'Mybox.bas
    '         27/03/1997

     DECLARE FUNCTION MinVentDiam! (Xmax!, Dia!, Fb!, Nbp!)
     DECLARE FUNCTION LongueurTuyau! (dv!, Fb!, vb!, Nbp!)
     DECLARE FUNCTION Freqboite! (dv!, lv!, np, vb!)
     DECLARE SUB SealedBox (QTc!, Vas!, Fs!, Qts!, vb!, Fb!, F3!)
     DECLARE SUB PortFreqRep (Fs!, Qts!, Vas!, vb!, Fbdeb!, FbFin!, Fbinc!)

     CONST ecran = 1, imprimante = 2

     OPEN "scrn:" FOR RANDOM AS #ecran
     OPEN "lpt1:" FOR OUTPUT AS #imprimante

     sortie = ecran
     'sortie = imprimante

     CLS
     Fs = 28
     Qts = .4
     Vas = 210
     vb = 180
     Fbdeb = 26' 15' 27' 24' 15
     FbFin = 31'40'32' 34' 40
     Fbinc = 1' 5'1'2' 5
     'PortFreqRep Fs, Qts, Vas, Vb, Fbdeb, FbFin, Fbinc
     'END
     GOSUB BoxTune
     END
     INPUT " Qts du HP : "; Qts
     INPUT " Vas du HP : "; Vas
     INPUT " Fs  du HP : "; Fs
     QTc = 1.05
     SealedBox QTc, Vas, Fs, Qts, vb, Fb, F3
     PRINT #sortie, QTc, vb, Fb, F3
     PRINT #sortie,
     GOSUB Freqrep
     END
     GOSUB sealed
     END


BoxTune:
       dv = 6.7  'diamŠtre en cm)
       vb = 140'5   'volume de la boite en litres
       np = 2
       PRINT #sortie, USING "    VB = ### litres"; vb
       PRINT #sortie, USING "    DV = #.# cm"; dv
       PRINT #sortie, USING "    NP = #   event(s)"; np
       PRINT #sortie, ""
       FOR lv = 2 TO 15 STEP .1
          Fb = Freqboite(dv, lv, np, vb)
          PRINT #sortie, USING "  Lv=##.#    Fb= ##.# hz"; lv; Fb
          IF (sortie = ecran) THEN a$ = INPUT$(1)
       NEXT lv
       PRINT #sortie, ""
       'END
       vb = 180
       Dia = 35
       Fb = 32' 27
       Nbp = 1
       FOR Xmax = .5 TO 1 STEP .5
          PRINT #sortie, USING "    XMAX=  #.# cm"; Xmax
          PRINT #sortie, USING "    DIAM= ##.# cm"; Dia
          PRINT #sortie, USING "    FB  = ##.# hz"; Fb
          MV1 = MinVentDiam(Xmax, Dia, Fb, 1)
          MV2 = MinVentDiam(Xmax, Dia, Fb, 2)
          PRINT #sortie, USING "    DIAMETRE MINI (1 PORT ) = ###.#"; MV1
          PRINT #sortie, USING "    DIAMETRE MINI (2 PORTS) = ###.#"; MV2
          PRINT #sortie, ""
       NEXT Xmax
       PRINT #sortie, ""
       PRINT #sortie, ""
       PRINT #sortie, USING "    'Tuning' d'une boite de  #### litres … ### HZ"; vb; Fb
       PRINT #sortie, "    (dimensions en  CM)"
       PRINT #sortie, ""
       PRINT #sortie, "    DIAM.     L(1 event)    L(2 events)"
       FOR dv = 2.5 TO 15 STEP .05
         L1 = LongueurTuyau(dv, Fb, vb, 1)
         l2 = LongueurTuyau(dv, Fb, vb, 2)
         PRINT #sortie, USING "   ##.##    ###.##        ###.## "; dv; L1; l2
         IF (sortie = ecran) THEN a$ = INPUT$(1)
       NEXT dv
     END

Freqrep:
     FOR f = 10 TO 500 STEP 2
        FR = (f / Fb) ^ 2
        Dbmag = (10 * LOG(FR ^ 2 / ((FR - 1) ^ 2 + FR / QTc ^ 2))) / LOG10
        PRINT #sortie, f, Dbmag
        a$ = INPUT$(1)
    NEXT f
  RETURN
sealed:
    FOR QTc = .7 TO 2! STEP .05
      SealedBox QTc, Vas, Fs, Qts, vb, Fb, F3
      PRINT #sortie, QTc, vb, Fb, F3
      a$ = INPUT$(1)
   NEXT QTc

'
'
'
'
'
'
      FUNCTION Freqboite (dv, lv, np, vb)
        'dv:diam‚tre de l'‚vent en cm
        'lv:longeur de l'‚vent en cm
        'np : nombre d'‚vents
        'Vb en litres
         CONST alpha = 23562.5
         CONST k = .732
           num = alpha * dv ^ 2 * np
           denom = vb * (lv + k * dv)
           Freqboite = SQR(num / denom)
    END FUNCTION

'
'
'
'
'
'
      FUNCTION LongueurTuyau (dv, Fb, vb, Nbp)
        CONST k = .732
        LongueurTuyau = (23562.5 * dv ^ 2 * Nbp / (Fb ^ 2 * vb)) - (k * dv)
     END FUNCTION

'
'
'
'
'
'
      FUNCTION MinVentDiam (Xmax, Dia, Fb, Nbp)
        pi = ATN(1) * 4
        Sd = pi * (Dia / 100) ^ 2 / 4
        Vd = Sd * Xmax / 1000
        MinVentDiam = 100 * (20.3 * (Vd ^ 2 / Fb) ^ .25) / Nbp ^ .5
      END FUNCTION

'
'
'
'
'
'
      SUB PortFreqRep (Fs, Qts, Vas, vb, Fbdeb, FbFin, Fbinc)
        SHARED sortie
         CONST Ql = 7
         alpha = Vas / vb
         fbsealed = SQR(alpha + 1) * Fs
         QTc = Qts * SQR(alpha + 1)

         GOSUB PortFreqRepTitres

         FOR f = 20 TO 150 STEP 1'2
           PRINT #sortie, USING "  : ###  : "; f;
           FOR Fb = Fbdeb TO FbFin STEP Fbinc
              xFn2 = (f / Fs) ^ 2
              xFn4 = xFn2 ^ 2
              a = (Fb / Fs) ^ 2
              B = a / Qts + Fb / (Fs * Ql)
              C = 1 + a + (Vas / vb) + Fb / (Fs * Qts * Ql)
              D = 1 / Qts + Fv / (Fs * Ql)
              Dbmag = 10 * LOG(xFn4 ^ 2 / ((xFn4 - C * xFn2 + a) ^ 2 + xFn2 * (D * xFn2 - B) ^ 2))
              Dbmag = Dbmag / LOG(10)
              PRINT #sortie, USING "###.# : "; Dbmag;
           NEXT Fb
           FRsealed = (f / fbsealed) ^ 2
           Dbmagsealed = (10 * LOG(FRsealed ^ 2 / ((FRsealed - 1) ^ 2 + FRsealed / QTc ^ 2))) / LOG(10)
           PRINT #sortie, USING " ###.#:"; Dbmagsealed
           IF (sortie = ecran) THEN a$ = INPUT$(1)
         NEXT f

         EXIT SUB


PortFreqRepTitres:
           PRINT #sortie, " "
           PRINT #sortie, " "
           PRINT #sortie, "     Fs  = "; Fs
           PRINT #sortie, "     Qts = "; Qts
           PRINT #sortie, "     Vas = "; Vas
           PRINT #sortie, "     Vb  = "; vb
           PRINT #sortie, " "
           PRINT #sortie, "     Fb (enceinte close) = "; fbsealed
           PRINT #sortie, " "
           PRINT #sortie, "  :------:-";
           FOR Fb = Fbdeb TO FbFin STEP Fbinc
              PRINT #sortie, "------:-";
           NEXT Fb
           PRINT #sortie, "------:"
           PRINT #sortie, "  :      : ";
           FOR Fb = Fbdeb TO FbFin STEP Fbinc
              PRINT #sortie, USING "  ##  : "; Fb;
           NEXT Fb
           PRINT #sortie, "  "
           PRINT #sortie, "  :------:-";
           FOR Fb = Fbdeb TO FbFin STEP Fbinc
              PRINT #sortie, "------:-";
           NEXT Fb
           PRINT #sortie, "------:"
      RETURN
      END SUB

'
'
'
'
'
'
      SUB SealedBox (QTc, Vas, Fs, Qts, vb, Fb, F3)
         Qr = QTc / Qts
         Vr = Qr ^ 2 - 1
         vb = Vas / Vr
         Fb = Qr * Fs
         F3 = Fb * ((1 / QTc ^ 2 - 2 + ((1 / QTc ^ 2 - 2) ^ 2 + 4) ^ .5) / 2) ^ .5
      END SUB