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Thread: Think We May Have a Keeper Here!!!

  1. #106
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    While I've covered all this many times before I'm glad to see you are finally getting it Zilch. I'm not real keen on your regurgitation of my past posts but at least you read them all in addition to all the books and AES journals I've suggested. And your last post presentation here is pretty damn decent. You're also coming across better I think. You seem to have killed off those "we" people that were loitering around in your shop which is a welcome relief. No more quick and dirty shenanigans it seems. One more request?

    Get CLIO up and running so we never have to see the orange RTA thingie again ok? There has to be someone out there who can whip a CPU together for you. Sell an LE15B to fund it. Those things are boat anchors.

    Or do you have a boat...




    The above post is the kind of post I've been looking for from you Zilch. I'm serious. You've towed the line dude.


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  2. #107
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    Quote Originally Posted by Zilch
    What's going on here?

    Taken together, the three approaches provide a means to assess crossover performance: Is it working according to design? Is the design appropriate for the task? Is it optimum?
    Appears to.

    Possibly but, see below.

    Is it?, see below

    It would appear to me that in the analysis, the woofer could still be crossed over a little higher. But I'm no expert.

  3. #108
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    Quote Originally Posted by Giskard
    You've towed the line dude.
    It's taken no small measure of dedication on your part, for sure. Thank you for that....

    BTW, what system are we lookin' at there?

    [Heh, heh....]

  4. #109
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    Quote Originally Posted by toddalin
    It would appear to me that in the analysis, the woofer could still be crossed over a little higher. But I'm no expert.
    Let me get mine built and CLIO running. The Zobel might be adjusted, if required, to accomplish that. I just don't have sufficient measurement resolution presently to make a determination.

    In general, I'd say you're good to go for now. It's working, it sounds decent; it's time for some serious listening.

    Maybe think about upgrading your measurement capabilities if you want to do more of this. It's all good clean fun....

  5. #110
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    Quote Originally Posted by Zilch
    Maybe think about upgrading your measurement capabilities if you want to do more of this. It's all good clean fun....
    Your 64-band Barringer seems nice. Do they offer just the analyzer portion at a cheaper cost? I don't really need an eq and actually took my two Yamaha 31-band units out of the system to reduce background noise.

  6. #111
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    The Behringer UltraCurve Pro DEQ2496 has certainly carried me a long way during the past year. It's not avalilable as RTA only, but the AutoEQ function is very useful as an analytical tool, even if you don't use it for actual EQ in your system. It tells you right away what (and how much) adjustment is needed to achieve any desired response curve.

    I consider it test equipment, not a system component.

    If you just want RTA, there's other options suggested in these forums.

    Note: The UltraCurve RTA is 61 bands, but its EQ is 31 (1/3 octave)....

  7. #112
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    Quote Originally Posted by Zilch
    The Behringer UltraCurve Pro DEQ2496 has certainly carried me a long way during the past year. It's not avalilable as RTA only, but the AutoEQ function is very useful as an analytical tool, even if you don't use it for actual EQ in your system. It tells you right away what (and how much) adjustment is needed to achieve any desired response curve.

    I consider it test equipment, not a system component.

    If you just want RTA, there's other options suggested in these forums.

    Note: The UltraCurve RTA is 61 bands, but its EQ is 31 (1/3 octave)....
    61 bands means that there is a band for every other note of the diatonic scale. Does anyone offer 122 bands. I wouldn't want any of my notes to feel left out.

  8. #113
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    Quote Originally Posted by toddalin
    I wouldn't want any of my notes to feel left out.
    There's an inherent smoothing in the averaging it does to display with 1/6 octave resolution. For looking at the general trends, it's plenty. As you can see in some frequency ranges, it's anybody's guess what's going on due to measurement methodology artifacts.

    The manual advises against attempting AutoEQ below 100 Hz, for example. It's just not giving real measurements below there in a standard setup, as you know from your nearfield testing experiments.

    In certain respects, I believe your 10-band RTA might be effectively used as a low-frequency measurement device. The bottom 6 bands are all below 1 kHz, no? Maybe try "in-box" testing per Small....

  9. #114
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    "Keeper" crossovers

    Completed per the parts list above, first tests on my system look quite good. This is in cascade configuration, but HF is connected before the MF variable L-Pad, i.e., after MF high pass and fixed L-Pad. Call it "cascode," maybe.

    http://audioheritage.org/vbulletin/s...6&postcount=62

    Note separate LF and MF/HF input (bridged here,) for potential biamp operation later, as desired.

    2407H on PT-F95
    2450JSL on 2380A
    2235H in 4507, two ports closed

    Per RTA used for balancing, it produces flat response (within +/- 2.5 dB) with HF at max (red), but that's too "hot" sounding. Both controls at mid postion shown gives more listenable green curve, HF -4 dB at 20 kHz.

    [Sounds mighty nice, BTW.... ]
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  10. #115
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    O.K., I need some guidance now on a preferred method for measuring voltage drives with CLIO. I have a dedicated amp set up with it now, so I'll also be able to generate MLS response curves using Todd's driver configuration as well as this one.

    I want to compare cascade, cascode, and standalone HF connections, about four different configurations for Todd and others. There are interactions here to document and analyze....

  11. #116
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    Quote Originally Posted by Zilch
    Completed per the parts list above, first tests on my system look quite good. This is in cascade configuration, but HF is connected before the MF variable L-Pad, i.e., after MF high pass and fixed L-Pad.

    2407H on PT-F95
    2450JSL on 2380A
    2235H in 4507, two ports closed

    Per RTA, it produces flat response with HF at max (red), but that's too "hot" sounding. Both controls at mid postion gives more listenable green curve, HF -4 dB.

    [Sounds mighty nice, BTW.... ]
    OK, stupid question off-topic:

    Why do you plug the top ports as opposed to the bottom ports? Wouldn't leaving the top ports open bring some bass up closer to the other drivers possibly resulting in a more coherent sound? Ever try it and listen for a difference?

    I recognize that bass frequencies are fairly omni-directional.

  12. #117
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    Quote Originally Posted by toddalin
    Why do you plug the top ports as opposed to the bottom ports?
    I believe having the ports closer to the floor takes better advantage of boundary effect to enhance the low bass they produce, but I have NO (ZIP, ZERO, ZILCH) substantiation of that to cite.

    Coherence would not come at the port frequencies; as you state, they are omni-directional. Generally speaking, having the ports below the woofer lets the radiation that matters in this respect originate closer to the mid/high drivers as they can be closer together.

    I can't do much about that with these boxes, but I am using them here because the L200 woofer is even further separated, down at the bottom of the box. The c/c distance presently is 17" to the 2380A; sitting on top of L200, it was 25" or more. These 4507's are more coherent sounding.

  13. #118
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    Quote Originally Posted by Zilch
    I recently read where that didn't work so well with L212.

    [Heh....]
    Yeah but why?

  14. #119
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    Quote Originally Posted by Giskard
    Yeah but why?
    Elimination of boundary effect, as I recall, resulting in incorporating an over-emphasized mid-bass. Let me go check before holding me to it, tho....

    Edit:

    http://www.audioheritage.org/html/pe...ives/smith.htm

    Saw confirmation of it somewhere else, though I forget where right now. D'Appolito, maybe....

  15. #120
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    The crossover was designed to give a highly flat system under those conditions.

    Terry showed me a 3 element passive notch circuit that was developed to fix the response and so it sounded quite good.

    This was one of the main incentives for developing the ground plane measuring technique.

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