: »
    How did you get the calculator to spit out 1 ohm for two 1-ohm resistors in parallel? It [correctly] says 0.5 ohm for me.

    Crossovers using two 1-ohm resistors in place of a 2-ohm resistor would have them in series.
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  • Face
    Face Posts: 14,340
    edited May 2013
    nduitch wrote: »
    According to that calculator, 2 x 1ohm resistors in parallel is 1 ohm. So that changes a lot in all those crossovers using 2 x 1ohm mundorf mox resistors in place of a 2 ohm resistor, if that is true.
    What crossover is this?
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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  • Face
    Face Posts: 14,340
    edited May 2013
    Depending on where it is in the crossover, it may or may not make a significant difference. If it's in the parallel leg of a woofer crossover, before or after a cap, it will affect the woofer's roll off on the top end. Changing out to a smaller value will affect the woofer's top end roll off, making it roll off sooner. This may affect phase integration, possibly create a small hole or dip in response, and maybe even lower distortion. In other words, it may not do anything offensive and require a change, but I would need to see what speaker, and where in the crossover this value exists to confirm.
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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  • Phasewolf
    Phasewolf Posts: 514
    edited May 2013
    The leads of your DMM may add some resistance to what you measure good leads cost a lot and so does a a accurate DMM what are you using and when is the last time you sent it out to be calibrated?
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  • nduitch
    nduitch Posts: 316
    edited May 2013
    I had the resistors wired in parallel, thinking they would double up. I wired them in series and the value is much closer.
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