The 1.75^ft is NET VOLUME, the resonant air space that the speaker actually compresses, you cant count the volume of air sitting inside the port itself, that doesnt compress, that acts as another driver when the speaker hits. but you also cant count the amount of volume that the speaker takes up when its mounted... so you ahve to add those 2 volumes to the amount of volume that the speaker is spec'd for. but then you have to subtract the thickness of the wood. a 12x12x12 box is really only 10.5x10.5x10.5 on the inside, which is only 0.6699^ft, not 1.0^ft as previously thought when making a 12x12x12 box. so if you really want a 12x12x12 box w/ a true 1^ft of volume, you need to add 1.5" to your total outer dimensions when working w/ 3/4" wood. so we'd need a 13.5"x13.5"x13.5" box, which would have 12x12x12 INTERNAL dimensions... and THAT would yeild a true 1^ft.

you get what im saying right? i cant just build a box that yeilds 1.75^ft when measured from the outside... cuz ill be undersized when its all put together... and ill be scratching my head, wondering why my shit doesnt hit as hard as it should.

I could do Fiberglass, im not sure if i wanna do it. If i take out my rear seat backs, thatll earn me about 25-30 lbs to work with. if i switch out my full size steelie spare for a 20 lb spare, thatll earn me another 24 lbs to play with. if i switch to an aluminum jack from an FC, thatll save me about 4 lbs. If i chip out the sound deadner under the carpet, thatll get me another 24 lbs... so i can lose all the additional weight i put on... if i NEED to.