I tried posting this on a previous thread, but it was closed. I am getting ready to buy a JBL P1222 12" sub, and will be running it with 550 watts rms. My question is what box would be ideal for daily listening and still be able to get loud, not really intending to compete in any SPL events.
JBL recomends 1.75 cu ft with 1 4x10.75 port, tuned to 33 hz.
My question is someone here mentioned a box 1.5 to 2.0 cu ft with 2 4x12 ports and indicated that it would be up ~16 db at 56 hz. Does that 56 help any with the fact that my midranges in the front doors are crossed over at 57 hz??? My fear is that the sub would do very well at low frequence, but roll off rather quickly above 50 hz(?).
Anyone with WinISD might be able to plot the box with 2 ports for me, and post here what it would do?
It's going in a PT Cruiser hatchback.
Here are parameters:
THIELE-SMALL PARAMETERS of JBL P1222 DVC
VOICE COIL DC RESISTANCE : R EVC (OHMS ) . . . . . . 1.00
VOICE COIL INDUCTANCE @ 1KHZ: LEVC (MH) . . . . . . . 1.10
DRIVER RADIATING AREA : S D
(IN 2) . . . . . . . . 87.11
SD . . . . . . 562.00
MOTOR FORCE FACTOR : B L (T M) . . . . . . . . 10.00
COMPLIANCE VOLUME : V AS (FT 3) . . . . . . . . 1.53
VAS (LITERS ) . . . . . 43.30
SUSPENSION COMPLIANCE : C MS (µ M/N) . . . . 96.00
MOVING MASS , AIR LOAD : M MS (GRAMS ). . . . 323.00
MOVING MASS , DIAPHRAGM : M MD (GRAMS ) . . . 315.80
FREE -A IR RESONANCE : F S (H Z) . . . . . . . . 28.60
MECHANICAL Q: Q MS . . . . . . . . . . . 9.04
ELECTRICAL Q: Q ES . . . . . . . . . . . . 0.58
TOTAL Q: Q TS . . . . . . . . . . . . 0.55
MAGNETIC -G AP HEIGHT : H AG (IN ) . . . . . . . . 0.48
HAG (MM ) . . . . . . . 12.00
VOICE -C OIL HEIGHT : H VC (IN ) . . . . . . . . 1.58
HVC (MM ) . . . . . . . 40.00
MAXIMUM EXCURSION : X MAX (IN ) . . . . . . . . .56
XMAX (MM ) . . . . . . 14.00