[. . . ] Power Acoustik FBX Woofers Congratulations on your purchase of one of the finest woofers available for your vehicle today. [. . . ] 3. 36 0. 6 0. 5105 0. 6" Recommended box sizes Model FBX-10 FBX-12 FBX-15 Sealed Box Size Ported Box Size Tune Freq. # of Ports Port (dia x length) . 75 cubic feet 1. 5 cubic feet 40 Hz 1 3" x 5. 7" 1. 0 cubic feet 2. 0 cubic feet 30 Hz 1 3" x 8. 4" 2. 0 cubic feet 2. 0 cubic feet 35 Hz 2 3" x 12. 5" · · · · · · · · Determine the dimensions of your enclosure. Be certain the box dimensions that you have designed will fit in the location you have chosen in your vehicle. Sometimes making a cardboard box with the same outside dimensions is helpful. Building the Enclosure It is recommended to use ¾ inch thick MDF (medium density fiberboard) for your box. Use a "T" square to verify precise right angle cuts before you assemble the box. [. . . ] Please look and follow the diagrams closely to insure maximum woofer performance. Parallel voice coil configuration + + Amplifier 2-ohm Load - + - 4-ohm + Amplifier + + - - - Series voice coil configuration 4-ohm 4-ohm Amplifier 8-ohm Load Series/Parallel voice coil configuration 4-ohm 2-ohm Amplifier 4-ohm Load 4-ohm 4-ohm [. . . ]