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W3-881sjf filter below 100 hz

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  • W3-881sjf filter below 100 hz

    Hi everyone, i have the tangband w3-881sjf. I want to use it for my portable boombox but came to the conclusion that low bass let the speaker exceed his xmax by 6 times.

    Now i want to cut off the frequencys below 100 hz and if possible also use crossover at 8000hz to use a tweeter. The reason i want to cut it off that low is because my subwoofer don't play nice above 120hz.

    I use a 2.1 amplifierboard (tpa3116d2). Does anyone have suggestions???

    Greetings

  • #2
    Maybe i can use this, but without the subwoofer channel so i have 100 hz to 8000 hz for the mids en 8000 hz and above for the tweeter.

    Also i don't understand the wiring of the circuits. It seems to me that i use 2 times the power compared to just use a full- range without crossovers?

    Thanks

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    • #3
      Anyone?? 😮

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      • #4
        Looks to me like that driver exceeds its limited Xmax (0.5 mm) w/just 1 watt when pushed below 200Hz.

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        • #5
          Anyone know how to highpass this speaker from 100hz

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          • #6
            Probably easiest to buy a handful of large NPE caps and experiment. Start with a 500uF.
            Don't listen to me - I have not sold any $150,000 speakers.

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            • #7
              This is what you need to do it passively:
              First, you need to flatten the impedance peak at Fs - so a "normal"-ish 2nd order filter has a chance to work for you.
              Across the W3's terminals (so, in parallel with the driver), you need to string these 3 components in series: a 12ohm resistor, Dayton's 10mH "iron core" (# 257-580), and a 200uF npe cap - at a cost near $15.
              Then THIS 2nd order filter will work pretty well: a 125uF npe series cap, and PE's 8mH iron coil - in "shunt" (to ground). (About $11 more.)
              Total cost to passively roll off bottom (near 100Hz) is around $26 - about what the driver cost.

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              • #8
                Thanks for the info. I think i go for the parts express 100hz high pass filter (the easy way) and hope it sounds good. I always can add a tweeter in the future so i asked the parts express tech team how to do that and this is what they said.


                You would use the high pass filter first, to limit the low end. Then go into a 2 way crossover network that will divide the frequencies at 8000 Hz for each, woofer and tweeter.

                The first filter will take care of the lows, the second will direct highs to the tweeter and the rest of the lows to the woofer.

                Sincerely,
                Greg
                Technical Support Team


                Before this i have ask a lot on forums how to do this and they said it is to difficult but now parts express tech forum came with this answer. Have anyone suggestions how to do this

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                • #9
                  #266-462 100Hz 8ohm high pass
                  Here's the simulated output at various freqs. Unfortunately, between 85-155Hz it'll actually drive your W3 a bit harder, a LOT harder @ 105Hz.
                  BASICALLY is leaves the output alone at 400Hz and above, below that, here's what you'll end up with:
                  Freq. SPL WITH/100Hz filter
                  300 85dB 84dB (-1dB down)
                  200 83dB 82 (-1 down)
                  100 78dB 85 (THIS is UP +7dB, NOT really what you're looking for!) - it actually peaks at +9dB @ 106Hz
                  80 76dB 73 (-3dB down) - @ 86Hz, both outputs are the same
                  60 73dB 63 (-10dB down)

                  The 2nd order filter I calc'd for you was only $11 (and works better). W/EITHER one you still need the ($15) RLC filter across the woofer's terms to flatten the Z-peak at Fs, to get it to roll off the way you want.

                  Comment


                  • #10
                    Originally posted by Chris Roemer View Post
                    #266-462 100Hz 8ohm high pass
                    Here's the simulated output at various freqs. Unfortunately, between 85-155Hz it'll actually drive your W3 a bit harder, a LOT harder @ 105Hz.
                    BASICALLY is leaves the output alone at 400Hz and above, below that, here's what you'll end up with:
                    Freq. SPL WITH/100Hz filter
                    300 85dB 84dB (-1dB down)
                    200 83dB 82 (-1 down)
                    100 78dB 85 (THIS is UP +7dB, NOT really what you're looking for!) - it actually peaks at +9dB @ 106Hz
                    80 76dB 73 (-3dB down) - @ 86Hz, both outputs are the same
                    60 73dB 63 (-10dB down)

                    The 2nd order filter I calc'd for you was only $11 (and works better). W/EITHER one you still need the ($15) RLC filter across the woofer's terms to flatten the Z-peak at Fs, to get it to roll off the way you want.
                    Thanks, i really apriciate it. I have drawn it on paper to show if i do it the right way. I have search for 12 ohm resistor but only could find 12.5 ohm resistor. Also i have search for iron coil but came to 8mH iron core.

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                    • #11
                      you said by 100hz it goes from 78db to 85db but it seems good to me because the overall spl off the speaker is 88db so in that way more flatlined.

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                      • #12
                        Your part #s are all good, but your dwg isn't quite right.
                        The RLC (3-element) "string" doesn't hook across the amp's terms, it hooks directly across the woofer's terms (polarity of the string (or any individual components) makes no difference).
                        The 125uF cap runs directly between one of the amp's terms (pol. doesn't matter) and one of the woofer's terms (again - there's no polarity).
                        The 8mH coil ALSO runs directly across the woofer's terms (so . . . technically, it's in parallel w/the 3-el string).

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                        • #13
                          Yeah, but your entire issue w/this design is that your woofers are distorting like mad at 100Hz 'cause they don't have enough Xmax to do the job. Boosting their output at 100Hz is exactly the opposite of what you want to do.

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                          • #14
                            Originally posted by Chris Roemer View Post
                            Yeah, but your entire issue w/this design is that your woofers are distorting like mad at 100Hz 'cause they don't have enough Xmax to do the job. Boosting their output at 100Hz is exactly the opposite of what you want to do.
                            Yeah you are right! Do know if i also can put a tweeter with it (around 7500hz). Thanks 😁

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                            • #15
                              ???

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