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Thread: h66000 h9900 h4365

  1. #1
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    h66000 h9900 h4365

    A member asked for the raw data curves for the horn/driver combinations in the Everest II, K2-S9900 and 4365 so here they are.
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    Guido, here's what I got in LEAP substituting in a 1500AL for a 1501AL. These are starting values with optimization set at the knee of the curve so that the proper crossover frequencies are maintained. This results in a slight decrease in voltage drive through the passband, as you mentioned.
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    The dark curves are the target curves using a 1501AL and the light curves are the result of the above values along with the 1500AL. LEAP wanted to put in less shunt resistance so I put in the values I wanted and took them out of the optimization. The values LEAP wanted took too much of a hit in efficiency. (e.g. 18 ohms on LF2 instead of my chosen value of 33 ohms. Interestingly, when I went over this years ago using BB6P it also wanted to put 12 to 18 ohms across that woofer. My opinion is that's too much of a cut.
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    Here are the impedance curves. The actual Everest II 1501AL curve is the light one.
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    Ok, here is a better set of curves. The light gray curve is the 1501AL in the Everest II box. The blue curve is a 1500AL in my personal 5 cu ft (gross) @ 28 Hz box and the red curve is a 1501AL in my personal 5 cu ft (gross) @ 28 Hz box. When I have time I'll run the simulations on these last two curves instead and see what values LEAP comes up with. I don't have time to play with it further tonight.

    You probably don't want the dual drivers dipping below four ohms so you might need to use slightly higher DCR in your coils to make sure that doesn't happen?
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    Senior Member Guido's Avatar
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    Thanks for this awesome work Giskard!

    I'll have a closer look this weekend and add what I find (or not ).
    I also work on it but your input is higly appreciated.
    BLS Reference on Passlabs XA 30.5 + Everest DD66000 clone on Pass XA 100.5

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    Senior Member Guido's Avatar
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    Sensitivity

    We also need to look into the sensitivity thing, right?

    The 1500AL will be more efficient and therefore the whole midrange need to be adapted. Or am I wrong here?
    BLS Reference on Passlabs XA 30.5 + Everest DD66000 clone on Pass XA 100.5

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    I'm taking your drivers to the crate for shipment to Germany this weekend. That's a ten hour day.

    There's maybe a half dB sensitivity difference between the drivers. My concern is the dB drop in the passband for both drivers. They might be a dB hot at the crossover frequency. I'll work on it a bit more even though I am very probably not going to end up running the Everest II type bottom end.

    I'm contemplating running the first 1500AL in a smallish 2.5 cu ft box, possibly sealed. I'll run the second 1500AL as a dedicated subwoofer as per Greg's 1200 Array system, which I prefer to the Everest II. I might end up replacing the second set of 1500AL's with W1500H's. They take less enclosure volume to maintain the same bandwidth. Basically half the cubic footage requirement of the Everest II/4350/4355/4435.

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    Senior Member Guido's Avatar
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    Quote Originally Posted by 4313B View Post
    There's maybe a half dB sensitivity difference between the drivers.
    Hmmm, I mean the fact that with a given 2.83V input the 8 ohm 1500AL draw more current than the 12 ohm 1501AL and so the difference is 2-3dB.
    I attached your 1500AL / 15001AL T/S comparison

    Or am I completely wrong here?
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  10. #10
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    Oh I see what you're asking... do I need to increase the output of the 476BE by something like three dB? I'll figure it all out when I have time.

    I do remember that Greg set the optimization curve for the dual 1501AL's at 96.5 dB... I'll check and see what he set the optimization curve to in the K2-S9900 using the 1500AL-1.

  11. #11
    Senior Member timc's Avatar
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    Guido.

    Yes you will have to increase the impedance of the HF driver, thus reducing the voltage sensitivity. You do this by simply adding a resistor in series with the driver.
    2213 + 2435HPL w/aquaplas + H9800 (Matsj edition)

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    Quote Originally Posted by timc View Post
    Guido.

    Yes you will have to increase the impedance of the HF driver, thus reducing the voltage sensitivity. You do this by simply adding a resistor in series with the driver.
    And then reworking the whole high pass network. Let me know how that works out for you guys.

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    Quote Originally Posted by Guido View Post
    I also work on it but your input is higly appreciated.
    I played around with it a bit more this afternoon. Greg has 1.3 ohms of DCR on that 20 mH coil on the helper woofer. Halving that has an impact on the voltage drive of the helper woofer. Any change in box volume and or tuning is also going to have an impact.

    So... basically you can start with the schematic I posted above and then tweak it to your specific drivers/boxes/fiberfill/tuning/coil DCRs.

    BTW, here's a run using 1500AL's before Greg and Jerry came up with the 1501AL's instead:
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    Senior Member richluvsound's Avatar
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    D,G

    Its wonderful to see a thread of real content .Two gents I admire and respect working on an exciting project and taking the time to post about it .

    thanks , Merry Christmas both and all

    Rich

  15. #15
    Senior Member timc's Avatar
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    Quote Originally Posted by 4313B View Post
    And then reworking the whole high pass network. Let me know how that works out for you guys.

    The reworking when increasing the R component only, is purely linear. Meaning you can just increase/decrease the component values by the % amount of the impedance change. Not sure if this is also true for notches.

    I'm apparantly no gent
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