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Jims 3 way speaker build

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  • rpb
    replied
    The impedance gets dangerously low at high frequencies. There's a straight path to ground through C3, and C1.

    Add a resistor in series with C3, and see how that looks. I can't sim that added resistor in PCD. I'd add about 3 to 6 ohms, and see how it looks.

    I think we are using different frd files, but basically, your filter looks to be OK, but with a downward slope.

    Try bypassing your tweeter 5.1 ohm resistor with a 6 to 10uf cap.

    I have to go out for a while.

    Try this on the woofer. 8mH, 100uf and 1.5 ohms to ground, followed by 2mH. This is a 3rd order, but with a little resistance added.

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  • jimbones
    replied
    rpb this is a hybrid. I used your mid bandpass and used my LP and HP for woofer and tweeter. If you think this is at least a good starting point I am going to mock it up.
    Attached Files

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  • rpb
    replied
    Originally posted by jimbones View Post
    rpb, I got your points above. I think the setback values for the mid were 2.18 in and for the woofer 10.5 in. Thats the numbers I am using in my sim. I dont know how well XSim and WinPCD track. I;ll try to mimic yours so we are at least in the same place.
    I used about .75", and 3". I think the woofer might be closer to 4". I don't think the AC is ever behind the woofer, but I could be wrong. I make my x-overs by trial and error mostly, and don't give much thought to AC. I measure the response instead.

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  • jimbones
    replied
    rpb, I got your points above. I think the setback values for the mid were 2.18 in and for the woofer 10.5 in. Thats the numbers I am using in my sim. I dont know how well XSim and WinPCD track. I;ll try to mimic yours so we are at least in the same place.

    Leave a comment:


  • rpb
    replied
    I added too many comments in the post above. You may have to click on the top right corner to see some of them.

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  • rpb
    commented on 's reply
    As you can see, how you pad a driver can change the xo parts needed. I was trying to get the final impedance up above 10 ohms for most of the frequency range. Not that it's a good idea, or anything, I just was trying to do it. You could try padding values using smaller resistors than I did, and see if it makes things easier, or harder,

  • rpb
    commented on 's reply
    I lifted the top end by bypassing some of the tweeter resistor padding with a 5uf cap. Or was it 12uf? I forget. Somewhere in between maybe.

  • rpb
    commented on 's reply
    You should add some resistance values for the coils in your sim. The ones I used were just made up. They can change the response slightly.

  • rpb
    commented on 's reply
    Try my mid xo with your woofer, and tweeter xo, and tweak things from there. I think I used the wrong tweeter file, as there was very little padding.
    My woofer filter was a damped 3rd order, but yours may work too. I made up my own offsets.

    On your filter, the bypass cap on the big coil is likely dropping the impedance at high frequency. Try adding a couple ohms in series with the cap.

  • DeZZar
    commented on 's reply
    Hmm...thats annoying. Mine still has File->Save As available.....I'll have to watch out for this patch!!

    I guess you can still just paste it into Paint and save it from there?

  • jimbones
    commented on 's reply
    I got the bandpass component for the mid what were your LP for tyhe woofer and HP for the tweeter. I am inputting them now to see if they match what your sim is.

  • rpb
    replied
    Padding the mid like I did, helped get the impedance up. The phase may not be as good as the sim shows, but that's not all that important. Ideally, you want to measure the actual response, but at low frequencies, it's difficult to get good measurements.

    Here's a sim without the big coil. It just requires the mid to work a little harder below 200hz. Likely not a problem.

    Click image for larger version

Name:	Jims speaker budget xo.jpg
Views:	124
Size:	273.9 KB
ID:	1493062

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  • rpb
    replied
    Click image for larger version  Name:	Jims speaker  nulls.jpg Views:	0 Size:	193.6 KB ID:	1493060 Here's the mid filter. There's likely a less expensive way to do this, but this looked better in the sim.

    Click image for larger version  Name:	Jims speakermid filter.jpg Views:	0 Size:	269.3 KB ID:	1493058
    Last edited by rpb; 11-24-2022, 09:18 PM.

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  • jimbones
    replied
    Originally posted by rpb View Post
    I'm not sure if I used the right files, but here's what I came up with.

    Click image for larger version Name:	Jims speaker.jpg Views:	0 Size:	187.5 KB ID:	1493052 Click image for larger version

Name:	Jims speaker impedance.jpg
Views:	118
Size:	232.0 KB
ID:	1493053
    Wow thats nice do you have the schematic to compare with mine? I like your idea of "sneaking up" so my idea is to get something I can listen to and make improvements or shall I say refinements along the way, Eventually I would like to understand about more than flat frequency response but phase response. Thats the advanced class. Thank you to all for your help.

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  • jimbones
    replied
    ​[ATTACH=JSON]n1493055[/ATTACH]

    test

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