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  1. #1
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    converting 4 ohms to 8 ohms how?

    I have a pair of speakers that have mismatched woofers, it's a long story and I will spare you all. The newer woofer is 8 ohms and the older woofer is 4. I'm planning to replace both, however in the mean time, if I add a 4 ohm resister to the + side of the 4 ohm speaker will my impedance become 8 ohms? My second question is whether I should even bother, my amp doesn't seem to have a problem running the two, I have one of those Yamaha 2500's, and it hasn't tripped the breaker... yet.

    Any opinions appreciated.

  2. #2
    asdf bjornb17's Avatar
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    i think if you connect a resistor as you described, half of the watts are goign to go to that resistor as cause a lot of heat problems. might not be very safe, but then again, im not really sure either.

  3. #3
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    ok. adding a 4 ohm resistor in series will give you an 8 ohm total load. the current will be the same in both the speaker and the resistor, but half the voltage will be dropped across the resistor and the other half across the speaker. power is found by the formula Power = Current x Voltage. this means that you would effectively have half your power dissipated in your resistor. there was another post about this sort of stuff, but based around lowering speaker resisitance. just as in that case, this is not a feasable approach. the only effective way would be to replace the woofer with an 8 ohm one.

    so in other words, just run it the way it is.

    -Jace

  4. #4
    Forum Regular N. Abstentia's Avatar
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    I did that once with a power resistor before I knew better...I just laid the resistor in the bottom of the enclosure. Lo and behold it got so hot that it burned a hole in the cabinet

    Replace the woofers asap.

  5. #5
    Loving This kexodusc's Avatar
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    Roflmao

    Quote Originally Posted by N. Abstentia
    I did that once with a power resistor before I knew better...I just laid the resistor in the bottom of the enclosure. Lo and behold it got so hot that it burned a hole in the cabinet

    Replace the woofers asap.
    That's okay, I fried a North Creek tweeter when I soldered it to the woofer output lugs on my crossover...The Peerless woofer seems fine though, coudn't figure out why I wasn't getting much sound out of the left speaker so I cranked up the volume a bit more and then shifted the balance left. Then a sound like a cap going off followed by ripped paper happened...pooof.

    To make matters worse, when I took it apart, I had the polarities between the drivers matched, when in fact the tweeter should have been in reverse...

    Moral of the story...some people have no business being inside speakers...lucky for me I ignored that lesson.

  6. #6
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    indeed. its good to ask someone before messing with stuff like that and even better to leave it alone if you dont know what your doing!

    -Jace

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