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4ohm vs 8+ohm speakers

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  • 4ohm vs 8+ohm speakers

    As I've written in other recent threads I am working on an MTM with Eclipse woofers and the satori tweeter. Currently they are in parallel with a minimum of 2.5ohm but otherwise 4ohm nominal. I have amps to drive them so that's not a concern. However, if I were to design them in SERIES, I would end up with minimum 9ohm in the woofers and 8ohm to the tweeter (Sim below).

    So let's say sensitivity is about ~88db for the parallel, would it be worth it to do series instead even though sensitivity will be much lower?
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  • #2
    My kind of default answer is - if the amp can handle it, go for it - but I tend to veer more towards the 8 ohm nominal range due to it being a bit easier on the amp.

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    • #3
      As you said, in parallel, you will have more sensitivity (a theoretical 6db). In series, you have a safer load to drive and less distortion from the amp, again in theory. If the amp has the power to give you the volume you want at 8ohm, imo, that is the way to go.
      https://www.facebook.com/Mosaic-Audi...7373763888294/

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      • #4
        Usualy when padding a tweeter you end up with a higher impedance in the high frequencies. You should be able to adjust resistor values to pad the tweeter with a raised impedance. With the lower impedance I would expect you have a rather small resistor value in your crossover, which will also have to dissipate some heat as a result. I would also worry a bit of the declining impedance towards the top octave, depending on your circuit this may end up as an electrical short above the audio range.

        That said, a low impedance in the high frequencies is much less of a concern than a low impedance at low frequencies.
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        "I just use off the shelf textbook filters designed for a resistor of 8 ohms with
        exactly a Fc 3K for both drivers, anybody can do it." -Xmax

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        • #5
          Thanks everyone. I suppose I'll give a go at rewiring for 8ohm and see what happens. Solder some coils together. Lord knows I've amassed plenty of caps and coils over the years, might as well put them to work. The eclipse woofer is so good. My favorite I've played with so far, and the only designs for them are both owned by Meniscus. Be nice to have at least one freely available. So maybe I'll do both a Parallel and Series thread.

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          • #6
            I designed and built a pair with the 4 ohm version of that woofer along with the RS28A. They were very nice. I'll look and see if I can find the crossover design.
            Craig

            I drive way too fast to worry about cholesterol.

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            • #7
              Originally posted by PWR RYD View Post
              I designed and built a pair with the 4 ohm version of that woofer along with the RS28A. They were very nice. I'll look and see if I can find the crossover design.
              That would be great. especially as it won't be long before the return of the RS28A...

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