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Jims 3 way speaker build

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  • Wolf
    replied
    If they get nasal in male vocals, pop a 20-30 ohm across the tweeter and see if it goes away.
    Wolf

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  • jimbones
    replied
    so this is the XO I have in play now. I had another listener come over to hear it and it sounds real nice. I think I need to pause and listen for a bit and pause making changes until I get real familiar with the speakers. Then I can refine further. One note the tweeter polarity should be shown as in phase. For some reason in the SIM the results are better reversed but in reality it is better In Phase
    Attached Files

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  • rpb
    commented on 's reply
    I would do the same, once I thought the padding was close. When you disconnect drivers, do so at the source of the signal, not at the driver. If the woofer is disconnected, and you take a gated measurement of the mid, and tweeter, it should be an easy measurement. Fine tune the mid to tweeter x-over if needed.

    A close mic on the mid will show you the roll-off. Same with the woofer. Measure the mid and woofer together from about 12" from a point half way between centers. Look for a deep null when the polarity of one driver is swapped. If you get a deep null, that means the drivers were in phase with the other polarity. Being close to the floor may screw this measurement up, but maybe not. You might want to plug the port for this measurement.

  • jimbones
    replied
    Originally posted by rpb View Post

    Smoother is not the goal, but getting a measurement of the driver without the room changing the response is.

    Can you elaborate on the needed tonal balance changes? Or describe the new tonal balance after yesterdays changes?
    what I am concentrating on is I take individuall response of each driver to see if there is excessive overlap and if they are playing in the range I expect them to. For example the mid was playing flat up to 4k before it even started to roll off. That is not what I wanted with a XO point of 2800hz. I made some value changes and they look now like they are are correct not I am playing with the padding on the tweeter and mid to make sure it is not too forward, dull, bright etc. Ill post XO soon

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  • rpb
    replied
    Originally posted by jimbones View Post

    I dont think it will but I will look it up. Also I was told not to use smoothing. I could make the curves smoother.
    Smoother is not the goal, but getting a measurement of the driver without the room changing the response is.

    Can you elaborate on the needed tonal balance changes? Or describe the new tonal balance after yesterdays changes?

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  • johnny5jz
    commented on 's reply
    There is a selection in Omnimic for a blended response which will show below 200hz. Your woofer response really stands out as not looking right.

  • jimbones
    replied
    Originally posted by rpb View Post
    I no very little about tube amps, but I'd use a tough solid state amp till you decide everything is like it should be.

    Have you listened to the speakers as a pair yet with this x-over? If so, how is the tonal balance, and bass? What music? I have several CDs that I usually start with, and if things are going well, I listen to quite a few tracks.
    I dont think it will but I will look it up. Also I was told not to use smoothing. I could make the curves smoother.

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  • DeZZar
    commented on 's reply
    Is this with or without crossover parts?

    I don't know what's going on with OmniMic but you can't get a sub 200Hz measurement gated to 3.5ms....so for the woofer we should not be seeing anything below 200hz...

  • rpb
    commented on 's reply
    Will your mic work with a computer sound card, and computer software? HOLM is free, and I believe much easier to see what's going on, because the measurements are smoother.

  • jimbones
    commented on 's reply
    bass is prominent with a hump in the 40's. the sound is very clear but mot balanced so I need to get the levels of each driver correct. I made some changes will test tomorrow. You any I are on the same page lol, I borrowed a SS amp for test purposes. It has promise I think this is where I sneak....

  • rpb
    replied
    I no very little about tube amps, but I'd use a tough solid state amp till you decide everything is like it should be.

    Have you listened to the speakers as a pair yet with this x-over? If so, how is the tonal balance, and bass? What music? I have several CDs that I usually start with, and if things are going well, I listen to quite a few tracks.

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  • jimbones
    replied
    ok so i followed suggestions to measure each individual driver 24 inches out on axis of each driver. Not so pretty.
    Attached Files

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  • jimbones
    replied
    so this is my system zma. Good thing is left and right match lol. So I have a couple of questions
    1) from the curve it looks like the port tuning is very low. Is that correct? seems very low. Fbox is 30 hz sounds right and Fwoofer is 50hz. Does anyone see any issues? Note that these speakers will be used with a tube amp so I am glad at least that it doesn't go super low.

    On another note I use the generator in dats and the strongest output is at 50hz. This causes that "one note bass". Is there any way to address it? Thanks
    Attached Files

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  • jimbones
    replied
    Update: I build crossover in post 235 minus the 3.3 up cap in the woofer LP and the 7.15mh is actually a 8.3mh, the 5.1 ohm is actually a 4 ohm and the only other change is I am using a 2mh coil instead of a 2.2mh as that was what I had in my parts bin. Its an OK starting point. Polarity for now is WMT, + - +. Ill look at the other suggestions and as rpb says sneak up on it. Oh and one other thing. Only one of the cabinets is stuffed so I have to do the other to match. I had done it on one only as a test.

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  • jimbones
    commented on 's reply
    Agree Dezzar. I didnt know that I am supposed to start by measuring each driver on axis. I will do that and save the files for when needed. This isnt my first project and I cant say how many revisions it takes to get right but its a lot lol. Im with both of you on that. Its important that when I do something I understand the importance as you have so clearly explained.
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