Who's right? Aligment...Vb....Fb...etc

Discussion in 'Home Theater Projects' started by Daniel_AVR, Feb 4, 2004.

  1. Daniel_AVR

    Daniel_AVR Extra

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    Hi,


    I finally choose a Titanic MKIII 12" as a driver to build my vented sub.....

    3 different sources leads me to 3 different aligments....
    I have more tools but didn't counted on these as it's already complicated with these 3 mostly used ones.

    Who should be trusted?


    Dickanson book leads me to; (SBB4 alignment)

    Vb : 2.3 ft^3 with Ql 7
    Fb : 22.5Hz
    Lv : 26.16", 4" i.d. port

    now QB3 alignment which supposedly leads to a smaller box according to text

    Vb : 3.59 ft^3 with Ql 7
    Fb : 20.7 Hz
    Lv : 88.4" !!!, 4" i.d. port

    -------------------------

    WinISD pro leads me to:

    Vb : 3.383 ft^3
    Fb : 20.5 Hz
    Lv : 21", 4" i.d. port

    --------------------------

    BassBox 5.1 leads me to:

    Vb : 2.838 ft^3
    Fb : 19.4 Hz
    Lv : 29.16", 4" i.d. port

    Which one should I use???

    WinISD make the most sense to me.....but would like to have some opinions.

    T&S of drivers are;

    VAS: 2.61 ft^3
    Qms: 6.12
    Qes: .47
    Qts: .44
    Fs: 22.2
    Le: 3.17 MH
    Re: 3.07 Ohm

    Daniel
     
  2. Geoff L

    Geoff L Screenwriter

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    Not going to confront those calculations but will throw a few quick ones out.
    Don't know the X-max on the new T-3 driver but assumed 18mm. Nor the power you plan to use, so figured the usual 250-watt plate amp...

    I know you didn't ask about this but threw a sealed Q.7 in their anyway.

    Sealed
    Q .707
    VB-1.65ft^3
    FC-35.6 Hz
    F3-35.6 Hz


    #1~4th-Ord-Ported
    VB-3.71ft^3
    FB-19.52 Hz
    F3-18.22 Hz
    Port=1 @ 4" x 21.0"

    #2~4th-Ord-ported
    VB-3.47cf^3
    FB-20.31 Hz
    F3- 19.5 Hz
    Port=1 @ 4" x 20.20"

    Take it for what it's worth, but I would think a box volume around 3.6ft^3 or so less driver, bracing and port volume, with tuning around 19 to 20-Hz should make you pretty happy...

    Of the models you used, I'd buy into WinIDS most. Others a little more tech savy may offer more in depth info for you on (what you used and why you came up with what you did)...

    Good Luck
    Geoff
     

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